REPÚBLICA DE CABO VERDE
Power Transmission and Distribution System
Development Project in six Island of Cape Verde
Lot 1
Rehabilitation, Reinforcement and
Expansion of MV and LV Networks in
Santiago, Fogo and Maio Islands
Bidding Documents
Volume III
Section VI. Technical Specifications and Drawings
LOT1
PTDSD Project: Part I - Rehabilitation,
Reinforcement and Expansion of MV and LV
Networks – LOT1 and LOT2
Vol III, lot 1 – Technical Specification and
Drawings
Page 2 of 150
General Requirements
Scope of Supply
Section VI. Technical Specifications and Drawings
Table of Contents
Scope of work ................................................... 7
1. INTRODUCTION ................................................................................................................... 7
1.1. SANTIAGO ISLAND SCOPE ............................................................................................. 7
1.2. FOGO ISLAND SCOPE ................................................................................................... 10
1.3. MAIO ISLAND SCOPE ................................................................................................... 13
2. UNDERGROUND MV NETWORK SPECIFICATIONS ................................................... 15
2.1. SPECIFICATION OF MV CABLES ................................................................................ 15
2.2. MV CABLES AND COMMUNICATION NETWORKSUPPLY .................................... 18
2.2.1. MV cables with a cross section of 500 mm2 ......................................................................................18
2.2.2. MV cables with a cross section of 240 mm2 ......................................................................................18
2.2.3. MV cables with a cross section of 120 mm2 ......................................................................................20
2.2.4. MV cables with a cross section of 70 mm2 ........................................................................................21
2.2.5. Communication Network ..................................................................................................................22
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Networks – LOT1 and LOT2
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2.3. MV CABLES TRENCH .................................................................................................... 24
2.3.1. TRENCH WORKS ................................................................................................................................30
2.4. CABLE ACCESSORIES ................................................................................................... 34
2.5. PLASTIC PROTECTION ................................................................................................ 35
3. DISTRIBUTION STATIONS, SWITCHING STATIONS AND SECONDARY
SUBSTATIONS ............................................................................................................................ 35
3.1. PALMAREJO 20 KV SUBSTATION ............................................................................. 35
3.1.1. General .............................................................................................................................................35
3.1.2. Specifications of the new 20 kV switchgear .......................................................................................37
3.1.3. MV/LV transformers .........................................................................................................................47
3.1.4. MV/LV transformers .........................................................................................................................48
3.1.5. AC and DC Auxiliary Voltages ............................................................................................................48
3.1.6. Earthing system.................................................................................................................................49
3.1.7. Civil works .........................................................................................................................................50
3.2. GAMBOA 20 KV SUBSTATION ................................................................................... 52
3.2.1. General .............................................................................................................................................52
3.2.2. Specifications of the new 20 kV switchgear .......................................................................................52
3.2.3. Earthing system.................................................................................................................................62
3.2.4. Power cable and control cable arrangement .....................................................................................62
3.2.5. Civil works .........................................................................................................................................62
3.3. SWITCHING STATIONS ............................................................................................... 63
PTDSD Project: Part I - Rehabilitation,
Reinforcement and Expansion of MV and LV
Networks – LOT1 and LOT2
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3.3.1. General .............................................................................................................................................63
3.3.2. Existing MV switchgear .....................................................................................................................66
3.3.3. The MV cubicle to supply and install .................................................................................................66
3.3.4. MV/LV Power Distribution Transformers ..........................................................................................72
3.3.5. LV distribution Fuse Boards ...............................................................................................................73
3.3.6. AC Panel Board..................................................................................................................................73
3.3.7. Rectifier / Battery / DC Switchboard .................................................................................................74
3.3.8. Lighting and Small Power ..................................................................................................................75
3.3.9. Earthing System ................................................................................................................................75
3.3.10. Safety Equipment .........................................................................................................................77
3.3.11. Civil Works ....................................................................................................................................77
3.4. MV/LV SECONDARY SUBSTATIONS ......................................................................... 78
3.4.1. General .............................................................................................................................................80
3.4.2. MV Switchgear Specification .............................................................................................................81
3.4.3. Directional Fault Current Indicator for Uderground Network ............................................................84
3.4.4. MV/LV Power Distribution Transformer ............................................................................................86
3.4.5. Transformer feeders..........................................................................................................................87
3.4.6. Low voltage distribution fuse board ..................................................................................................88
3.4.7. Civil Works ........................................................................................................................................94
3.4.8. Earthing Systems ...............................................................................................................................96
3.4.9. Accessories ........................................................................................................................................98
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4. MV OVERHEAD NETWORK............................................................................................. 98
4.1. GENERAL ........................................................................................................................ 98
4.2. SCOPE OF WORK ......................................................................................................... 100
4.3. EQUIPMENT SPECIFICATION .................................................................................. 104
4.3.1. Supporting structures - Poles .......................................................................................................... 104
4.3.2. Cross arms ....................................................................................................................................... 106
4.3.3. Insulators ........................................................................................................................................ 107
4.3.4. Aerial Conductor Cables .................................................................................................................. 108
4.3.5. Pole mounted secondary substation ............................................................................................... 108
4.3.6. Earthings ......................................................................................................................................... 112
4.3.7. Lightening arresters ........................................................................................................................ 114
4.3.8. Outdoor air breaking switch ............................................................................................................ 114
4.3.9. Outdoor Load Break SwitchDisconnector with Remote Control Unit ............................................... 114
4.3.10. Directional Fault Current Indicator for Overhead 20 kV Network ............................................... 117
4.4. OVERHEAD NETWORK CONSTRUCTIONS PROCEDURES ................................. 120
4.4.1. Anchoring and erection of metallic structure .................................................................................. 120
4.4.2. Foundations .................................................................................................................................... 121
4.4.3. Conductor stringing and sagging ..................................................................................................... 125
5. LOW VOLTAGE NETWORK ........................................................................................... 128
5.1. SCOPE OF WORK ......................................................................................................... 128
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5.2. LV NETWORK EQUIPMENT SPECIFICATION ....................................................... 131
5.2.1. Cables ............................................................................................................................................. 131
5.2.2. Supporting structures - Poles .......................................................................................................... 134
5.2.3. Distribution Street Fuse Cabinet 230/400 V .................................................................................... 135
5.2.4. Flush Mounted Fuse Cabinet 230/400 V .......................................................................................... 138
5.2.5. Luminary for wood pole installation................................................................................................ 139
5.2.6. Street light poles and Luminary for underground networks ............................................................ 140
5.2.7. Energy meters ................................................................................................................................. 142
6. SITE WORKS .................................................................................................................... 144
6.1. SUPPLY AND WORKS UNDER CONTRACTOR RESPONSIBILITY ..................... 144
6.2. PRELIMINARY MEASURES ....................................................................................... 144
6.3. SIGNALLING AND PROTECTION ............................................................................. 144
7. DRAWINGS ....................................................................................................................... 146
7.1. COMMON DRAWINGS ................................................................................................ 146
7.2. SANTIAGO DRAWINGS .............................................................................................. 147
7.3. FOGO DRAWINGS ....................................................................................................... 149
7.4. MAIO DRAWINGS........................................................................................................ 150
PTDSD Project: Part I - Rehabilitation,
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Networks – LOT1 and LOT2
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SCOPE OF WORK
1. INTRODUCTION
The present specifications cover the equipment and works necessary to improve in
Santiago, Fogo and Maio Island the installations hereafter:
1.1. SANTIAGO ISLAND SCOPE
Item
Praia City Infrastructure Installation
1 New Palmarejo Distribution Station
New Palmarejo Distribution Station in a new 40x12,5 m2 building, equipped with
double bus bar switchgear, for physical separation between Generation and
Distribution Installations - Praia City.
All the generation units, namely diesel Power Station, Solar Power Station, TRC
Power Station shall be connected to the Main Palmarejo Power station bus bar
and all the MV network feeders and 20/60 kV Substation shall be connected to
the new distribution station. As a main distribution station for all Santiago Island
Network it is decided for the implementation of a double bus bar switchgear to
decrease the risk of general black-out in case of bus bar failure and allow the
maintenance operation.
All the circuit breakers to be installed shall be controlled by efficient protections
units and they shall be also prepared for remote control by Scada system.
2 Rehabilitation of Gamboa Distribution Station
Full rehabilitation of Gamboa Distribution Station with replacement of the 25 years
old switchgear by new single bus bar switchgear - Praia City.
Gamboa Distribution Station shallcontinue being a extremely important point for
operation and protection in hall Praia distribution network. The advanced age of
the existing switchgear and its bad condition of exploitation request its
rehabilitation by full replacement.
All the circuit breakers to be installed will be controlled by efficient protections
units and they will be also prepared for remote control by Scada system.
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3 New Achada Grande Switching Station in Praia City
New Achada Grande Switching Station and its connection to Lem Ferreira
Switching Station by two trunk line feeders (240 Al) - Praia City.
This Achada Grande Switching Station and the two trunk lines connection in a
loop will be the way to supply energy in a good condition to one of the most
important and promising industrial and residential plateau of Praia City.
All the incoming and outgoing cubicles shall be equipped with circuit breakers
controlled by efficient protections units. They shall be also prepared for remote
control by Scada system.
4 Reinforcement of interconnection between Gamboa Distribution Station and
Sao Filipe Switching Station in Praia City
The installation of one underground trunk line feeder with a 500 mm2 Aluminum
cable between this two stations will permit a load flow up to 15 MVA between this
tow areas of Praia city.
The connection between this two stations in a near future has to be enough strong
to permit the load flow in both sense and partial supplying Gamboa in emergency
case, whenever the existing connection Palmarejo / Gamboa fails.
At the same time the already existing 500 mm2 Aluminium cable connecting the
new Wind Farm and Gamboa SS shall interrupted and redirected to the Sao
Filipe Switching Station in order to enable the existence of two trunck lines
between Gamboa and Sao Filipe.
5 Praia City MV Network Rehabilitation
Rehabilitation of 11 MV/LV 25 years old and dilapidated secondary substation at
Praia MV network by replacing MV switchgear and LV Fuseboard. - Praia City.
6 Extension of LV Networks with 70/35 mm2 ABC cables and rehabilitation by
replacing of thin Cu bare conductors by overhead 70/35 mm2 ABC cables in 13
km - Praia City
Inland Santiago Island Infrastructure Installation
7 Sao Jorge dos Orgãos MV network upgrade and rehabilitation
Upgrade from 10 kV to 20 kV and rehabilitation of dilapidated Sao Jorge dos
Orgãos 25 years old MV Network, including MV Overhead Lines and three MV/LV
Secondary Substations, by replacing of MV Switchgear, Power transformer and
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LV Fuse board and new buildings - Sao Jorge dos Orgãos City (Municipality).
8 Santa Cruz Municipality MV and LV Network rehabilitation
Expansion and Rehabilitation of dilapidated Santa Cruz Municipality MV Network,
including 1 km of new 70 mm2 Aluminum MV Underground Line installation, one
new MV/LV secondary substation installation and three partial rehabilitation of
MV/LV Secondary Substations, by replacing of MV Switchgear, LV Fuse board
and new buildings.
This Tasks includes also extension an rehabilitation of 11 km of LV overhead
70/35 mm2 ABC cable network
9 Tarrafal Municipality MV and LV Network extension and rehabilitation
Expansion and Rehabilitation of dilapidated Tarrafal Municipality MV Network,
including 3,8 km of new 70 mm2 Aluminum MV Underground Line installation,
four new MV/LV secondary substation installation and one full rehabilitation of
MV/LV Secondary Substations, by replacing of MV Switchgear, Power
Transformer LV Fuse board and new buildings.
This Tasks also includes extension an rehabilitation of 13 km of LV overhead
70/35 mm2 ABC cable network
10 Calheta Municipality MV Network rehabilitation and LV Network extension
Rehabilitation of dilapidated Calheta City MV Network, including five partial
rehabilitation of MV/LV Secondary Substations, by replacing of MV Switchgear,
LV Fuse board and civil building rehabilitations.
This Tasks also includes extension an rehabilitation of 11 km of LV overhead
70/35 mm2 ABC cable network
11 Extension of LV Networks with 70/35 mm2 ABC cables and rehabilitation by
replacing of 13 km of thin Cu bare conductors by overhead 70/35 mm2 ABC
cables in Praia City
Monitoring and remote control of the Santiago Network
11 Scada system Installation
A System Control and Data Acquisition (SCADA) will be installed for monitoring
and remote control of the main distribution and switching station in all Santiago
Island. With this installation it is expected to have a very efficient control and
operation of all the system and a very significant reduction of energy outage time
what means better service quality and better performance. The communication
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network shall be installed but Scadasytemand RTU are not included in the scope
of supply.
13 Fault current indicator installation on underground Network
Installation of 104 intelligent programmable fault current indicator for 10 to 24 kV
underground network, with flashing lighting, over the doors of the existing Praia
City MV/LV secondary substations to easily locate in witch section of a line
between two S/S has occurred a phase to ground or phase to phase fault. With
this equipments the energy outage in a MV network feeder, specially if it is a ring
closed feeder, will be significantly reduced. At the same time all new MV
switchboard in the expanded or rehabilitated S/S will be equipped with this divice.
14 Fault current indicator installation on overhead Network
Installation of 74 pole mounted fault current indicator for MV overhead lines, with
flashing lighting, on the existing Santiago Island Overhead Network to easily
locate in witch direction of the grid has occurred a phase to ground or phase to
phase fault. The flashing lighting can be visible 2 or 3 km distance. With this
equipments the energy outage in a MV network feeder will be significantly
reduced.
15 OHL pole mounted load switch break disconnector installation
45 pole mounted load break switch disconnector, with remote control, will be
strategically installed in all Santiago overhead network derivations in order to
facilitate the operations and maintenance. With this equipments the energy
outage in a MV network feeder will be significantly reduced.
Rural Electrification
16 New Electrifications
Extension of 45 km of MV 54,6 mm2 Aster cabel OHL to 33 rural villages of all
Santiago Municipalities for electrification, with 27 pole mounted 50/100 kVA
secondary substations and 73 km of low voltage network with 70 mm2 Aluminium
overhead ABC cable to supply energy to more than 1300 families.
1.2. FOGO ISLAND SCOPE
Item
MV/LV network reinforcement, expansion and rehabilitation
PTDSD Project: Part I - Rehabilitation,
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1 Fogo MV network upgrade to 20 kV - Trunk Line Sao Filipe Patim
The existing line São Filipe / Patim / Genebra which supplies all Southern Sao
Filipe Municipality Region and all Santa Catarina do Fogo Municipality was
installed 42 years ago. Today it is a 16 mm2 cuprum conductor overhead line with
concrete poles in a very advanced stage of degradation, operated on 15 kV.
This line will be replaced by a combination of 2 km of 240 mm2 aluminum
conductor underground cable with 9 km of 148 mm2 aster conductor overhead
trunk line from Sao Filipe City to Patim Village, to be operated on 20 kV. From this
trunk line a 3,5 km derivation with 54,6 mm2 aster conductor overhead line to
Genebra and a derivation with 54,6 mm2 aster conductor overhead line to Monte
Grande will replace the existing, also degraded lines.
7 MV/LV 50/100 kVA secondary substations along the feeder will be rehabilitated
and upgraded do 20 kV.
One new switching station in a 6x4 m2 masonry building will be installed at the
end of the trunk line and it will be equipped with one circuit breaker incoming
cubicle and 3 circuit breakers outgoing cubicles, controlled by efficient protections
units (over current, phase to phase and phase to ground faults protection) to
protect and operate the feeders to Genebra, Monte Grande and CovaFigueira in
order to guarantee a very efficient operation in case of faults. The Switching
station will also be prepared for future remote control from São Filipe Power
Station.
2 Expansion and rehabilitation of Fogo MV Network
To expand the MV network to new residential areas or to prevent the overload of
some existing secondary substation and, in order to avoid the voltage drop in LV
network 3,9 km of aluminum conductor 120 mm2 underground 12/20 kV cable
and 6 new 250 kVA MV/LV secondary substations will be installed in several
quarters of São Filipe and Mosteiros City.
Two MV/LV secondary substations will completely rehabilitated including new
masonry building.
With the MV cable extension a close loop will be created in São Filipe City
network in order to reduce the energy outage time in case of failures.
3 New Ponta Verde switching station
A new switching station in a 6x4 m2 masonry building equipped with one circuit
breaker incoming cubicle and 3 circuit breakers outgoing cubicles, controlled by
PTDSD Project: Part I - Rehabilitation,
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efficient protections units (over current, phase to phase and phase to ground
faults protection) will be installed at Ponta Verde, northern side of São Filipe
Municipality, in order to guarantee a very efficient operation in case of faults
upstream. The Switching station will also be prepared for future remote control
from São Filipe Power Station.
4 LV Network rehabilitation and expansion
Extension of LV Networks with 26 km of OHL 70/35 mm2 ABC cables and 6 km
of UGL Al 50/95/185 mm2 and rehabilitation by replacing of 13 km of existing thin
Cuprum bare conductors by overhead 70/35 mm2 aluminum ABC cables in
several São Filipe City quarters and Mosteiros City.
Installation of pole mounted load switch breaker in OHL and fault current
indicators
5 Fault current indicator installation on underground Network
Installation of 15 intelligent programmable fault current indicator for 10 to 24 kV
underground network, with flashing lighting, over the doors of the existing Fogo
MV/LV secondary substations to easily locate in which section of a line between
two S/S has occurred a phase to ground or phase to phase fault. With this
equipments the energy outage in a MV network feeder, especially if it is a ring
closed feeder, will be significantly reduced.
6 Fault current indicator installation on overhead Network
Installation of 22 pole mounted fault current indicator for MV overhead lines, with
flashing lighting, on the existing Fogo Island Overhead Network to easily locate in
which direction of the grid has occurred a phase to ground or phase to phase
fault. The flashing lighting can be visible 2 or 3 km distance. With this equipments
the energy outage in a MV network feeder will be significantly reduced.
7 OHL pole mounted load switch break disconnector installation
9 pole mounted load break switch disconnectorwith remote control will be
strategically installed on the Fogo island overhead network derivations in order to
facilitate the operations and maintenance. With this equipments the energy
outage in a MV network feeder will be significantly reduced.
Rural Electrification
8 New Electrifications
Extension of 12 km of MV 54,6 mm2 Aster cable OHL to 11 rural villages of all
Fogo Island Municipalities for electrification, with 9 pole mounted MV/LV 50/100
PTDSD Project: Part I - Rehabilitation,
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kVA secondary substations and 23 km of low voltage network with 70 mm2
Aluminum overhead ABC cable, to supply energy to more than 257 families.
It is necessary to fence off the operating zone and post notices on prominent areas.
Contractor shall prepare, submit and implement after approval by the Project
Manager a Safety Management Plan, which shall include but not limited to:
1.3. MAIO ISLAND SCOPE
Item
MV/LV network reinforcement, expansion and rehabilitation
1 Trunk line Torril Power Station / Morro
The west coast of Maio Island is supplied by a 34,4 mm2 aster conductor
overhead line, operated on 20 kV, which causes so many problems to the
distribution services and to the Power station's generator sets due to the
extremely aggressive environment and various design mistake and installation
defects. The line route is in conflict with new plans for Maio airport expansion.
Because of that and in order to increase the transmission capacity, it is decided
to replace the existing line from the Power Station up to Morro Village, by a 10,5
km of 240 mm2 aluminum underground cable trunk line, which will supply all Maio
City MV/LV secondary substations, along the way, in a ring system.
A second circuit with 2,4 km of 120 mm2 aluminum underground cable will be
installed in Maio city in order to create a closed loop in the city.
A new switching station in a 6x4 m2 masonry building, equipped with one circuit
breaker incoming cubicle and 3 circuit breakers outgoing cubicles, controlled by
efficient protections units (over current, phase to phase and phase to ground
faults protection) will be installed at Morro Village, in order to guarantee a more
efficient operation in case of faults on the upstream network. The Switching
station will also be prepared for future remote control from São Filipe Power
Station.
With this installations the transmission capacity along the promising Maio west
coast increase up to 9 MVA
Two new MV/LV secondary substation will be installed at Maio City new
residential area according to the Municipality Urbanistic Development Plan.
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2 Closing of Maio MV Ring
A new 54,6 mm2 aster conductor overhead line, with silicone insulators, from
FigueiraSeca Village to Alcatrás / PilãoCão Villages, will be installed in order to
implement a completely closed MV ring around all Maio Island. Two new MV/LV
50 kVA secondary substations will be installed in masonry buildings at Pilãocao
and Alcatrás.
3 Maio MV overhead line rehabilitation and upgrade
14 km of existing, and extremely dilapidated, overhead line will be rehabilitated
with replacement of all glass insulators by silicone insulators, and it will be
upgraded by replacement of the degraded 34,4 mm Aster conductor by 54 mm2
Aster conductor. Some structural poles and cross arms degraded by corrosion will
also be replaced. The purpose of this rehabilitation is to avoid the high cost of the
frequent outages for line cleaning and maintenance (today it has to be done every
2 month) which, with silicone insulators, is expectable to be no needed at least
for 7 to 10 years after installation.
5 pole mounted MV/LV secondary substations will be rehabilitated with
replacement by new ones in a masonry cabinet.
10 km of OHL from Torril Power Station to Figueira Dom João has not been
included on the scope because it is located inside a environmental protected area.
4 New Pedro Vaz switching station
A new switching station in a 6x4 m2 masonry building equipped with one circuit
breaker incoming cubicle and 2 circuit breakers outgoing cubicles, controlled by
efficient protections units (over current, phase to phase and phase to ground
faults protection) will be installed at Pedro Vaz in order to guarantee a very
efficient operation in case of faults upstream. The Switching station will also be
prepared for future remote control from the Power Station.
5 LV Network rehabilitation and expansion
The LV Networks in all Maio Island will be rehabilitated or extended in 9 km with
70/35 mm2 ABC cables.
Installation of pole mounted load switch breaker in OHL and fault current
indicators
6 Fault current indicator installation on overhead Network
10 pole mounted fault current indicator, with flashing lighting, will be installed on
the MV overhead network to easily locate in which direction of the grid has
PTDSD Project: Part I - Rehabilitation,
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occurred a phase to ground or phase to phase fault. The flashing lighting can be
visible 2 or 3 km distance. With this equipments the energy outage in a MV
network feeder will be significantly reduced.
7 OHL pole mounted load switch breaker installation
5 pole mounted load switch breakers with remote control will be strategically
installed on the Fogo island overhead network derivations in order to facilitate the
operations and maintenance. With this equipments the energy outage in a MV
network feeder will be significantly reduced.
The scope of work includes the design, the supply, all the civil works and adaption
supply and work for the installation, the connection to the existing equipment, the test
and commissioning except where it is clearly written “ installed by ELECTRA”
2. UNDERGROUND MV NETWORK SPECIFICATIONS
2.1. SPECIFICATION OF MV CABLES
The cables to be supplied shall be single core, XPLE (IEC 60502-2) aluminium cables,
with the characteristics of those used in and standardized for ELECTRA networks, type
LXHIOV, 12/20 kV, in accordance with Portuguese standards, and which constitution is
as follows:
Conductor:
Aluminium,circular, stranded compacted, conductor in accordance to IEC 60228, with
the cross sections of70, 120,240or 500 mm2 as defined later on.
Insulation:
The insulation shall consist of one layer of extruded cross-linked poly-ethylene (XLPE)
obtained by either peroxide dry curing or silane process according to IEC 60502.
Conductor semi-conducting screen:
This screen shall consist of a semi-conducting synthetic material, extruded by double
extrusion process on the conductor and on insulation. It should be continuous, with a
minimum thickness of 0.5mm, with no rough surfaces and keeping a close contact with
the insulation. The semi-conducting screen shall withstand the temperature in the
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conductor and the admissible mechanical forces in the insulation, and shall have no
detrimental effect on the conductor or on the insulation.
Insulation semi-conducting screen:
This screen shall consist in one of the following alternatives to be specified by the
Bidders:
A layer of the extruded semi synthetic semi-conducting material, bonded to the
insulation, and it should be possible to separate it from the insulation without the
aid of special tools. In this case triple extrusion is required.
A semi-conducting coating plus plastic semi-conducting tape (non water
absorbent) wound helically with superposition over it.
Metallic screen:
The metallic screen shall consist of a copper tape or a copper tape plus copper wires
moulded to the cable and bonded to the over-sheet conjugated with a coating of hydro-
expansive powder if the manufacturer deems it advisable. The construction of the
metallic screen shall guarantee a perfect contact with the insulation semi-conducting
screen to constitute an equipotential system and shall be considered stanch to water
from the outer metallic screen. The dimensional characteristics shall be calculated in
such a way as to ensure a permissible short circuit current of 1 kA during 1 second,
without causing overheating in the close layers.
Hydro-expansive layer:
It shall consist of a tape applied upon the metallic shield, able to increase its volume in
the presence of water, in order to ensure the tightness of the cable. If the copper shield
and hydro-absorbent powder is used and ensure the tightness of the cable, the hydro-
expansive tape may be dispensable.
Over-sheath:
The over-sheath shall consist of a compound, applied by an extrusion process,
adequate to the rated cable temperatures, of polyvinyl chloride (PVC) coloured black,
with anti-termite repellent, non-poisoning type, adequate for termite types
“OdontermusFormusanus” and “CoptotermesFrenchi”. The chemical product used as
repellent shall be stated by the Bidders. PVC characteristics shall comply with IEC
60502. The nominal thickness of the over-sheath shall be 3.0 mm and the maximum
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deviation in thickness, in any particular point, shall be not greater than 25% of the
nominal value.
The cables shall have the following main characteristics:
LXHIV 1x70 LXHIV 1x120 LXHIV 1x240 LXHIV 1x500
Conductor
Material Aluminium Aluminium Aluminium Aluminium
Cross section (mm2) 70 120 240 500
Number ofwires 12 15 30 53
Conductor screen
Material
Extruded semi-
conducting
compound
cross linked
Extruded semi-
conducting
compound
cross linked
Extruded semi-
conducting
compound
cross linked
Extruded semi-
conducting
compound
cross linked
Nominal thickness (mm) 0,6 0,6 0,6 0,6
Minimum thickness (mm) 0,5 0,5 0,5 0,5
Insulation
Material XLPE XLPE XLPE XLPE
Nominal thickness (mm) 5,5 5,5 5,5 5,5
Minimum thickness (mm) 4,85 4,85 4,85 4,85
Insulation Screen
Material
Extruded semi-
conducting
compound
cross linked
Extruded semi-
conducting
compound
cross linked
Extruded semi-
conducting
compound
cross linked
Extruded semi-
conducting
compound
cross linked
Nominal thickness (mm) 0,6 0,6 0,6 0,6
Minimum thickness (mm) 0,5 0,5 0,5 0,5
Bedding tape
Material
Semiconductive
tape
Semiconductive
tape
Semiconductive
tape
Semiconductive
tape
Nominal thickness 0,13 0,13 0,13 0,13
Metallic screen
Material
Cooper tape +
Cooper Wire
Cooper tape +
Cooper Wire
Cooper tape +
Cooper Wire
Cooper tape +
Cooper Wire
Section (mm2) 16 16 16 16
Outer sheath
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Material PVC PVC PVC PVC
Colour Black Black Black Black
Nominal thickness (mm) 1,9 3,0 3,0 3,0
Minimum thickness (mm) 1,5 2,25 2,25 2,25
Electric characteristics
Cond. Resit. at 20ºC - Ω/km 0,443 0,253 0.125 0,0605
Screen (20ºC) - Ω/km 1,1 1,1 1.1 1,1
2.2. MV CABLES AND COMMUNICATION NETWORKSUPPLY
2.2.1. MV cables with a cross section of 500 mm2
The total linear length of the necessary cable of 500 mm2 is 43.500 km. The bidders
are requested to use a delivery length of 1000m per drum. The length in the table
below is only given for information and includes already overlength for connection.
The cables are to be installed as follows:
2.2.2. MV cables with a cross section of 240 mm2
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The total linear length of the necessary cable of 240 mm2 is 62 km. The bidders are
requested to use a delivery length of 1500m per drum. The length in the table below
is only given for information and includes already overlength for connection.
The cables are to be installed as follows:
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2.2.3. MV cables with a cross section of 120 mm2
The total linear length of the necessary cable of 120 mm2 is 18 km. The bidders are
requested to use a delivery length of 1500m per drum. The length in the table below
is only given for information and includes already overlength for connection.
The cables are to be installed as follows:
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2.2.4. MV cables with a cross section of 70 mm2
The total linear length of the necessary cable of 70 mm2 is 19 km. The bidders are
requested to use a delivery length of 1500m per drum. The length in the table below is
only given for information and includes already overlength for connection.
The cables are to be installed as follows:
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2.2.5. Communication Network
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In Santiago island it shall be installed a Scada System for remote control of MV
Network, namely all Distribution and Switching Stations. In order to enable the
communication between the distribution stations, the switching stations and the
Scada System to be located at Electra’s Gamboa Building a communications network
must be installed. A 12Foptical fiber cablewill be used for underground installation to
interconnect the stations as indicated in the table below.
Cable extremities Drawing nº Length
km
1 L. Ferreira SW/S Ac. Grande SW/S 2.9
2 Gamboa D/S S.Filipe SW/S 9
3 Palmarejo PS Palmarejo DS 0,3
In Praia city some communication optical fiber cable are going to be installed during
2012 year by the already ongoing distribution project.
The communication cable will be installed in the same trenches as the MV Cables
whenever the routs will be coincident. When the routs are not coincident the OPC
shall be installed on its own trench. The cable will not be buried directly on the sand.
It will be used anuPCV pipe for mechanical protection.
For the interconnection of the distribution and switching station in rural area as
indicated in the table below it shall be used the ADSS optical fibre cable,self-
supportedfor overhead installation, using the poles of existing overhead MV network
with the maximum span 250 meters. In this case the supply includes all the
accessories for the, installations.
Cable extremities Drawing nº Length
km
1 Calheta 60/20 kVSS Tarrafal D/S 22
2 Calheta 60/20 kVSS StaCatarina D/S 16
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3 Calheta 60/20 kVSS Sta Cruz D/S 12
The Scada System and the RTU are not included on this scope.
The fiber cable will meet the requirement of standard IEC 60794-1 and the main
characteristics shall be as indicated in the table below:
Type of Installation Underground installation
in uPVC pipe
Self supported for
overhead installation in
poles
Type Mono-mode Mono-mode
Number of optical fibers 12 12
Sub cable diameter **** ***
Sub cable cover reinforced reinforced
Outer cover Black polyethylene Black polyethylene
Outer diameter 6,5 13,8
Temperature range -30ºC to 60ºC -30ºC to 60ºC
Permanent Traction (EDS) *** kN *** kN
Working Traction (EDS) *** kN *** kN
2.3. MV CABLES TRENCH
There are eight types of trenches for the MV and communication cables:
Type IA - MV trench profile, 60 cm width, 120 cm deep, for one MV single core cable
type, cross section up to 500 mm2, laid in a side by side arrangement, protected as
defined in drawing no. 0.0.19 and it is used either for cable XHIOV 3x1x70, XHIOV
3x1x120, XHIOV 3x1x240 or for XHIOV 3x1x500.
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Type IB - MV trench profile, 60 cm width, 120 cm deep, for one MV single core cable
type, cross section up to 500 mm2, laid in a side by side arrangement, plus triple pipe
for communication cable, protected as defined in drawing no. 0.0.19 and it is used
either for cable XHIOV 3x1x70, XHIOV 3x1x120, XHIOV 3x1x240 or for XHIOV
3x1x500.
Type IIA - MV trench profile, 60 cm width, 120 cm deep, for two MV single core cable
type, cross section up to 240 mm2,laid in parallel, both in trefoil arrangement,
protected as defined in drawing no. 0.0.19 and it is used either for cable XHIOV
3x1x70, XHIOV 3x1x120 or for XHIOV 3x1x240.
Type IIB - MV trench profile, 60 cm width, 120 cm deep, for two MV single core cable
type, cross section up to 240 mm2, laid in parallel, both in trefoil arrangement, plus
triple pipe for communication cable, protected as defined in drawing no. 0.0.19 and it
is used either for cable XHIOV 3x1x70, XHIOV 3x1x120 or for XHIOV 3x1x240.
Type IIC - MV trench profile, 90 cm width, 120 cm deep, for two MV single core cable
type, cross section 500 mm2,laid in parallel, both in trefoil arrangement, protected as
defined in drawing no. 0.0.19 and it is used for cable XHIOV 3x1x500.
Type IID - MV trench profile, 90 cm width, 120 cm deep, for two MV single core cable
type, cross section 500 mm2,laid in parallel, both in trefoil arrangement, plus triple
pipe for communication cable, protected as defined in drawing no. 0.0.19 and it is
used for cable XHIOV 3x1x500.
Type IIIA - MV trench profile, 60 cm width, 120 cm deep, for road crossing as defined
in the drawing 0.0.21.
Type IIIB - MV trench profile, 90 cm width, 120 cm deep, for road crossing as defined
in the drawing 0.0.21
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The individual trench lengths to be built are defined in the following tables where it is
also mentioned the drawing where cable route is defined as well as trench type.
Trenches for cables inSantiago Islandare as follow:
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Trenches for cables in Fogo Island are as follow:
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Trenches for cables in Maio Island are as follow:
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2.3.1. TRENCH WORKS
2.3.1.1. Trench Opening
Trench location and dimension are indicated in project drawing. Contractor will carry
out their exact location with the assistance of the Project Manager.
For payment purpose it will be considered onlythe trench dimensions indicated in the
drawing with exception to modifications requested by the Project Manager.Any
change from design must be approved before starting works.
Trench dimensions must be confirmed and sign-off by the Project Manager or his
representative before backfilling.
Before excavating on concrete or asphalt pavements, the edges of trenches must be
cut by a mechanical saw.
Temporary equipment must be installed for pedestrians or vehicles. Caution has to
be done to avoid flooding.
Contractor must prevent excavated material, silt or debris into the drainage system
located in roads and footways. Draining water fromgullies must not obstruct the
drainage system.
Building materials and/or waste from the excavation, deposited near the trench, must
be protected with wood board along the trench.
Contractor must evacuate excavated material, which is not suitable for backfilling,
with no additional charge.
Caution must be paid when excavation reaches the deep of 300 mm to avoid any
damaging on underground network.Excavation must be carried out by hand near the
underground facilities; machines could be used only on Project Manager or his
representative approval.
Trench shuttering must be used for the effective safety of people, protection of
nearby buildings and to avoid trench collapse, where necessary.
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2.3.1.2. Road crossing
It must be done with uPVC pipes embedded in reinforced concrete with ingredient
ratio of 1:3:5, making layers - width with 20 cm deep and 50 cm length on the
extremities.The total length of PVC pipes to be installed shall be calculated for the
road crossing with two reserve pipes. Details are shown on the drawings nº 0.0.21
For quotation purposes 3840 m of pipes shall be considered, becoming spares de
non used pipes.
Road occupation and period of work must be strictly followed for the trench crossing
road. Temporary traffic signs must be installed during all the work.
2.3.1.3. PVC pipe
Rigid uPVC pipes for cable protection, profiled to provide good mechanical protection
of buried cables, must be used.
The specification of the uPVC pipes shall be:
Final check by the Project Manager team is needed before backfilling. Otherwise, the
Employer could request to re-open up trench for checking. Contractor is responsible
for any delay due to this reason.
Standards ISO 4422-2
Diameter 110 mm
Wall thickness of pipe 5.30 mm.
Length 5.8 6.0 m.
Colour (Grey) Permanent non-fading, colour resistant to chemical
change.
Material Non-toxic and non-corrosive uPVC.
Not provide food source to micro/macro organisms
and fungi.
Resistance Resistant to chemical attack by a wide variety of
substances such as acids, alkalis and oils;
High resistant to fungus and bacterial attacks,
ultraviolet radiation, rain and atmospheric conditions.
Flammability Self-Extinguishing.
Hardness - Shore D 85 90
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2.3.1.4. Cable Installation, Trench Backfill and pavement
Unwinding of cables must be done with the drums placed on jacks or on
special racks by means of an steel axle
Rollers must be used to support cables.
Cables must be pushed slowly and progressively using traction means with
appropriate strength.
Sharp edge, such as pipe entrance, must be protected in order not to damage
the cable shielding during installation.
Three (3) meters surplus in cable end must be reserved for interconnection
and junction. Cable surplus in customer substations or primary substations or
poles must be confirmed with the Project Manager or his representative.
Bending radius during cable installation must be greater than 30D, which D is
the cable overall diameter, unless otherwise referred by the Project Manager
or his representative.
Bending radius after cable installed must be greater that 15D, which D is the
cable overall diameter, unless otherwise referred by the Project Manager or
his representative.
Cable installation must be done under authorization and supervision of the
Project Manager or his representative.
Cable must be laid on minimum of 100 mm thickness, of fine sand or fine
sifted soil, which fineness must be measured on a mesh of 1/16”
Cable ends must be sealed until the moment of assembling termination or
joint.
Cables in same circuit in a trefoil arrangement should be tied up by plastic ties
every 100 m. It must be left a gap of about 5 mmloosing in plastic tie, to avoid
cable injury.
Cables must be covered at least 200 mm thickness of fine sand or fine sifted
earth, which fineness on a wire mesh of 1/16”. The filling shall be made in
accordance with the drawings or as directed by the Project Manager or his
representative.
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Protection plates and warning tapes shall be installed as referred in the
drawings n. º 0.0.19 and 0.0.21.
Trench must only be backfilled after Project Manageror his representative
approval and with very fine soil.
Contractor must show soil samples for examination if requiredby the Project
Manager or his representative.Detail of sand information must be provided.
Complete backfill shall begin after cable testing with good condition.
Few compactions must be carried out during trench backfill with 200 mm
thickness of fine sand or sifted soil.
Compaction must be done by hand-rammer in the 200 mm layers on top of
cable.
Compaction on layer upper the signal plates could be done by hand-rammers
or vibration roller.
Compaction before paving could be done by hand-rammers or vibration roller.
If fine sand or sifted soil could only be used for trench backfill compaction
could be done in one time.
Contractor could only start the pavement works after approval by the Project
Manager or his representative.
New pavement must be the same quality as before, and whole length must be
uniform.
Concrete used in the paving, if any, must be in the ratio of 1:2:4, except
instructed by the Project Manager or his representative.
New pavement must be cleaned afterwards. If water is used for cleaning,
contractor should make sure no obstruction would make the drainage system
block.
Sand bags must cover live cables in trench. Contractor workers shall use
HV/MV Insulated Gloves when performing works near live cables.
Contractor should request thee Employer to shut down the corresponding set
of cable before re-locate MV cables as well as any cable junctions.
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2.3.1.5. Cable labelling
For MV cables identification anodized aluminium or laminated plastic are acceptable.
Labels with 100x30mm on each phase shall have inscribed in Portuguese Language
the cable number and phase designation (Cabo no. ......, Fase ......). Letters and
figures, in black colour, shall be of 5 mm high. Labels shall be fixed by plastic rivets.
2.4. CABLE ACCESSORIES
The Bidders are requested to supply, for the MV cables 70 mm2, 120mm2, 240mm2
and 500mm2, all the necessary junction boxes, including cable connectors, according
to the cable’s lengths above specified. Bidders shall pay attention to the bi-metallic
connectors, necessary,in some cases,for the junction between Copper and
Aluminium cables in the case of the a new single core XPLE Al 3x1x120 mm2 with an
existing single core XPLE 3x 1x50 mm2 Cu or in the case of a new single core XPLE
Al 3x1x240 mm2 with an existing single core XPLE 3x 1x95 mm2 Cu.
The cable junctions shall be the heat shrinkable type, recommended by the cable’s
maker and the supply shall include three spare kits of each type and cable size.
Location of the undergrounded cable junction must be indicated on the as built
documents. A special mark over the junction point has to be done on the pavement.
The contractor is also required to supply the terminations and connectors for all
cables in accordance to the type of MV switchgears proposed for the Distribution
Stations, Switching Stations or existents Secondary Substations, and in accordance
to the Ring Main Units proposed or existing in the secondary substations. In what
concerns the cable terminations to connect on the transformers MV bushings they
shall be pre-molded elbow or straight type, with separable dead-break connectors, 24
kV, 250A according to IEC 60 502-4.
For line feeder switchgear cable connection the elbow or straight typeconnectors
shall be 24 kV system voltages and 400 A continuous current.
The cable terminations supply shall include three spare kits of each type and cable
size.
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The wiring to perform the connection of the cable’s metallic screen to switchgears
earth bars, shall be done with 35 mm2 coppercable, 0.6/1kV, PVC insulated,
green/yellow colour and shall also be supplied the necessary connectors. To define
the total length it is necessary to consider that, in case of the switchgears where
toroidal CTs are requested for zero sequence protection, such earthing cable shall
cross the CT before to be earthed.
2.5. PLASTIC PROTECTION
Heavy duty cable protection covers, manufactured from high impact recycled
polyethylene sheet, 1000 x 300 x 12 mm, for mechanical protection of the buried
cables, shall be supplied. They shall be yellow colourand havethe inscription
“ELECTRA- Cabos de 20 kV – Perigo de Morte” The total length of the covers shall
be identical to the trenchtotal length,
Underground warning mesh, yellow colour, following BS EN 12613:2001, or
equivalent, shall also be supplied with 1.2 times the length of the trenches, to be
installed 20cm from the soil level along the trench. They shall have the inscription
“CUIDADO - CabosEléctricospordebaixo”
3. DISTRIBUTION STATIONS, SWITCHING STATIONS
AND SECONDARY SUBSTATIONS
3.1. PALMAREJO 20 KV SUBSTATION
3.1.1. General
A New Palmarejo20 kV Distribution Substation in a new40x12m2 building, equipped
with double bus bar switchgear for Physical separation between Generation and
Distribution Installations in Santiago System will be erected in a free area between
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northernborder of Palmarejo Power Station and the 20/60 kV Substation southern
border.
All the generator units, namely diesel Power Station, Solar Power Station, will keep
connected to the Main Palmarejo Power station Bus Bar and all the existing MV
network feeders including the 20/60 kV Substation feeder, will be transferred to the
new MV substation.
As a future most important distribution station for all Santiago Island Network it is
decided for the implementation of a double bus bar switchgear to decrease the risk of
general black-out in case of bus bar failure and in order to allow the maintenance
operation.
All the circuit breakers to be installed will be controlled by efficient protections units
and all the 20 kV system will be locally controlled and/or remotelyfrom scada control
center. All information, apparatus status and measures Voltage, intensity and KWh
will be transmitted to the control center and will be integrated in the future distribution
scada. Scan period will be 50 milliseconds.
The connection between the Power Plant bus bar and the new substation bus bar will
be made by five feeders with double aluminum cable 2x(3xLXHIV1x500) with 100
MVA total load capacity.
This scope of work includes the design of all building civil works,concrete trench civil
works for new cable installation and existing cable transfer, the furniture and
installation of the following metalclad cubicles and equipments:
4 Power Plant incoming feeder cubicles, rate current 1250 A
1 Outgoing 20/60 kV Substation feeder cubicles, rate current 1250 A
2 Outgoing 20/60 kV Substation feeder cubicles, rate current 630 A
9 outgoing network feeder cubicle, rate current 630 A
One measurement cubicle for both bus bar
One bus bar coupling 2500 A
One auxiliary transformer cubicle
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One 250 kVA 20/0,41 kV transformer
DC auxiliary pannels
AC Auxiliary panels for lighting and small power
The drawing 7.1.51 gives the Site Plan of the new substation
The drawing 7.0.07 gives the single line diagram of the new switchgear to install.
The Main LV switch board will be according to the drawing 0.1.36
The contractor has to take in consideration that Palmarejo power station will never be
shuted down and the energy outage in each feeder due to the works implementation,
especially for network feeder cables transfer, has to be reduced to the minimum as
possible.
3.1.2. Specifications of the new 20 kV switchgear
3.1.2.1. General
The 20 kV switchgear shall be metalcladtype, air insulated, double busbar type,
suitable for indoor installation, and shall be in accordance with IEC Standard
No.60298.The switchgear shall be in accordance with the single line diagram -
drawing no 7.0.07.
The new switchgear shall have the following main characteristics:
Rated Voltage : 24kV
Rated insulation level
Rated lightning impulse withstand
voltage to earth, between poles and
across open switching device : 125 kV (peak)
Across the isolating distance : 140 kV (peak)
Rated 1 min. power frequency withstand
voltage to earth, between poles and
across open switching device : 50 kV (rms)
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Across the isolating distance : 60 kV (rms)
Rated normal current of main circuits:
Busbar :2500A
Outgoing feeder panels :630A or 1250 A
Incoming feeder panels :1250 A
- Rated short time withstand current : 25 kA
- Rated duration of short circuit : 3 sec.
- Rated peak withstand current : 40 kA (peak)
Degree of protection
The external enclosure, with closed front doors, shall comply with no less
than IP4X, according to IEC Nº 60529
Internal partitions IP20 according to IEC standard No.60529
The equipment shall be dust-proof, rodent and insect proof. It shall be capable of
operating in tropical and humid conditions. Electric heaters, controlled by thermostat
and heater switch suitable for 220V-50Hz, shall be installed to prevent condensation,
particularly when the equipment is out of service.
Cast iron shall not be used for any part which may be subjected to mechanical shock.
Insulating materials shall have a high resistance to tracking.
The switchboards shall be suitable for mounting on the specified floor arrangement.
All necessary foundation or fixing bolts shall be provided for all circuits and for
specified spaces for future circuits and the cost included in the Tender Price.
All wiring compartments containing primary connections or equipment shall be
enclosed in metal conduit or equivalent.
Complete protection by covers and partitions shall be provided against approach to
live parts or contact with internal wiring parts to protection category IP 4X to IEC
60529. Interlock and safety equipment shall be provided to avoid any access to the
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live part of the cells or any wrong operation in any situation. The cubicles shall have
4 compartments segregated by metallic partition.
Withdrawable circuit breaker in a movable truck
Bus bar
Medium voltage cable connection
Low Voltage and protection equipment.
The circuit-breakers shall be mounted in moving portions with either horizontal or
vertical isolation from the fixed busbars and outgoing circuit connections.
The circuit-breakers shall be connected to the busbars and feeder circuit through
plug and socket type isolating devices. The devices shall be off load type but shall
be suitable for operation whilst the busbars or feeder circuits are live. It shall be
impossible to operate the isolating device if the circuit breaker is in the 'closed'
position. Withdrawal of a circuit breaker shall not be possible unless it is the open
position.
The main circuit isolating devices and all auxiliary circuit isolating devices shall be
self-aligning and accessible for maintenance. The main isolating contacts shall be
silver plated, self-cleaning and shall be mounted in porcelain or cast resin bushings.
The Withdrawable circuit breaker shall have 3 positions:
In service (connected)
In test
Withdrawn
Interlock shall forbid the circuit breaker moving from or in service when it is close.
Front doors must be lockable. Cubicles must be painted with an epoxy system dried
in oven or at least with an equivalent painting system. Colour must be approved.
The automatic shutters for the plug-in contact are to be permanently marked with
inscriptions "BARRAMENTO" to busbar side and "CABO" to cable side in the
incoming and outgoing feeder cubicles.
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Lighting feature 40W-220V-50Hz controlled by a door switch shall be installed inside
each low voltage compartment. At least 2NO+2NC Auxiliary contacts shall be
provided per cubicle for the remote signaling of the withdrawable circuit breaker
position.
All the cubicles shall be identified at front side and at rear side if they have rear
access for 20 kV cables connection, with approved labels engraved with the cubicles
number and the name of the feeder. Other labels can be required if necessary, as
well as a mimic diagram to be placed at the instrument chamber door. All the
equipment shall be labeled with the scheme reference and a functional reference.
Next to 20 kV cable connections points, inscriptions with the phase colour and
sequence (to be defined) shall be stated.
With the equipment for 20 kV switchgear, the contractor shall supply, in a suitable
padlocked box, one set of operation and maintenance devices including special tools.
3.1.2.2. 20 kV Circuit breakers
Three-pole, indoor, vacuum or SF6 type circuit breakers, in accordance with IEC
Standard No.60056 and with the following characteristics (others than those specified
in 22.1.2.1):
The circuit breakers shall comply with the requirements of IEC 62271-100 and IEC
62271-200
Rated short circuit breaking current : 25 kA (rms)
Rated normal current:
o Outgoing feeder panels : 630 or 1250 A
o Incoming feeder panels : 1250 A
Rated short circuit making current : 40 kA (peak)
Rated operating sequence: 0-3min.-CO-3min.-CO
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Operating mechanism:
The operating mechanism of the three poles of the circuit breaker shall be mechan-
ically coupled. An approved mechanically controlled indicator shall be provided to
show whether the circuit breaker is open or close and its closing spring is loaded or
unloaded.
The circuit breakers shall be provided with a manual operating closing/opening
device. Mechanical closing/opening device must be padlocked. When it is actuated,
circuit breaker close control must be inhibited.
The electrical tripping and closing of the circuit breakers shall operate between 70%
and 110% of the rated supply voltage of 110 Vdc.
A close and a trip push-buttons for mechanical control shall be provided for circuit
breakers.
After completed all closing operation, the spring shall be automatically reloaded. The
rated supply voltage for motor spring chargers shall be 110Vdc + 10% - 30%.
A mechanical operations counter shall be provided in the operating mechanism as
well as hand-crank for manual spring charge.
If SF6 type circuit breakers are proposed, 1 set of necessary equipment for refilling
and pressure testing shall be supplied by the contractor as well as a local supervision
and remote signal of SF6 pressure fault
The circuit breakers of same current rating shall be interchangeable and a suitable
interlock shall prevent the use of a circuit breaker with a current rating different of the
rating current of the cubicle.
The withdrawable circuit breaker can be locked by a padlock in the service position
and in the withdrawn position.
Spare auxiliary switches 2NO+2NC for circuit breaker open and spare auxiliary
switches 2NO+2NC for circuit breaker close shall be wired to the terminal blocks in
instrument compartment
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3.1.2.3. 20 kV Earthingswitch and voltage divisors
A fast-closing earthing switch of the output shall be provided and shall be
mechanically interlocked with the circuit breaker.The earthing switch can close when
the circuit breaker is fully withdrawn, and when the earthing switch is closed, the 20
kV circuit breaker cannot be moved in service position.
Rated current of the earthing switch
Short time (3 sec) withstand current is 16 kA (rms)
Rated short circuit making current is 40 kA (peak)
An approved mechanically operated indicator shall be provided to show whether the
fuse switch is open or close
The earthing switch shall have a mechanical hand control lockable with padlocks in
both positions - open and close - which shall be permanently marked with labels
"ABERTO” to open position and “LIGADO À TERRA” for close position.
A capacitor voltage divisor with a neon voltage indicator shall be provided on every
phase. The indicator shall indicate the presence of voltage in the three phases of the
cable side and shall be placed near the 20 kV earthing switch hand control or shall
be integrated in the mimic diagram.
3.1.2.4. 20 kV Current transformers
All current transformers shall be in accordance with IEC 60185.Secondary windings
of C.T. shall be earthed at one point only and the primary windings shall be capable
of carrying the rated primary current for a period of 1 minute with the secondary
winding circuit open. The output of each current transformer shall be calculated for
protection and control system. The contractor shall submit the calculations for
approval.
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3.1.2.5. 20 kV Voltage transformers
Each one of the incoming feeders shall have a set of 3 single phase voltage
transformers with two secondary cores, in accordance with IEC 60186, and with the
following characteristics:
Rated primary voltage : 20/3kV
Rated secondary voltage core No.1 : 110/3V
core No.2 : 110/3V
Rated secondary output core No.1 : 100VA
core No.2 : 60VA
Accuracy class: core No.1 : 0.5
core No.2 : 3
20 KV HRC fuses shall protect the voltage transformer.
A resistor with a convenient value, connected with the delta connection of the
secondary No.2must be used to inhibit ferro-resonances effects,
3.1.2.6. Instrument compartment equipment
Local control and protective relays shall be housed in the LV compartment of every
cubicle. All the facilities to allow future remote control and supervision from a PLC
system shall be provided.
The supply voltage for remote control shall be110V DC.
Control and protection polarity of each panel shall be switched by the respective
Local-Remote switch.
For each panel four independent power supplies shall be provided as specified
below:
110 V.d.c. for control and protection circuits;
110 V.d.c. or 24 Vd.c. for signaling circuits;
110 V.d.c. for circuit breaker motor spring loading;
220V-50Hz a.c. for heating and lighting;
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Suitable two poles mini circuit breakers shall protect every circuit of every cubicle.
They shall have 1NO+1NC auxiliary switch for the CB position "open" or "close".
The power shall be supplied directly, for each bus section, from dc and ac auxiliary
switchboards by four different two core cables and the wiring between the different
cubicles of each bus section shall be fully insulated.
A common supply and circuits for general alarms and supervision of control and
signaling supply fault shall be provided.
It shall also be provided all the equipment and wiring for the following systems:
- Interlocking;
- Control Voltage.
The protective relay and trip circuit supervision relays, actuators, the indicator
instrumentsalarm annunciators and the mimic diagram shall be on instrument
compartment door.
Semaphore position indicators for the earthing switches, discrepancy and control
switches for the 20 kV circuit breakers and neon voltage indicators, shall be on the
mimic diagram.
Local alarm annunciators shall be provided in transparent windows with suitable
inscriptions, steady illuminated by a lamp when the alarm or signal occurs and until to
be reset by local operator. Local reset push button, and remote resetting circuit by
future PLC system shall be provided per panel.
Colour code shall be used to discriminate every circuit 110 V DC, 24 V DC and AC.
Further to the before specified the minimum equipment to be installed in each panel
type, and the interlocking schemes and control expected shall be:
Outgoing Network Feeder Cubicles Nº 2,6,7,12,16 and18
1. One multifunctional meter to be able to measure and display the following
parameters:
active, reactive and apparent energy and power, three-phased on each phase,
import and export;
three-phased power factor on each phase;
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instantaneous U on each phase;
instantaneous I on each phase;
phase switch UU, UI and cosφ;
frequency;
succession of phases;
displays phase diagram P,Q;
The meters information shall be readable online through a dedicated
communications port in order to allow user to monitor and control energy
consumption, energy quality and service quality.
The meter have to be able to register and store all the information for a period not
less than 30 days and it has to be able to display maximum values..
2. The protective relays to be used shall be overcurrent and shortcircuit (50/51)
for the three phase’s protection and an earth-fault (50N/51N) element using
residual current arrangement from CTs phase´s or feed by a toroidal CT 100/1
A, around the three phase cables.
In the wiring coming from CTs, terminal blocks shall be inserted giving the
possibility to short circuit them and test the OC/EF relay. The trip order from
de OC/EF relay must be wired in such a way, it can be switched from the trip
coil of the circuit breaker to an external testing lamp.
Incoming feeder cubicles
interconnection with Palmarejo Power Plant:Feeder Cubicles Nº 4,9,14 and 17
interconnection with Gamboa Power Plant: Feeder Cubicles Nº 3,8 and 13
interconnection with 20/60 kV Substation: Feeder Cubicles Nº 5,10 and 15
1. One multifunctional meter to be able to measure and display the following
parameters:
active, reactive and apparent energy and power, three-phased on each phase,
import and export;
three-phased power factor on each phase;
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instantaneous U on each phase;
instantaneous I on each phase;
phase switch UU, UI and cosφ;
frequency;
succession of phases;
displays phase diagram P,Q;
The meters information shall be readable online through a dedicated
communications port in order to allow user to monitor and control energy
consumption, energy quality and service quality.
The meter have to be able to register and store all the information for a period not
less than 30 days and it has to be able to display maximum values..
2. One directional overcurrent and shortcircuit relay (67) and one directional
earth fault relay (67/N) for protection with convenient setting scales both for
currents and tripping times shall constitute the protection of these two feeders;
3. A set of undervoltage (27), overvoltage (59) underfrequency (81U)
overfrequency (81O) relay. The closing signal for the CB shall be controlled by
a convenient synchronising scheme. The incoming feeders from Palmarejo
Power Plant, Gamboa Power Plant and 20/60 kV Substation shall be operated
in parallel.
The protection CTs wiring must be done in such a way that in the future, after
an optical fibre cable be buried, it can be possible to introduce the longitudinal
differential relay (87L) already existing in Palmarejo S/S.
3.1.2.7. Earthing facilities and Earthing of metal parts
All metal parts including any relays, instruments, etc., mounted on the switchboard,
shall be connected to a copper earth bar, which runs along the full length of the
switchboard.
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The cross-section of the bar shall be sufficient to carry the rated short-time withstand
current of the switchgear for the time specified in the Schedule of Requirements.
The frame of the draw-out circuit-breakers shall be connected to the earth bar
through a substantial plug type contact arranged to make and maintain contact
before the main isolating contacts make.
The earthing function shall form part of the integral design of the equipment. Full
details of the method of earthing shall be submitted by the manufacturer. It shall not
be possible to select an integral earthing position, close an earth switch or connect a
portable earthing device unless the circuit-breaker is in the open position. When the
circuit-breaker is being used for earthing, a locking facility shall be provided to
prevent the breaker being opened by mechanical or electrical means. It shall be
impossible to return to the normal service position without first having removed this
locking facility.
3.1.3. MV/LV transformers
One three phase auxiliary transformer, suitable for indoor installation, shall be
provided to feed the a.c. auxiliary switchboard.The transformer shall have the
following characteristics:
Rated power : 100kVA or 250 KVA
Rated voltage ratio : 20.000/410-231V
Rated frequency : 50Hz
Method of cooling : ONAN
Impedance voltage at 75ºC and at principal tapping : 4%
Connection symbol : Dyn5
Tapping range : +5%, -5%
Tapping step : 2.5%
No. of tap positions : 5
Maximum short circuit level at HV terminals : 500MVA
Insulation level:
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- MV line terminal : LI 125 AC 50
- LV line terminal : AC 3
This transformer shall be oil immersed type with a no-load tap changer and it shall be
provided with the convenient fitting and own protective devices.
The high voltage and low voltage line terminals shall be fitted with cables
terminationsbox.
3.1.4. MV/LV transformers
As a Main LV Voltage switchboard, to supply the AC SB for all needs of the building
and the LV distribution network around installation a LVSB 1000 A type complying
the specifications on chapter 22.4.6.1 shall be installed.
3.1.5. AC and DC Auxiliary Voltages
One specific AC 220/380 V switchboard, to be located in the S/S the control room,
must be supplied from Main LV switchboard / auxiliary transformer. It must supply all
the AC consumers of the 20 kV Distribution Station, including the S/S lighting, and
supply also one rectifier able to feed one DC switchboard also dedicated to the S/S
DC consumers and charge one 110V dc alkaline battery to be located in special
room. Other battery and charger rated voltages can be offered depending on the
control equipment proposed control and monitoring scheme. The bidders shall
dimension those circuits and equipments taking in account an expansion of the
needs in 25%. The detailed design of the AC auxiliary SB shall be performed by the
contractor.
This rectifier 110V DC shall be suitable for a scheme of operation as following:
Normally the charger supplies an alkaline battery 110V DC and the
DCswitchboard of the substation.
When the General Circuit Breaker of DC switchboard is opened the charger
onlysupply the battery.
When AC supply to charger fails, its internal DC circuits and the DC
Switchboardwill be supplied by the battery.
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And for a mode of operation as following:
Normally the Charger will run at automatic control but shall be possible, to
selectto Manual control by a selector switch installed inside charger and
labeled withprecaution indications for manual use next to selector switch and
to thepotentiometer to regulate the output DC voltage in manual mode
operation.
At automatic operation it will be possible to select manually, both modes
ofautomatic operation: floating and equalizing.
Normally the charger will run at automatic floating operation supplying the
loadcurrent up to its rated current and the battery will supply eventual peaks.
If AC supply to charger fails for a time lag smaller than a time setted, when
theAC supply return, the charger shall continue at floating operation.
If AC supply 380/220V - 50Hz to charger fails for a time lag larger than a
timesetted, when the AC supply return, the charger shall automatically begins
atequalizing operation for a time proportional to the duration of AC supply fail.
UPS unit(s) must be supplied according to the proposed control scheme
consumption.
3.1.6. Earthing system
During the building works of the structures for equipment support and of the wire
mesh fences aclosed underground earthing system shall be established in order to
obtain a resistance less than 1(one) ohm.
The earthing system shall be designed, using closed rings of a convenient earthing
copper cable(with a cross section never less than 95mm2 in the main rings), buried 1
meter deep from soil surface level, in such away that each connection for metallic
structure or piece ofequipment could be connected to earth even if one leg of the ring
become damaged under thesoil.
The contractor shall also submit with the civil drawings of the building, the convenient
earthingsystem of the steel structures and its interconnections with the whole
earthing system of the S/S.
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No metallic parts, other than earthing system conductors and connectors can be
interposed in theearthing system circuits.
Inside the building the earthing net shall also be made in copper cable both for
connection of allthe metallic parts of the equipment and for connection of the auxiliary
transformer neutral point.
The zig-zag reactor neutral point must be earthed using an insulated LV,
unarmoured, coppercable with, at least 95mm2, and its connection to the earthing
system shall be made externally tothe building, on the underground earthing mesh,
inside a protected visit concrete box.
All the earthing system conductors shall be of electrolytic copper. Connectors and
devices forfixing Earthing System Conductors shall be made of copper alloy and all
the screws, nuts andwashers shall be in copper alloy or in stainless steel. Where
dissimilar metals are in connection,approved means shall be provided for prevent
electrochemical reaction and corrosion.
Connections shall be kept as short and straight and well tight as possible to avoid
increase theresistance of electric circuit and to be unaffected by vibrations.
3.1.7. Civil works
A new 40x12,5m2building shall be erected. It will be able to house at least25 MV
cubicles in one row and the following compartment:
One special room for the neutral reactance and the auxiliaries transformer to
be supplied, separated by a protection fence.
One control room will house all the all the LV switchgear including the DC
system except equipment for LV distribution.
Classical transformer substation (PT) will be built to house the transformer and
the LV distribution board. Transformer and LV board will be supplied and
installed and connected by the contractor. There is direct entrance to this room
and no common access with the 20 KV or 60 KV installations but an
emergency push-button for shut-down the 20 KV will be installed in the room.
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A meeting room about 50 m2 will be provided for commercial purpose.
Entrance shall be done from outside of the substation without any access to
the electrical installation.
A store room about 30 m2 will be provided.
For sanitary installation one set of porcelain or stainless W.C and hand-basin
will be provided for the commercial room. A 2m3 Water tank, piping and septic
tank shall be installed.
Building light and small power shall be installed by the contractor as follow:
The building shall have its own normal and emergency lighting systems in an
adequateillumination level for the different rooms. The contractor shall pay
particular attention to theillumination of the control room both in the front and
in the back of the panels and on theoperators control table.
Small power in all rooms shall also be installed in an adequate number of
units, prepared forconnection of mono and three phase tools.
One communication network shall also be installed for two incoming phone
lines, being bothdirectly connected to phones on the control table.
Air conditioning in MV Switchboard room and supervisor room.
The contractor has to submit forapproval the detailed design.
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3.2. GAMBOA 20 KV SUBSTATION
3.2.1. General
At the present moment Gamboa Substation is the main MV distribution station at
Praia Network. It is equipped with 25 years old, 20 kV switchgear, extended with 4
Normafix cells through two transition cubicles.
The scope of work in GamboaSubstation is considering the replacement of all
existing metalclad cubicles including the normafix ones by new ones. The furniture
includes:
3 Palmarejo SS incoming feeder cubicles, rate current 630 A
16 outgoing network feeder, rate current 630 A
Two measuring cubicle
One bus bar coupling 1250 A
One auxiliary transformer cubicle by circuit breaker 630 A
The Drawing 7.0.08 gives the single line diagram of existing switchgear and the
single line diagram of the new switchgear to install.
The drawing 7.1.52 gives the design of the existing building.
The contractor has to take in consideration that Gamboa is the most important
distribution station and it has to keep working while the rehabilitation is running so a
special plan and special installation has to be prepared for this purpose.
The contractor has also to transport the 4 last installed Normafix cubicles to Electra
storage at MonteBabosa.
3.2.2. Specifications of the new 20 kV switchgear
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3.2.2.1. General
The 20 kV switchgear shall be metalclad type, air insulated, single busbar type,
suitable for indoor installation, and shall be in accordance with IEC Standard
No.60298. The switchgear shall be assembled in accordance with the single line
diagram - drawing no. 7.0.08.
The new switchgear shall have the following main characteristics:
Rated Voltage : 24kV
Rated insulation level
Rated lightning impulse withstand
voltage to earth, between poles and
across open switching device : 125 kV (peak)
Across the isolating distance : 140 kV (peak)
Rated 1 min. power frequency withstand
voltage to earth, between poles and
across open switching device : 50 kV (rms)
Across the isolating distance : 60 kV (rms)
Rated normal current of main circuits:
Busbar : 1600A
Outgoing feeder panels : 630A
Incoming feeder panels : 630A
- Rated short time withstand current : 16 kA (rms)
- Rated duration of short circuit : 3 sec.
- Rated peak withstand current : 40 kA (peak)
Degree of protection
Enclosures with closed front doors: IP30 according to IEC No.60529
Internal partitions IP20 according to IEC standard No.60529
The cubicles shall have 4 compartments segregated by metallic partition
Withdrawable circuit breaker in a movable truck
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Bus bar
Medium voltage cable connection
Low Voltage and protection equipment.
Interlock and safety equipment shall be provided to avoid any access to the live part
of the cells or any wrong operation in any situation.
Withdrawable circuit breaker shall have 3 positions:
In service (connected)
In test
Withdrawn
Interlock shall forbid the circuit breaker moving from or in service when it is close.
Front doors must be lockable. Cubicles must be painted with an epoxy system dried
in oven or at least with an equivalent painting system. Colour must be approved.
The automatic shutters for the plug-in contact are to be permanently marked with
inscriptions "BARRAMENTO" to busbar side and "CABO" to cable side in the
incoming and outgoing feeder cubicles.
Earthing bar of every cubicle must be interconnected together.
Anti-condensation heaters shall be provided in each panel controlled by thermostat
and heater switch suitable for 220-50Hz.
Lighting feature 40W-220V-50Hz controlled by a door switch shall be installed inside
each low voltage compartment. At least 2NO+2NC Auxiliary contacts shall be
provided per cubicle for the remote signalling of the withdrawable circuit breaker
position.
All the cubicles shall be identified at front side and at rear side if they have rear
access for 20 kV cables connection, with approved labels engraved with the cubicles
number and the name of the feeder. Other labels can be required if necessary, as
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well as a mimic diagram to be placed at the instrument chamber door. All the
equipment shall be labelled with the scheme reference and a functional reference.
Next to 20 kV cable connections points, inscriptions with the phase colour and
sequence (to be defined) shall be stated.
With the equipment for 20 kV switchgear, the contractor shall supply, in a suitable
padlocked box, one set of operation and maintenance devices including special tools.
3.2.2.2. 20 kV Circuit breakers
Three-pole, indoor, vacuum or SF6 type circuit breakers, in accordance with IEC
Standard No.60056 and with the following characteristics (other than those specified
in 2.3.1.1):
Rated short circuit breaking current : 25 kA (rms)
Rated normal current:
o Outgoing feeder panels : 630A
o Incoming feeder panels : 630A
Rated short circuit making current : 40 kA (peak)
Rated operating sequence: 0-3min.-CO-3min.-CO
Operating mechanism:
The operating mechanism of the three poles of the circuit breaker shall be mechan-
ically coupled. An approved mechanically controlled indicator shall be provided to
show whether the circuit breaker is open or close and its closing spring is loaded or
unloaded.
The circuit breakers shall be provided with a manual operating closing/opening
device. Mechanical closing/opening device must be padlocked. When it is actuated,
circuit breaker close control must be inhibited.
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The electrical tripping and closing of the circuit breakers shall operate between 70%
and 110% of the rated supply voltage of 110 Vdc.
A close and a trip push-buttons for mechanical control shall be provided for circuit
breakers.
After completed all closing operation, the spring shall be automatically reloaded. The
rated supply voltage for motor spring chargers shall be 110Vdc + 10% - 30%.
A mechanical operations counter shall be provided in the operating mechanism as
well as hand-crank for manual spring charge.
If SF6 type circuit breakers are proposed, 1 set of necessary equipment for refilling
and pressure testing shall be supplied by the contractor as well as a local supervision
and remote signal of SF6 pressure fault
The circuit breakers of same current rating shall be interchangeable and a suitable
interlock shall prevent the use of a circuit breaker with a current rating different of the
rating current of the cubicle.
The withdrawable circuit breaker can be locked by a padlock in the service position
and in the withdrawn position.
Spare auxiliary switches 2NO+2NC for circuit breaker open and spare auxiliary
switches 2NO+2NC for circuit breaker close shall be wired to the terminal blocks in
instrument compartment
3.2.2.3. 20 kV Earthingswitch and voltage divisors
A fast-closing earthing switch of the output shall be provided and shall be
mechanically interlocked with the circuit breaker.The earthing switch can close when
the circuit breaker is fully withdrawn, and when the earthing switch is closed, the 20
kV circuit breaker cannot be moved in service position.
Rated current of the earthing switch
Short time (3 sec) withstand current is 16 kA (rms)
Rated short circuit making current is 40 kA (peak)
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An approved mechanically operated indicator shall be provided to show whether the
fuse switch is open or close
The earthing switch shall have a mechanical hand control lockable with padlocks in
both positions - open and close - which shall be permanently marked with labels
"ABERTO” to open position and “LIGADO À TERRA” for close position.
A capacitor voltage divisor with a neon voltage indicator shall be provided on every
phase. The indicator shall indicate the presence of voltage in the three phases of the
cable side and shall be placed near the 20 kV earthing switch hand control or shall
be integrated in the mimic diagram.
3.2.2.4. 20 kV Current transformers
All current transformers shall be in accordance with IEC 60185. Secondary windings
of C.T. shall be earthed at one point only and the primary windings shall be capable
of carrying the rated primary current for a period of 1 minute with the secondary
winding circuit open. The output of each current transformer shall be calculated for
protection and control system. The contractor shall submit the calculations for
approval.
3.2.2.5. 20 kV Voltage transformers
Each one of the 2 incoming feeders shall have a set of 3 single phase voltage
transformers with two secondary cores, in accordance with IEC 60186, and with the
following characteristics:
Rated primary voltage : 20/3kV
Rated secondary voltage core No.1 : 110/3V
core No.2 : 110/3V
Rated secondary output core No.1 : 100VA
core No.2 : 60VA
Accuracy class: core No.1 : 0.5
core No.2 : 3
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20 KV HRC fuses shall protect the voltage transformer.
A resistor with a convenient value, connected with the delta connection of the
secondary No.2 must be used to inhibit ferro-resonances effects,
3.2.2.6. Instrument compartment equipment
Local control and protective relays shall be housed in the LV compartment of every
cubicle. All the facilities to allow future remote control and supervision from a PLC
system shall be provided
The supply voltage for remote control shall be110V DC.
Control and protection polarity of each panel shall be switched by the respective
Local-Remote switch.
For each panel four independent power supplies shall be provided as specified
below:
110 V.d.c. for control and protection circuits;
110 V.d.c. or 24 Vd.c. for signalling circuits;
110 V.d.c. for circuit breaker motor spring loading;
220V-50Hz a.c. for heating and lighting;
Suitable two poles mini circuit breakers shall protect every circuit of every cubicle.
They shall have 1NO+1NC auxiliary switch for the CB position "open" or "close".
The power shall be supplied directly, for each bus section, from dc and ac auxiliary
switchboards by four different two core cables and the wiring between the different
cubicles of each bus section shall be fully insulated.
A common supply and circuits for general alarms and supervision of control and
signalling supply fault shall be provided.
It shall also be provided all the equipment and wiring for the following systems:
- Interlocking;
- Control Voltage.
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The protective relay and trip circuit supervision relays, actuators, the indicator
instrumentsalarm annunciators and the mimic diagram shall be on instrument
compartment door.
Semaphore position indicators for the earthing switches, discrepancy and control
switches for the 20 kV circuit breakers and neon voltage indicators, shall be on the
mimic diagram.
Local alarm annunciators shall be provided in transparent windows with suitable
inscriptions, steady illuminated by a lamp when the alarm or signal occurs and until to
be reset by local operator. Local reset push button, and remote resetting circuit by
future PLC system shall be provided per panel.
Colour code shall be used to discriminate every circuit 110 V DC, 24 V DC and AC.
Further to the before specified the minimum equipment to be installed in each panel
type, and the interlocking schemes and control expected shall be:
Outgoing Network FeederCubicles Nº 2,3,4,7,8,9,10,14,15,16,17,20,2 and 22
1. One multifunctional meter to be able to measure and display the following
parameters:
active, reactive and apparent energy and power, three-phased on each phase,
import and export;
three-phased power factor on each phase;
instantaneous U on each phase;
instantaneous I on each phase;
phase switch UU, UI and cosφ;
frequency;
succession of phases;
The meters information shall be readable online through a dedicated
communications port in order to allow user to monitor and control energy
consumption, energy quality and service quality.
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The meter have to be able to register and store all the information for a period not
less than 30 days and it has to be able to display maximum values..
2. The protective relays to be used shall be overcurrent and shortcircuit (50/51)
for the three phase’s protection and an earth-fault (50N/51N) element using
residual current arrangement from CTs phase´s or feed by a toroidal CT 100/1
A, around the three phase cables.
In the wiring coming from CTs, terminal blocks shall be inserted giving the
possibility to short circuit them and test the OC/EF relay. The trip order from
de OC/EF relay must be wired in such a way, it can be switched from the trip
coil of the circuit breaker to an external testing lamp.
Incoming feeder cubicles
Interconnection with PalmarejoDistribution Station:Feeder Cubicles Nº 6,11 and
18
Interconnection with São Filipe 60/20 kV Substation:Feeder Cubicles Nº 5 and
19
1. One multifunctional meter to be able to measure and display the following
parameters:
active, reactive and apparent energy and power, three-phased on each phase,
import and export;
three-phased power factor on each phase;
instantaneous U on each phase;
instantaneous I on each phase;
phase switch UU, UI and cosφ;
frequency;
succession of phases;
The meters information shall be readable online through a dedicated
communications port in order to allow user to monitor and control energy
consumption, energy quality and service quality.
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The meter have to be able to register and store all the information for a period not
less than 30 days and it has to be able to display maximum values.
2. One directional overcurrent and short-circuit relay (67) and one directional
earth fault relay (67/N) for protection with convenient setting scales both for
currents and tripping times shall constitute the protection of these two feeders;
3. A set of under voltage (27), overvoltage (59) under frequency (81U) over
frequency (81O) relay. The closing signal for the CB shall be controlled by a
convenient synchronizing scheme. The incoming feeders from Palmarejo
Power Plant, Gamboa Power Plant and 20/60 kV Substation shall be operated
in parallel.
The protection CTs wiring must be done in such a way that, after dismantling
the existing MV equipment, the contractor can transfer three sets of already
existing longitudinal differential relay (87L)from the incoming Palmarejo Power
Plant cubicle to the new cubicles.
3.2.2.7. Earthing facilities and Earthing of metal parts
All metal parts including any relays, instruments, etc., mounted on the switchboard,
shall be connected to a copper earth bar, which runs along the full length of the
switchboard.
The cross-section of the bar shall be sufficient to carry the rated short-time withstand
current of the switchgear for the time specified in the Schedule of Requirements.
The frame of the draw-out circuit-breakers shall be connected to the earth bar
through a substantial plug type contact arranged to make and maintain contact
before the main isolating contacts make.
The earthing function shall form part of the integral design of the equipment. Full
details of the method of earthing shall be submitted by the manufacturer. It shall not
be possible to select an integral earthing position, close an earth switch or connect a
portable earthing device unless the circuit-breaker is in the open position. When the
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circuit-breaker is being used for earthing, a locking facility shall be provided to
prevent the breaker being opened by mechanical or electrical means. It shall be
impossible to return to the normal service position without first having removed this
locking facility.
3.2.3. Earthing system
The Contractor shall earthall thesupplied and existent equipment.
The existing underground earthing system shall be improved in order to obtain a
resistance less than 1(one) ohm. All metallic parts of the building shall be earthed.
No metallic parts, other than earthing system conductors and connectors can be
interposed in theearthing system circuits.
Inside the building basement a new earthing net shall also be made in copper cable
with, at least 95mm2, for connection of allthe metallic parts of the equipment.
All the earthing system conductors shall be of electrolytic copper. Connectors and
devices forfixing Earthing System Conductors shall be made of copper alloy and all
the screws, nuts andwashers shall be in copper alloy or in stainless steel. Where
dissimilar metals are in connection,approved means shall be provided for prevent
electrochemical reaction and corrosion.
Connections shall be kept as short and straight and well tight as possible to avoid
increase theresistance of electric circuit and to be unaffected by vibrations.
3.2.4. Power cable and control cable arrangement
The Contractor shall supply and install all necessary equipments, namely metallic
cable ladder and accessories to provide a new arrangement for the existing MV
power cables in the substation basement - cable galleries and the control cables
according to the good practice.
3.2.5. Civil works
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Some improvement shall be made inside the building - first floor and basement -
namely new painting and wall treatment, water proofing of the basement and the
roof, installation of insulated floor, access to the basement, doors replacement,
lighting and small power installation upgrade, ventilation and air conditioning.
3.3. SWITCHING STATIONS
3.3.1. General
To fulfil the objective of this project, the following must be done:
In Santiago Island
1. Achada Grande Switching Station -(Single line diagram drawing number
7.1.17)
Erection of new 8x5 m2 building according to the drawings nº 0.0.09/10/11/12
Supply and installation of
All MV switchgear equipment
1 MV/LV transformer
1 LV Fuses Board
1 Rectifier/ Batteries/DC switchboard
Light and small power plugs
Earthing circuit
Safety equipment
In Fogo Island
1. Patim Switching Station – (Single line diagram drawing number 8.1.08)
Erection of new 6x4 m2 building according to the drawings nº 0.0.05/06/07/08
Supply and installation of
All MV switchgear equipment
1 MV/LV transformer
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1 LV Fuses Board
1 Rectifier/ Batteries/DC switchboard
Light and small power plugs
Earthing circuit
Safety equipment
2. Ponta Verde Switching Station – (Single line diagram drawing number
8.1.09)
Erection of new 6x4 m2 building according to the drawings nº 0.0.05/06/07/08
Supply and installation of
All MV switchgear equipment
1 MV/LV transformer
1 LV Fuses Board
1 Rectifier/ Batteries/DC switchboard
Light and small power plugs
Earthing circuit
Safety equipment
3. Xaguate Switching Station – (Single line diagram drawing number 8.1.10)
Full rehabilitation of the existing building with new 4x4 m2 building according
to the drawings nº 0.0.01/02
Supply and installation of
All MV switchgear equipment
1 MV/LV transformer
1 LV Fuses Board
Light and small power plugs
Earthing circuit
Safety equipment
4. CovaFigueira Switching Station – (Single line diagram drawing number
8.1.11)
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Partial rehabilitation of existing building
Supply and installation of
MV equipment for extension of existing switchgear
Light and small power plugs
Earthing circuit
Safety equipment
In MaioIsland
1. Morro Switching Station - (Single line diagram drawing number 6.1.17)
Erection of new 6x4 m2 building according to the drawings nº 0.0.05/06/07/08
Supply and installation of
All MV switchgear equipment
1 MV/LV transformer
1 LV Fuses Board
1 Rectifier/ Batteries/DC switchboard
Light and small power plugs
Earthing circuit
Safety equipment
2. Pedro Vaz Switching Station -(Single line diagram drawing number 6.1.18)
Improvement of existing building
Supply and installation of
All MV switchgear equipment
1 Rectifier/ Batteries/DC switchboard
Light and small power plugs
Earthing circuit
Safety equipment
3. Curralona Switching Station - (Single line diagram drawing number 6.1.16)
Erection of new 4x4 m2 building according to the drawings nº 0.0.01/02.
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Supply and installation of
All MV switchgear equipment
1 MV/LV transformer
1 LV Fuses Board
Light and small power plugs
Earthing circuit
Safety equipment
3.3.2. Existing MV switchgear
Today, ELECTRA is using, for this type of application, one modular, air insulated
switchgear, following IEC 60298 and IEC 60129, with the following main data:
Rated Voltage: 24 kV
Insulation level:
- PF (50Hz/1min): 50 kV (rms)
- LI (1.2/50μs) : 125 kV (peak)
Busbar rated current: 630 A
Rated short time withstand current: 16 kA, 3” (rms):
Rated peak withstand current: 40 kA (peak)
Degree of protection:
- MV compartment: IP 65
- Mechanism compartment: IP2XC
- Busbar, cable and fuse compartments: IP3X
3.3.3. The MV cubicle to supply and install
3.3.3.1. General
The system shall be composed of a set of reduced size modular cubicles, single or
multifunctional, for different 24 kV power distribution configurations.
The following main features shall be guaranteed:
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The cubicles shall be full SF6 gas-insulation, providing protection against
harsh environmental elements(including flooding), long service life and
maintenance-free of life parts.
Full modularity and future extendibility in both sides using special plug in
connecting sets;
Internal arcs withstanding for personal protection, in accordance with IEC
60298
Small dimension and low weights for easier handling and installation
Simple and safe operation
The metal enclosure of the cubicles shall be made of galvanized steel plate,
an shall be sturdy enough to prevent deformation and ensure protection under
the expected operation condition.
The cable connectionsup to 240 mm2 shall be with Bushing / plug in IEC type
terminals according to EN 50181 up to 200 A and up to 400 A.
The front cover of each cubicles shall be properly interlocked to provide safe,
convenient access to the cable terminals and fuse holder
Each cubicle shall be equipped with a device witch continually will indicate
voltage presence in the equipment
Every cubicle shall have:
a separate low voltage compartment, closed by a door, where the control and
protection equipment shall be installed.
an heating resistance 220V- 50 Hz and controlled by thermostat in the MV
compartment and LV compartment.
The following standards shall be applied:
IEC 20298 - Metal enclosed switchgear for alternative current rated voltage
over 1 kV and under 52 kV
IEC 60265 - High voltage switches for rated voltage over 1 kV and under 52
kV
IEC 60129 - Alternating current disconnectors and earthingdisconnectors
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IEC 62271 - 105 Alternating current switch-fuse combination
IEC 62271-100 High voltage alternating current circuit breakesr.
3.3.3.2. Circuit breaker protection functional feeder cubicle.
Equipped with
Vacuum circuit breakers (IEC 60056):
Rated voltage 24 kV
Rated current incoming feeder an bus bar: 630 A
Breaking capacity: 16 kA (rms)
Making capacity: 40 kA (peak)
Rated operating sequence: 0-3min-CO-3min-CO
The circuit breakers shall be provided with manual close/open device. One electrical
tripping device and one electrical close device shall operate between the limits of
70% and 110% of the rated supply voltage of 24 V dc. One manual close and one
manual trip push-buttons shall be provided. After the closing operation, the spring
shall be automatically loaded. The rated voltage for spring motors shall be 24 V dc.
Mechanical operations counter shall be provided on each circuit breaker. Two hand
cranks, for manual spring charge shall be provided per station or one hand cranks for
manual spring shall be provided per circuit breaker.
SF6 busbarswitch (IEC60129),
630 A, 16 kA (rms) 40 kA (peak), manually controlled and duly interlocked with the
circuit breakers and with the earthing switch. Such switch shall be lockable by
padlock both in open and in closed position.
Current transformers (IEC60185):
Rated primary current: 50-100 A or 150-300
Rated secondary current: 5 A / 5 A
Accuracy class: 5 P15
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Rated output: in accordance with the
protection relays and used
wiring.
Secondary windings of each CT shall be earthed at one point only and the primary
winding will be capable of carrying the rated primary current for a period of one
minute with the secondary open circuited.
Feeder earthing switch (IEC 60129):
Rated short circuit making current: 40 kA peak
Manual control interlocked with the busbar switch. The earthing switch shall be
lockable both in open and closed position by padlocks.
Voltage divisors
Associated with low voltage capacitors and with neon voltage indicators for signaling
cable voltage presence in the three phases.
Control and protection scheme:
Each cubicle shall have a separate low voltage compartment where the local control
and protection equipment shall be installed: terminal blocks, micro circuit breakers,
protection for motor spring charge, control, protection and an OC/EF relay. All the
facilities to allow future remote control and supervision from a PLC system shall be
provided.
The protective relays shall be:
An overcurrent and shortcircuit (50/51) for the three phase’s protection
an earth-fault (50N/51N) using residual current arrangement from CTs phase´s
or feed by a toroidal CT 100/1 A, around the three outgoing cables.
Terminal blocks shall be inserted in the wiring from CTs for the purpose of short-
circuit and the test of the OC/EF relay.
The trip order from de OC/EF relay can be switched from the trip coil of the circuit
breaker to an external testing lamp.
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Each LV compartment shall be equipped with a multifunctional energy analyzer for
voltage, current, energy, power, frequency and power factor measuring.
Lighting feature 40W-220V-50Hz controlled by a door switch shall be installed inside
each low voltage compartment.
Labelling:
The cubicles shall be identified with labels 60 x 120 written in Portuguese language
with the designation of the S/S where the feeder is connected and the cable number.
The open and close position of the circuit breaker shall also be labelled with the
words ABERTO and FECHADO.
The earthing switch hand control shall also be labelled with ABERTO and LIGADO À
TERRA for open and earthed respectively.
3.3.3.3. Load break switch feeder cubicle.
Equipped with
SF6 busbar load break switch (IEC 60129)
630 A, 16 kA(rms) 40 kA (peak),
Manual controlled and interlocked with the earthing switch.
Such switch shall be lockable by padlock in open and in closed position.
Cable earthing switch (IEC 60129):
Rated short circuit making current: 40 kA peak
Manual controlled and interlocked with the busbar disconnector.
The earthing switch shall be lockable both in open and closed position by padlocks.
Voltage divisors
Associated with low voltage capacitors and with neon voltage indicators for signaling
cable voltage presence in the three phases.
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Labelling
The cubicles shall be identified with labels 60 x 120 written in Portuguese language
with the designation of the S/S where the feeder is connected and the cable number.
The earthing switches control shall also be labelled with ABERTO and LIGADO À
TERRA for open and earthed respectively.
3.3.3.4. Transformer feeder cubicles
Equipped with
SF6 load break switch - fuse combination,
630 A, 16 kA (rms) 40 kA (peak), manually controlled and interlocked with an
earthing switch located downstream
The fuses must be 20 A, 25 Aor 40 A (IEC 60282.1, IEC60420). The blow up of one
fuse must trip the three phases of the load break switch.
The switch shall be lockable by padlock both in open and in closed position.
The cubicle shall be equipped by a 220 Vac trip coil to allow the switch disconnector
to be automatically opened by an external signal, such as one sent by the
transformer thermostat in case of overheating.
Voltage divisors
Associated with low voltage capacitors and with neon voltage indicators for signalling
cable voltage presence in the three phases.
Labelling
The cubicles shall be identified with labels 60 x 120 written in Portuguese language
with the designation of the transformer, when more than one in the S/S or just
TRANSFORMADOR when only one in the S/S. The earthing switches hand control
shall also be labelled with ABERTO and LIGADO À TERRA for open and earthed
respectively.
3.3.3.5. Bus bar coupling cubicles
Equipped with
SF6 busbar load break switch (IEC60129)
630 A, 16 kA (rms) 40 kA (peak), manually controlled.
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Such switch shall be lockable by padlock both in open and in closed position.
3.3.3.6. Measuring cubicles
Equipped with a set of 3 single phase voltage transformers in accordance with IEC
60186, and with the following characteristics:
Rated primary voltage : 20/3kV
Rated secondary voltage : 110/3V
Rated secondary output : 100VA
Accuracy class: : 0.5
20 KV HRC fuses shall protect the voltage transformer.
A resistor with a convenient value, connected with the delta connection of the
secondary No.2 must be used to inhibitferro-resonances effects.
3.3.4. MV/LV Power Distribution Transformers
One MV/LV indoor transformerfor each S/S, oil immersed type, hermetically sealed,
with the following characteristics in accordance to IEC 60076:
Rated power : 250 or 400 KVA
Rated voltage ratio : 20.000-15000/410-236V
Rated frequency : 50Hz
Method of cooling : ONAN
Impedance voltage at 75ºC and at principal tapping : 4%
Connection symbol : Dyn11
Tapping range : +5%, -5%
Tapping step : 2.5%
No. of tap positions : 5
Maximum short circuit level at HV terminals : 500MVA
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Insulation level:
- MV line terminal : LI 125 AC 50
- LV line terminal : AC 3
Maxaccepted load losses at rated power: **** W
Max accepted no load losses: **** W
Max accepted noise level: 58 dB
Painting: grey colour, RAL 7033
The transformers shall be provided with:
the convenient fittings and its own protective devices which trip the CB : at
least one thermometer with maximum indicator and an oil level indicator
plug-in bushings on MV side
4 LV flag lugs and a metallic LV cable box for cables coming from the left
or/and the right side of the transformer.
A switch for the MV voltage 15 KV/ 20 KV: controlled externally without
dismantling or removing anything.
A tap changer ± 2 x 2.5%controlled externally without dismantling or removing
anything
3.3.5. LV distribution Fuse Boards
One low voltage distribution fuse boards shall be installed in every substation.
The LV distribution fuse board is designed for 630 kVA transformers.
The general one line diagram is the represented in drawing no.01/28-4 and the
construction drawing are no. 01/28-5.
It shall include also the Public Lighting control and protection system and one photo-
electric cell to be installed outdoor of the PT and the VV 2x1.5 mm2 cable to connect
it to the fuse board.
3.3.6. AC Panel Board
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An AC panelboard shall be provided and installed inside the building on the wall near
the door. The panel shall be energized by theLV network by Electra and shall supply
power to the AC auxiliaries of the station The AC panelboard shall house:
A head differential Circuit Breaker 300milliamperes
The feeder micro circuit breakers for every electrical equipment
2 spares micro circuit breakers
Spare room for 6 future micro circuit breakers
Circuit breaker is magnetic-thermic type with opening/closing of the phase and of the
neutral.
3.3.7. Rectifier / Battery / DC Switchboard
A metallic cubicle housing the rectifier, the batteries and the DC switchboard shall be
provided and installed. It shall be energized from the AC panel board and generate
the 24V DC for the equipment of the switching station.
The cubicle shall have a protection IP 20 and shall be painted with an epoxy system
similar to the other cubicle. Cautions shall be taken to avoid overheating of the indoor
equipment. It shall have 2 compartments, each one close by a front door lockable
with a triangle key; the lowest compartment shall house the battery.
Two rectifiers in parallel shall be in the top compartment
Each one is:
Protected by a magneto thermic circuit breaker on the AC circuit
Capable
o to supply energy 24V DC to the entire substation and load batteries
from 0 to full load in less than 12 hours
o to maintain the DC at 24 V ± 10% with the AC supply
and have on the front door (at least):
a green led signalling the rectifier in service
a red led signalling the rectifier in fault
a red led signalling the AC supply missing
a red led signalling battery fuses blow up (or battery CB open)
Indication of the DC voltage
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The circuit breakers to protect the DC circuits shall be housed in the top
compartment. They are calibrated by the contractor in accordance with the
equipment supplied. 2 spare circuit breakers shall be installed. All the interconnection
with external equipment shall be done on a terminal block. DC circuit and AC circuit
shall be segregated and must follow a colour code.
Batteries Nickel –Cadmium shall be housed in the bottom compartment. Capacity
must be calculated for three O/C sequences of the 20 kV circuit breakers and keep
all the control system in service during 6 hours without AC power. Protective device
(fuse or CB) shall protect the battery from any over current.
3.3.8. Lighting and Small Power
Shall be supplied and installed:
two 40 W fluorescent lamps
two a.c. 230V-50 Hz, (1ph + N + E), 25 A, IP 67, sockets
one emergency lighting block above the door. The block has its own battery
and its switch on automatically in case of AC outage. Capacity shall be for 2
hours without AC power.
The VV connection with the AC panelboard.
3.3.9. Earthing System
The protection earthing system is separated from the neutral earthing circuit and for
both the earthing resistance shall be lower than 10 Ohms. The distance between any
buried parts of the two systems cannot be less than 20 meters
The standard earthing electrodes are electrolytic copper plates (1000x500x2.5mm)
installed vertically, being the largest side horizontally located at 1 meter depth from
soil surface. However earthing rods installed vertically, with the head at 1m depth,
and paralleled with main electrode, can also be used in order to reduce earthing
resistance.
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3.3.9.1. Protection Earthing System
A ring of non insulated 50 mm2 copper conductor shall be buried at 1m deep all
around the building and at 80 cm from the foundation. All the protective earthing
rods shall be connected to this buried ring by a 50 mm2 conductor. The metallic
structure of the building shall be also connected to the buried ring at least in two
opposite location. The connections shall be made by welding process or by effective
crimping process using cooper C connectors and adequate tools.
A loop of the buried circuit is connected to a disconnectable connector (for earthing
metering purposes) located on the wall inside the building near the door.
From this connector, a ring of a copper conductor 50mm2 shall be installed on the
wall inside the building. A 35mm2 copper conductor shall earth all the main
equipment and metallic parts of the building. Transformer tank, cover and cable box,
LV Distribution fuse board, MV RMU shall be connected at least at two opposite
points.
Flexible copper conductors 16 mm2 shall interconnect the door frame and the door
with a loop large enough to avoid breakage.
Reinforcement steel embedded in the floor must be also earthed by a 35 mm2
copper conductor.
3.3.9.2. Transformer neutral Earthing System
One or more earthing electrodes must be connected directly to one disconnectable
connector (for metering purposes) by insulated copper cable of 50mm2, 0.6/1kV, VV,
which external sheath shall be black colour and the internal sheath shall be blue
colour.
The connecting cable must be buried 1 m deep and be mechanically protected by
auPVC pipe of small diameter and strong wall.
Transformer Neutral shall be connected to the disconnectable by an insulatedcopper
cable of 50mm2, 0.6/1kV, VV
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3.3.10. Safety Equipment
In each switching station it shall be installed:
One wall board with instructions for first help, written in Portuguese language,
to be observed in case of electrocuted people.
One set of rubber gloves duly insulated for 24 kV;
One insulated platform for 24 kV;
3.3.11. Civil Works
3.3.11.1. Erection of New Buildings
The buildings should be able to house all the specified equipments and have some
space for future expansion. For different switching stationsthe buildings are differently
sized, 4x4m2 or4x6m2 or 5x8m2 and the guide designs are presented in the
drawings 0.0.01/02, 0.00.05/06/07/08, 0.0.09/10/11/12. The contractors are
requested to revise and to present their own best proposal according to the definitive
site plan and to submit for approval.
Metallic ventilation louvers, doors and trench covers must be hot deep galvanized.
The contractor has to submit for final approval the detailed.
3.3.11.2. Preparatory and Erection Works of MV and MV/LV installations were
existing buildings need rehabilitation
For the switching stations to be rehabilitated the contractor shallinstall outside, near
the existing stations, temporary safe containerized switching stations to where the
existing MV and LV cables will be transferred during the works. Once the works are
finalized and the equipment tested, the MV and LV cables shall be transferred to the
rehabilitated station.
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Bidders are requested to propose a comprehensive description about the way they
plan to do these works and the time schedule. Bidders shall include in their price the
temporary use of the necessary equipment for this type of solution. Bidders may also
propose alternative solutions. The cable’s transfer will be made by the contractor in
closed cooperation with ELECTRA staff.
The dismounting of the existing equipment and its transportation to ELECTRA Stores
are included in the contractor scope of works.
3.4. MV/LV SECONDARY SUBSTATIONS
In Portuguese language secondary substations are normally called Postos de
Transformação or PTs and we will use also this name in the specification. For the
new PTs it will be necessary to supply the equipment and build new buildings to
install the equipment.Some PTs needs to be rehabilitated or upgraded to 20 kV by
replacement of MV switchboard or distribution transformer or both of them. The civil
rehabilitation of the buildings is also considerate. To fulfil the objective of this project,
the following must be done:
In Santiago Island
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In FogoIsland
In MaioIsland
3.4.1. General
The MV/LV secondary substation is composed by:
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one ring main unit with two line feeder and one transformer feeder or one unit
with one line feeder and one transformer feeder.
one transformer with a rated power of 160, 250, 400 or 630 kVA;
one LV distribution fuse board, sized for 250 A (160kVA transformers) or 1000
A (630 kVA transformers, with 6 fuses tri-blocks for outgoing LV cables and
incorporating also two three phase (six single phase) public lighting outgoing
protection fuse bases.
one lighting and small power switchboard
The single line diagram of the ring main units is represented in drawing no. 0.1.28
The secondary substation building design,including the equipment layout in the
building, the earthing circuit, the lighting and small power system installation shall be
standardized for two models depending on the municipal authorities site implant
definitions:
4x4 square type represented in the drawing no. 0.0.01/02
Hexagonal type represented in the drawing no. 0.0.03/04
The metallic ventilation louvers, the door and the trench covers details are
represented in the drawing no. 0.0.18.
The LV fuse board and equipment disposition is represented in drawing 0.1.35 for
250 A (transformer up to 160 kVA) and 0.0.36 for 1000 A (transformer 250 up to 630
kVA).
3.4.2. MV Switchgear Specification
3.4.2.1. General
The system shall be composed of a set of reduced size modular cubicles, single or
multifunctional, for different 24 kV power distribution configurations.
The following main features shall be respected:
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The cubicles shall be full SF6 gas-insulation, providing protection against
harsh environmental elements (including flooding), long service life and
maintenance-free of life parts.
Full modularity and future extendibility in both sides using special plug in
connecting sets;
Internal arcs withstanding for personal protection, in accordance with IEC
60298
Small dimension and low weights for easier handling and installation
Simple and safe operation
The metal enclosure of the cubicles shall be made of galvanized steel plate,
an shall be sturdy enough to prevent deformation and ensure protection under
the expected operation condition.
The cable connections up to 240 mm2 shall be with Bushing / plug in IEC type
terminals according to EN 50181 up to 200 A and up to 400 A.
The front cover of each cubicles shall be properly interlocked to provide safe,
convenient access to the cable terminals and fuse holder
Each cubicle shall be equipped with a device witch continually will indicate
voltage presence in the equipment
Every cubicle shall have:
a separate low voltage compartment, closed by a door, where the control and
protection equipment shall be installed.
an heating resistance 220V- 50 Hz and controlled by thermostat in the MV
compartment and LV compartment.
The following standards shall be applied:
IEC 20298 - Metal enclosed switchgear for alternative current rated voltage
over 1 kV and under 52 kV
IEC 60265 - High voltage switches for rated voltage over 1 kV and under 52
kV
IEC 60129 - Alternating current disconnectors and earthingdisconnectors
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IEC 62271 - 105 Alternating current switch-fuse combination
IEC 62271-100 High voltage alternating current circuit breakesr.
The main electrical characteristics of the Ring main Units are:
Rated Voltage: 24 kV
Insulation level:
- PF (50Hz/1min) : 50 kV (rms)
- LI (1.2/50μs) : 125 kV (peak)
Busbar rated current : 630 A
Rated short time (3 sec) withstand current : 16 kA, (rms):
Rated peak withstand current : 40 kA (peak)
3.4.2.2. Equipment for line feeders function
SF6 busbar load break switch (IEC60129), 630 A, 16 kA(rms) 40 kA (peak),
manually controlled and mechanically interlocked with the earthing switch. It shall be
lockable by padlock both in open and in closed position.
Feeder earthing switch (IEC 60129):
Rated short time (3 sec) current 16 kA (rms)
Rated short circuit making current: 40 kA peak
Feeder earthing switch (IEC 60129):
Rated short circuit making current: 40 kA peak
Mechanically interlocked with the busbar switch.
Lockable by padlocks in both position open and close.
Capacitor Voltage divisors
They are connected on the 3 phases with neon indicators for signaling voltage
presence in the three phases.
Labeling: The cubicles shall be identified with labels 60 x 120 written in Portuguese
language with the designation of the S/S where the feeder is connected and the
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cable number. The earthing switches shall also be labelled with ABERTO and
LIGADO À TERRA for open and earthed respectively.
3.4.2.3. Equipment on transformer protection cubicles:
SF6 load break fuse-switch, 200 A, 16 kA (rms) 40 kA (peak), manually controlled
and mechanically interlocked with an earthing switch located downstream the fuses.
The fuse’s rating must be 20 A, 25 A or 40 A (IEC 60282.1, IEC 60420) when the
transformer’s rated power is respectively 250, 400 or 630 kVA,.
The fusion of one fuse must trip the three phases of the switch. The switch shall be
lockable by padlock in both position open and close.
Earthing switch (IEC 60129):
Rated short circuit making current: 40 kA peak
Mechanically interlocked with the busbar switch.
Lockable by padlocks in both position open and close.
Voltage divisors associated with low voltage capacitors and with neon voltage
indicators for signaling cable voltage presence in the three phases.
Labeling: The cubicles shall be identified with labels 60 x 120 written in Portuguese
language with the designation of the transformer, when there is more than one in the
S/S or just TRANSFORMADOR when only one in the S/S. The earthing switches
shall also be labelled with ABERTO and LIGADO À TERRA respectively for open and
close position.
3.4.3. Directional Fault Current Indicator for Uderground Network
Each new secondary substation, installed in a masonry building or in a PUC,as well
as those to be rehabilitated shall be equipped with a self poweredintelligent
directional fault-current indicator for 10-24kv underground cable networks, located in
one of the ring cables.
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The cable fault indicator shall be able to locate short-circuit /Phase To Phase (PTP)-
and earth faults/PhaseTo Earth (PTG) in underground cable distribution networks,
with isolated or impedance earthed neutral.
The indicators shall be placed at substations, Ring Main Units or any installation
where exists a cable termination and access to capacitive test points for measuring
the phase voltage.
Upon detecting a fault in the cable, the indicator gives off an intermittent red or green
light-flash (LED). One LED flashing indicating an earth-fault and both LED flashing
indicating a short-circuit fault. External indication units for mounting outside the
station over the door of the building shall be supplied. The colours of the LED will
also indicate direction to the fault location for earth-faults with reference to the busbar
where the indicator is situated.
The line fault indicator shall be equipped with an internal relay-card, giving the
possibility for connection to the communication devices for the following four different
relay-output’s to an RTU:
Transient Fault in red direction
Transient Fault in green direction
Permanent Fault in red direction
Permanent Fault in green direction
The housing of external indicator shall be in poly carbonate body (PC) / ABS, front
cover transparent Poly Carbonate/ABS, UV resistant, mechanical strength IK o9 (6J
impact) IP-55.
This equipment shall be installed in one of the line cubicle of all MV switchboard to
be supplied for the secondary substation.
In Praia City Network the earth fault indicator shall be installed also in all existing
Secondary substation where no rehabilitation is expected as indicated in the
following table
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3.4.4. MV/LV Power Distribution Transformer
One MV/LV indoor transformerfor each S/S, oil immersed type, hermetically sealed,
with the following characteristics in accordance to IEC 60076:
Rated power : 160 or 250 or 400 or 630 kVA
Rated voltage ratio : 20000/410V or
20000-15000/410 V
Rated frequency : 50Hz
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Method of cooling : ONAN
Impedance voltage at 75ºC and at main tap : 4%
Connection vector group : Dyn5
Tap range : +5%, -5%
Tap step : 2.5%
No. of tap positions : 5
Maximum short circuit level at HV terminals : 500MVA
Insulation level:
MV line terminal : LI 125 AC 50
LV line terminal : AC 3
Max accepted load losses at rated power : ***** W
Max accepted no load losses : *** W
Max accepted noise level (IEC 60551) : 58 dB
Painting : grey colour, RAL 7033
The transformers shall be provided with:
the convenient fittings and its own protective devices which trip the CB: at
least one thermometer with maximum indicator and an oil level indicator
plug-in bushings 200A-24kV on MV side
4 LV flag lugs
A switch for the MV voltage 15KV/20KV: controlled externally without
dismantling or removing anything.
A tap changer ± 2 x 2.5%. ; controlled externally without dismantling or
removing anything
3.4.5. Transformer feeders
The MV cable standardized to connect the RMU protection cubicle and the
Transformer plug in bushings shall be the ELECTRA standardized aluminium, XLPE
(IEC 60502-2), single core cable, 1x120 mm2 type.
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Pre-molded type connector with separable dead-break connector, 24 kV, 250A
according to IEEE 386-2001 shall be connectedto the transformers MV bushing,
The cables standardized to perform the connection between LV transformer bushings
and LV Distribution fuse board are single core, copper, non armoured, 0.6/1 kV, XV
95mm2cable, or single core aluminum, non armoured 0,6/1 kV, LXV 240 mm2 cable
in accordance to IEC 60502-2.
For 160 kVA transformers the connection shall be done through one cable per phase
and one cable for neutral.
For 250 kVA, 400 kVA and 630 kVA transformers the connection shall be done
through four cables per phase and two cables for the neutral according to the 1000 A
LV Fuse board to be supplied so that in case of future transformer upgrade it shall
not be necessary to replace the already existing cable connection.
The connectors to be used in both extremities of the cables must be crimpable, tined
copper, sized in accordance the characteristics of the LV bushings and of the LV
incoming load break switch terminals.
3.4.6. Low voltage distribution fuse board
According to the rate current there shall be two type of LV switchboard:
LV Switchboard 1000 A
LV Switchboard 250 A
3.4.6.1. LV switchboard 1000 A
The 1000 A LV distribution switchboard is designed for 250, 400 and 630 kVA
transformer stations. It shall be metal enclosed, self-ventilated, floor mountedfree-
standing typeor wall mounted, rated voltage 690 V ac, service voltage 230/400 V ac,
frequency 50 Hz, assembled on factory according to single line diagram represented
in drawing no.0.1.36.The electrical assembly includes:
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1 four-pole circuit breaker equipped with magnetic and thermal relays with a rated
current of 1000 A, being the thermal relay adjustable between 0,6 and 1 x In;
6 three-pole fuse(NHO1) for simultaneously opening, rated current 250 A,
equipped with 160 A fuse;
1 three-pole fuse(NHO1) for simultaneously opening, rated current 50 A, for
public lighting circuit;
1 bi-pole circuit breaker equipped with instantaneous differential relay, rated
current 25 A and 300 mA of sensibility;
One public lighting scheme including twelve single-pole 32A circuit breaker
supplied by one three-pole 50 A fuse breaker above defined, and controlled by
one three-pole 63 A contactor able to answer the following functions: Off-
Automatic-Manual;
The automatic control of the public lighting will be made of a photoelectric cell
and an hourly switch or an electric clock with 100 hours of running reserve and
two NO/NF contacts; The supply of each Distribution Fuse Board includes one
photo-electric cell to be installed outside the PT and the VV 2x1.5 mm2 cable to
connect it to the fuse board.
copper busbar 50 x 10 mm (phases) and 50 x 5 (neutral), rated current 1000 A,
rated short-time withstand current 30 kA, 1 sec;
the earthing connector necessary to connect the neutral coming from the
transformer and an earthing isolated cable of 50mm2, witch other end is
connected to neutral earthing electrode of the substation;
all the accessories for making proper connections of the equipment including the
metallic parties to earthing system and connectors where it can be possible to
earth the metallic shields of LV cables;
protection fuses for the measuring equipment;
the equipment for LV measuring, as described:
3 CTs 1000/5 A classe 1;
3 ampere meters 0-1000 A;
1 voltmeter 0-500 V, with a switch for 7 positions;
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1 Energy for the total active and reactive load (asymmetric load);
1 kWh meter for public lighting (asymmetric load):
The energy metering system in the transformer / LV switchboard feeder and the
metering system in the street lighting circuit shall be done, each one, by a ACE
SL7000 Meter Series - Smart energy meter from Actaris or equivalent. Both meter
shall be able to measure and display the following parameters:
active, reactive and apparent energy and power, three-phased on each phase,
import and export
three-phased power factor on each phase
instantaneous U on each phase
instantaneous I on each phase
phase switch UU, UI and cosφ
frequency
succession of phases
displays phase diagram P,Q
The meters information shall be readable online through a dedicated communications
port in order to allow user to monitor and control energy consumption, energy quality
and service quality. Local- and remote-reading ports and external telephone modem
have to be supplied from the meter.
The meters shall have the following electrical characteristics:
Rated voltage 3x57,7/100V up to 3x240/415V
auto ranging
Rated direct current In 5 A, Imax 120 A
Rated CTs connection current Ib 1A, Imax 10A
Network type 4 wire
Accuracy for direct connection Class1
Accuracy for transformer connected Class 0,2
Frequency 50 Hz
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Standards IEC 61036, IEC 60687
Communications IR-Port, 2RS485 DLM-Cosem,
Protocol
The following accessories shall be supplied:
Communications
External telephone modem
Cabling for external communications devices
IR-reading device for connection to PC
Configuration/Calibration
Customer software for consumption monitoring
Utility software for configuration
Utility software for calibration
Installation tools
Transformer ratio labels
Sealing kit
Documentation
Test certificate
User guide
Installation manual
3.4.6.2. LV Switchboard 250 A
This switchboard is designed to be installed in Pole mounted transformer station or
inside a masonry building of a transformer station, rated power 50 or 100 or 160 kVA.
Therefore the marshalling cabinet shall be outdoor type, with a degree of protection
IP-443, made of polyester in order to support the corrosion effects but also it must be
resistant to the UVR. It shall be rated voltage 690 V ac, service voltage 230/400 V ac,
frequency 50 Hz, assembled on factoryaccording to single line diagram represented
in drawing nº .0.1.35 .For Pole mounted installation, the marshalling cabinet shall be
equipped with all the accessories necessary to erect the cabinet on the pole.
The electrical assembly includes:
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1 four-pole circuit breaker equipped with magnetic and thermal relays with a
rated current of 250 A, being the thermal relay adjustable between 0,6 and 1 x
In;
4 four-pole circuit breaker equipped with magnetic and thermal relays with a
rated current of 125 A, being the thermal relay adjustable between 0,6 and 1 x
In;
1 bi-pole circuit breaker equipped with instantaneous differential relay, with a
rated current of 25 A and 300 mA of sensibility;
One public lighting scheme including eight single-pole 32A circuit breaker
supplied by one three-pole circuit breaker and controlled by one three-pole
contactor able to answer the following functions: Off-Automatic-Manual;
the automatic control of the public lighting will be made of an photoelectric cell
and an hourly switch or an electric clock with 100 hours of running reserve and
two NO/NF contacts;
copper busbar, rated current 250 A (2A/mm2) short-time withstand current 21
kA, 1 sec
the earthing connector necessary to connect the neutral coming from the
transformer and an earthing isolated cable of 50mm2, witch other end is
connected to neutral earthing electrode of the substation.
all the accessories for making proper connections of the equipment including
the metallic parties to earthing system and connectors where it can be
possible to earth the metallic shields of LV cables.
heating resistance with 60 W protected against accidental contacts. The
marshalling cabinet shall be prepared in its lower side to accept the
connection of the mentioned incoming cable from the transformer, the four
outgoing aerial bundled cables 4 x70 + 2x16 mm2 and the earthing wires.
The equipment for LV measuring, as described :
3 CTs 250/5 A classe 1;
3 ampere meters 0-250 A;
1 voltmeter 0-500 V, with a switch for 7 positions;
1 Energy for the total active and reactive load (asymmetric load);
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1 kWh meter for public lighting (asymmetric load):
The energy metering system in the transformer / LV switchboard feeder and the
metering system in the street lighting circuit shall be done, each one, by a ACE
SL7000 Meter Series - Smart energy meter from Actaris or equivalent. Both meter
shall be able to measure and display the following parameters:
active, reactive and apparent energy and power, three-phased on each phase,
import and export
three-phased power factor on each phase
instantaneous U on each phase
instantaneous I on each phase
phase switch UU, UI and cosφ
frequency
succession of phases
displays phase diagram P,Q
The meters information shall be readable online through a dedicated communications
port in order to allow user to monitor and control energy consumption, energy quality
and service quality. Local- and remote-reading ports and external telephone modem
have to be supplied from the meter.
The meters shall have the following electrical characteristics:
Rated voltage 3x57,7/100V up to 3x240/415V
auto ranging
Rated direct current In 5 A, Imax 120 A
Rated CTs connection current Ib 1A, Imax 10A
Network type 4 wire
Accuracy for direct connection Class1
Accuracy for transformer connected Class 0,2
Frequency 50 Hz
Standards IEC 61036, IEC 60687
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Communications IR-Port, 2RS485 DLM-Cosem,
Protocol
The following accessories shall be supplied:
Communications
External telephone modem
Cabling for external communications devices
IR-reading device for connection to PC
Configuration/Calibration
Customer software for consumption monitoring
Utility software for configuration
Utility software for calibration
Installation tools
Transformer ratio labels
Sealing kit
Documentation
Test certificate
User guide
Installation manual
3.4.7. Civil Works
3.4.7.1. PUC – (Poste UrbanoCompacto) or Stainless Steel Compact
substation
This substation shall be totally manufactured in stainless steel, protected against
corrosion and resistant to the most aggressive environments, it shall have a special
ventilation system preventing condensation and highly flexible internal space
distribution (Capacity for one transformer from 250kVA up to 630 kVA, one RMU and
one LV Switchboard, it shall be easy to transport and to assemble, reduced
installation area (1500x3200mm), reduced maintenance and anti-vandalism
protected.
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All the equipment shall have the same specification above described. The
transformer / LV switchboard feeder shall be for 1000 A.
The stainless housing shall be installed on a concrete base exceeding the limits of
the metallic housing at 15 cm. The detailed design of the concrete base shall be
provided by thecontractor.
3.4.7.2. Masonry building
The buildings shall be a standard type represented in the respective drawing.
The metallic ventilation louvers, the door and the trench covers details are
represented in the drawing no. 0.0.18.
The structure of the buildingfoundations, pillars, beams and a roof shall be made in
vibrated reinforced concrete. All the reinforcement bars of these elements must be
firmly tied at their junctions. Reinforcementsteel bars shall be firmly electrically
interconnected and shall be earthed at two opposite points.
The steel reinforcement of the roof slab shall be at 1.5 cm from the bottom and those
of the beams and pillars at 2 cm from the surface.
Load on the roof slab is 2,0kN/m2 for calculation.
The formworks shall be strong enough for the vibration without loss of concrete and
shall be removed only after 14 days from the concrete pouring.
The walls shall be based on the foundation of basaltic rock with mortar of
cement/sand T1:5. Theyshall be at least 0,6m X 0,6 m, in an opened trench.
The foundations of pillars in reinforced concrete shall be calculated for permissible
tensions of the soil, equal or superior to 1MPa.
The indoor trenches for cables shall be built simultaneously with the foundations in
masonry of E20 concrete blocks, and mortar cement/sand in a proportion of 1:4
The walls shall be built with concrete blocks thickness of 20 cmand mortar
cement/sand in a proportion of 1:4.
PVC pipes with a diameter of 160 mm, both for cables entrance shall be properly
located and tied before being embedded in the concrete.
The steel shall be A400 and the concrete B20 type.
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The concrete mixing water must be controlled in proportional doses in relation to
cement 0,6 - 0,8.
The proportion cement/sand/gravel of the concrete one is of 1:2: 4, with an average
of 300 kg of cement per cubic meter.The gravel must be dia20-30 mmexempt of dust.
Sand and aggregate from the seashore and salted water are forbidden.
Finishing
The substation roof shall be waterproof to prevent water leakage into the substation.
Walls and roof shall be surfacing with a mortar of cement/ sand and painted with one
coat of liquid prepolymer sealing and three finishing coats of white color acrylic resin
(gloss finish).
Floor shall be painted with one coat of polyurethane sealer and two coats of gray
color epoxy dust proof coating.
A screed concrete made with cement/sand 1:3 shall be poured on the floor slab and
the screed shall be surfaced for asmooth finishing.A steel welded mesh,
100x300mm; made of Ø3.8 mm steel rods shall inserted 2 cm deep in the
screed.Before the pouring, the wire mesh shall be welded to non insulated 35mm2
copper conductors in five different rods at least. These cablesshall be connected to
the earthing protection system of the MV RMU and of the LV Fuse Distribution board
respectively.
The doors and louvers must be hot deep galvanized and the lock of the door shall be
the standard ELECTRA type.
In the right side of the door, a standard label with the symbol of ELECTRA the
indication of “High Voltage/Danger” written in Portuguese language “Alta Tensão/
Perigo de Morte” and the number of the secondary substation shall be installed.
Before the cables installation, pipe entrance shall be close by a wood board. Afterthe
cables are laid and connected, pipes shall be sealed with mastic or paper/cement in
order to inhibit entrance of any animal.
3.4.8. Earthing Systems
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The protection earthing system is separated from the neutral earthing circuit. The
earthing resistance shall be lower than 10 Ohms for each one.
The distance between any buried parts of the two systems cannot be less than 20
meters.
The standard earthing electrodes are electrolytic copper plates (1000x500x2.5mm)
installed vertically, being the larger side horizontally placed at a deep from surface of
1 meter. However earthing rods installed vertically, with the head at 1m deep, and
paralleled with main electrode, can also be used in order to reduce earthing
resistance.
The details design of the earthing systems for different models of secondary
substations and switching stations are indicated in the common civil
0.0.02/04/06/08/10/12/14/16.
3.4.8.1. Protection Earthing System
A ring of non insulated 50 mm2 copper conductor shall be buried at 1m deep all
around the building and at 80 cm from the foundation. All the protective earthing
rods shall be connected to this buried ring being by a 50 mm2 conductor. The
metallic structure of the building shall be also connected to the buried ring at least in
two points. The connections shall be made by welding process or by effective
crimping process using cooper C connectors and adequate tools.
A loop of the buried circuit is connected to a disconnectable connector (for earthing
metering purposes) located on the wall inside the building near the door.
From this connector, a ring of a copper conductor 50mm2 shall be installed on the
wall inside the building. A 35mm2 copper conductor shall earth all the main
equipment and metallic parts of the building. Transformer tank, cover and cable box,
LV Distribution fuse board, MV RMU shall be connected at least at two opposite
points.
Flexible copper conductors 16 mm2 shall interconnect the door frame and the door
with a loop large enough to avoid breakage.
Reinforcement steel embedded in the floor must be also earthed by a 35 mm2
copper conductor.
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3.4.8.2. Transformer Neutral Earthing System
One or more earthing electrodes must be connected directly to one disconnectable
connector (for metering purposes) by copper cable 1x50mm2, 0.6/1kV, VV (Double
insulating core), which external sheath shall be black colour and the internal sheath
shall be blue colour.
The connecting cable must be buried 1 m deep and be mechanically protected by
auPVC pipe of small diameter and strong wall.
Transformer Neutral shall be connected to the disconnectable device on the wall
inside the building by an insulatedcopper cable of 50mm2, 0.6/1kV, VV.
3.4.9. Accessories
In the secondary substation it shall be installed:
One wall board protected, with instructions for first help, written in Portuguese
language, to be observed in case of electrocuted people.
One set of rubber gloves duly insulated for 24 kV;
One slightly raised platform insulated for 24 kV;
Onefireextinguisher extintor de incendios de CO2 de 5 kg
Placa indicativa de perigo de morte
Quadro de medição de resistência de terra
The civil works rehabilitation to be doneareas follows:
After execution of the preparatory works it will be necessary:
Remove of the existing masonry cells and repair walls internally and
externally.
Substitute the existing door and ventilation louvers, adopting the present
standard equipment for PTs when possible;
4. MV OVERHEAD NETWORK
4.1. GENERAL
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For rural electrification in all Santiago, Fogo and Maio Islandsthe existing MV
Overhead network shall be extended, rehabilitated and /or upgraded.
The designs are completely performed and they shall be described in the text,
drawings and pole maps.
The new overhead MV lines will be three phase type, as the existing ones, and shall
be implemented using 54,6mm2 Aster cable for pine type insulator or 148 mm2 aster
cable for suspension type insulator in 10 or 12 meters wooden polesin case of
straight line poles and 12 meters metallic towers in case of angle or end of line.
Silicone line poste stand-off insulator and silicone long-rod Insulators shall be used in
all new overhead lines.
The cross arms shall be Sheet-arch type for pin type or for suspension type following
the French standard (NappeVoute).
The secondary substation in all rural electrification shall be mainly pole mounted
type.
The topographic profile and plan view of all MV line route and mechanical data
calculations made by Electra Staff are given in the respective drawings. The
contractor is requested to verify and confirm all the calculation. The geographical
co-ordinates of each pole of the lines shall be provided to the contractor by the
employer.
In what concerns the identification of the 20 kV line, each supporting structure shall
be identified by one anodized aluminium label, with a convenient size to be read from
soil and with the following text written in Portuguese language: ELECTRA / Linha 20
kV no. .. / Apoio no. i. (the line numbers will be indicated later on).
The contractor has to supply and install all the equipments.
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4.2. SCOPE OF WORK
The total linear length of the Aster 54,6 mm2 overhead network for rehabilitation and
rural electrification in the three island shall be 88,4 km and the total linear length of
the aster 148 mm2 overhead network shall be 7,5 km.
The OH network in each island shall be installed as indicated in the following tables:
Santiago Island
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Fogo Island
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Maio Island
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4.3. EQUIPMENT SPECIFICATION
4.3.1. Supporting structures - Poles
4.3.1.1. Wood poles
The wood poles shall follow the French Standard NF C67-100 or at least equivalent
one.
The poles shall have a circular cross-section and a conic profile with 12 mof total
length.
The trees used may have characteristics of adult wood.The poles shall be treated
with efficient product according to the characteristics of the original trees in order to
preserve its longevity, but the preservative shall not reduce significantly the dielectric
strength of the wood.
The poles shall have a right axis.It is not acceptable that the line between the centres
of the cross sections limiting its useful length can come outside the pole anywhere
along its total length.
The pole portion to be under grounded must be prepared to offer resistance to rain
water penetration, with recourse to reinforced treatment, namely to be painted on its
underground portion and until 20 cm out of soil with an adequate thickness of
bituminous.
According to the mechanical strength, two types of poles can be used:
1. Wood pole12 meters (type S325 or similar)
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maximum horizontal force at 0.25m from top: 3.25 kN
minimal diameter on top (d) - 19 cm
minimal diameter 1 m far from the bottom (D) - 26/28 cm
2. Wood pole 12 meters ( type S 550 or similar)
maximum horizontal force at 0.25m from top: 5.5kN
minimal diameter on top (d) - 23 cm
minimal diameter 1 m far from the bottom (D) – 30.5/33cm
The measurement of the two diameters(d et D) shall be done after final surface
planning.
In some cases it is adopted the solution of double poles and in other cases are
foreseen H wooden structures (porticos) witch legs can be made of single poles or
double poles and using X steel braces to connect both legs.
When double poles (geminated) are used, the union of both poles shall be done
using hot deep galvanized bolts, according to the French Standards each 2,5metrs
as indicated in the drawing nº 0.0.24.
It is requested in each pole the permanent inscription of
supplier’s name;
impregnation treatment used
year of fabrication;
total height (m);
maximum horizontal force;
These inscriptions shall be made on a support resistant to the impregnation material.
4.3.1.2. Metallic towers
For the strong angles and end of lines the metallic structures to support the line will
be steel, hot deep galvanized, lattice type or polygonal towers, sized as mentioned
on the Poles Map, which design and mechanical calculation is responsibility of the
contractor. Galvanizing shall be made by immersion in a zinc tank, where Zn purity
shall be not less than 98.5%, and which temperature shall be between 450 and 460
ºC. The towers shall be painted on its underground portion and until 20 cm out of soil
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with an adequate thickness of bituminous painting, adherent to galvanized structure,
to give the tower a better corrosion protection.
As indicated in the different pole mapsthe following metallic towers will be used:
Metallic simple tower 12m / 16 kN
Metallic simple tower 12m / 20 kN
Metallic simple tower 12m / 25 kN
Metallic simple tower 12m / 32 kN
Metallic simple tower 12m / 40 kN
4.3.2. Cross arms
The cross arms must be metallic hot deep galvanized by immersion in a zinc tank,
where Zn purity shall be not less than 98.5%, and which temperature shall be
between 450 and 460 ºC.
According to the EDF Software Camelia, used for the mechanical calculations of the
lines the cross arms shall be the following type or equivalent:
For pine type insulator, 54,6 mm2Aster cable line on the straight line poles:
Sheet-arch type cross arms
NVR 1
NVR 2
For suspension line, 148 mm2 Aster cable on the straight line poles:
Sheet-arch type cross arms for area with strong wind
NW2 70x70
NW2 90x90
For angle poles and end line poles in both 54,6 and 148 mm2 Aster cable it shall be
used the following cross arms:
Single tube cross arm "X" type beams: NA2X 2500 D or equivalent
Single tube cross arm "X" type beams: NA3X 4000 D or equivalent
Single tube cross arm "X" type beams: NA3X 6300 D or equivalent
Single tube cross arm "Y" type beams: NA3Y12.500 S or equivalent
Single tube cross arm "Z" type beams: NA3Z20.000 D or equivalent
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Single tube cross arm "X" type beams: NA4X 6300 D or equivalent
Single tube cross arm "X" type beams: NA4X 16000 D or equivalent
Single tube cross arm "X" type beams: NA5X 16000 D or equivalent
Single tube cross arm "X" type beams: NA6X 20000 D or equivalent
4.3.3. Insulators
All the insulator shall be silicone type in order to resist the very pollutant environment
in all Cap Verde island:
The insulator has to be manufactured withelectrical grade corrosion resistant epoxy
rod. Thematerials used has to be the highest quality and routinely tested to ensure
the maximumperformance characteristics.The fittings has to be machined from EN8
or cast frommalleable cast iron and hot dip galvanized inaccordance with ISO1461.
The sheds has to be manufactured using high-pressureinjection molding techniques
to create a smoothsurface reducing the amount of pollution trap.
Standards
The post stand-off insulator shall be manufactured in accordance to IEC 61952 and
the long-rod Insulators shall be manufactured in accordance toIEC 61109 & IEC
62217. A quality processes shall be implemented as per ISO 9001:2000.
Post stand-off insulator characteristic
Lightning Impulse
Withstand Voltage (kV)
1 min Power frequency withstand (wet) (kV)
Minimum Arcing
Distance(mm)
Minimum Creepage Distance
(mm)
Specified cantilever
load (kN)
Maximum Design
Cantilever load (kN)
250 112 350 1118 12,5 5
The pin insulators shall be equipped with adequate bolts for mounting on the cross
arms.
Long rod insulator characteristic
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1 min Power frequency withstand (wet) (kV)
Arcing Distance
(mm)
Minimum Creepage Distance
(mm)
Specified Mechanical
load (kN)
121 380 1200 70
The string accessories shall be able to support fault currents of 1 kA - 1 second and an
ultimate strength of 70 kN.The current density on accessories can never be higher
than 70 A/mm2.
4.3.4. Aerial Conductor Cables
The conductor cables shall be ASTER 54.6 mm2 and ASTER 148 mm2 with the main
characteristics as follow:
Characteristics ASTER CABELE 54,6 ASTER CABELE 148
Commercial Designation Aster 54.6mm2 Aster 148 mm2
Conductor material Aluminum Alloy Wires Aluminum Alloy Wires
Nominal Section (mm2) 54.6 148 mm2
Overall Diameter (mm) 9,45 15,75
Numberofaluminiumwires 7 19
Wire diameter (mm) 3.15 3,15
Ultimate strength (KN) 17,73 48,12
Linear Weight (kg/Km) 149 406,5
Elasticicity modulus (N/mm2) 62000 60000
Linear temperature expansion coefficient (/ºC) 23,0E-06 23,0E-06
DC electrical resistance at 20 ºC (ohm/Km) 0.603 0,2239
4.3.5. Pole mounted secondary substation
For the electrification of rural villages, the bidders are requested to offer the price for
the completely supply and installation of pole mounted secondary substation for 50 or
100 kVA. Each secondary MV/LV substation is composed by:
One metallic tower
One outdoor air breaking switch
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One MV/LV transformer
One LV switchboard
three lightening arresters
Earthing System
One set of Line / Transformer connections
One set of Transformer / LV switchboard connections
4.3.5.1. Scope of work
The pole mounted secondary substation shall be installed in the three island as
indicated in the following tables:
Santiago Island
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Fogo Island
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4.3.5.2. Pole
The pole must be steel made, lattice type,hot deep galvanized, with 12 meters of total
length,being the maximum horizontal strength force at 0,25 m from the top 16kN.
With the pole shall be supplied all the accessories necessaries to support the
transformer. The metallic tower for pole mounted transformer will follow the same
specification as the line metallic tower, in chapter 23.3.1.2.
4.3.5.3. MV/LV transformer
One three phase transformer, outdoor, pole mounted type, with the vector group
Dyn5, oil insulated and with it shall be supplied the accessories for connection of the
HV (bimetallic) and LV cables.The accessories for the erection of the transformer on
the pole as well as those for support the lightening arresters must also be included in
the supply.
Electrical characteristics:
-rated power: : 100 kVA or 50 kVA
- primary voltage : 20 ± 2x2,5 % kV
- secondary voltage : 410/236 V
- short circuit voltage at75°C : 4 %
- no load losses : 380 W>/ >200 W
- load losses :1800W > / >1200 W
All the external transformer coverage shall be made of special hot deep galvanized
steel plate with a special marine protective paint in order to ensure the anticorrosion
protection in an extremely aggressive environment.
4.3.5.4. LV switchboard
The LV switchboard shall be 250 A types, according to the specifications above
described on chapter 22.4.6.2.
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4.3.5.5. Electric connection between transformer and MV line
The MV OH lines will be made of ASTER 54,6 mm2 conductors, or ASTER 148
mm2. The connection between the line and the transformer HV bushing insulators
and with the lightening arresters shall use the same 54,6 Aster conductor type.
4.3.5.6. Electric connection between transformer and LV Switchboard
This connection will be made of a XLPE copper cable 3x95+50 mm2 type, for
protected inside a light grey PVC pipe with 75 mm of diameter, which top shall be
equipped with a curvature inhibiting rain water penetration.
The supply shall include 14 m of cable and 10 m of PVC pipe for each distribution
substation.
4.3.5.7. Earthing System
The protection earthing system is separated from the neutral earthing circuit. The
earthing resistance shall be lower than 10 Ohms for each one.The distance between
any buried parts of the two systems cannot be less than 20 meters
The standard earthing electrodes are electrolytic copper plates (1000x500x2.5mm)
installed vertically, being the larger side horizontally placed at a deep from surface of
1 meter. However earthing rods installed vertically, with the head at 1m deep, and
paralleled with main electrode, can also be used in order to reduce earthing
resistance.
The supply shall be according to chapter 22.3.6.3
4.3.6. Earthings
4.3.6.1. Earthing of Cross Arms
The cross arms as well as other metallic structures, like X brace structures, shall be
earthed through an insulated 0.6/1 kv copper cable with a cross section of 35
mm2,protected 0.20 m under soil surface and 2.50 m above soil surface by an
adequateextruded uPVC cable protection fixed to the pole by stainless steel bands.
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4.3.6.2. Earthing of Metallic Towers
The contractor will supply and install all rods, counterpoises, cables, connectors and
accessories that may be necessary for grounding the structures.
Grounding rods should be solid high conductivity copper complying with ANSI UL 467
norm, or equivalent. Rods should have a circular section and a minimum diameter of
1.59cm, a minimum length of 1.8m and should have pointed ends. Rods will be
supplied with their respective connectors and shall be 1 for each metallic simple
tower, and one for each leg of the metallic portico towers, placed on one external
corner of the excavation pits.
Grounding conductor shall be high hardness copper 35 mm2, insulated 06/1kV
Where metallic towers foundations are built in frequented public spaces, one ring of
non insulated 35 mm2 cooper cable shall be performed at rod head level
interconnecting the rod or rods in de case of metallic portico towers, running 1 m
distant from the structure(s).
At points where electrical resistance is higher than 20 ohms, the Contractor, in
coordination with the Project Manager will determine the type of counterpoise to be
installed. The Contractor will make available an extension of at least 2m of 35 mm2
copper conductor to connect counterpoises outside the foundation. Counterpoises
will be installed within ditches at least 80cm deep, and covered with earth.
4.3.6.3. Earthing of Pole Mounted Secondary Substations
The earthing electrodes will be made of a copper plates with 1000x500x2 mm,
connected each one to an isolated earthing copper conductor with 20m and a device
to give the possibility to proceed on earth measurements.
The supply shall include, for each substation:
two copper plates 1000 x 500 x 2 mm
2 x 20 m of LV insulated copper conductor with 50 mm2
earth measuring devices
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6 copper compression connectors for the 50 mm2 copper cable with a bolt
hole of 1/2”
hard brass bolts Ø1/2” with two 30x30x2 mm square copper washers, one
nut and one back nut (to bolting the copper connectors on the copper
plates)
4 hard brass bolts with two round brass washers, one nut and one back nut
t fix the cooper cable on the earthing measuring device.
2 x 5 m of non insulated 50 mm2 cooper cable.
4.3.7. Lightening arresters
Every pole mounted transformer shall be protected against atmospheric surge by one
lightning arrester, 24 kV - 5 kA per phase and all the transition from overhead line to
underground cable shall be protected by one lightning arrester, 24 kV - 10 kA per
phase.
Lightening arresters earthing shall be done through dedicated 35 mm2, earthing
isolated 0.6/1 kV cable connected to a dedicated earthing rod. Earthing cable shall
be protected 0.20 m under soil surface and 2.50 m above soil surface by an
adequate stainless steel pipe fixed to tower by stainless steel U bolts.
4.3.8. Outdoor air breaking switch
Electrical specification:
Rated voltage: 36 kV
Rated current: 100 A
Breaking capacity: 50 A
Closing capacity: 6.3 kArms
The air breaking switches must be supplied with all the accessories necessaries to its
proper erection on the metallic poles, as well as their mechanical manual control.
4.3.9. Outdoor Load Break SwitchDisconnector with Remote Control Unit
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In order to guarantee the quality of electrical service, by reducing the power outages,
the duration of outages bidders are requested to specify and quote the supply and
installation of load break switch-disconnectortype PM6 from Schneider or equivalent
to be mounted on metallic or wood poles as indicated in poles map and tables
hereafter.
The load break switch-disconnectorshall be manufactured in accordance to IEC
60265-1, IEC 62271-102, IEC60694, IEC 60529, IEC 62271-200 IEC 60815. A
quality production processes has to be implemented as per ISO 9001:2000.
The disconnector switch breaking chamber and the SF6 gas shall be inside a
compact external enclosure. The risk of any gas leakage has to be reduced. The
enclosure has to be sealed and meets “pressurized sealed system”.
The external enclosure shall be made of a stainless steel, without any additional
protective coating, to give a smooth, clean, self-cleaning and aerated surface that
should be highly resistant to corrosion.
The casing has to be connected to earth in order to avoid the possibility of dangerous
leakage current to pass between the terminal on one side and the terminal on the
other side when the device is on the open position. No additional disconnector shall
be necessary to guarantee the insulation distance.
The disconector switch shall be equipped with 6 silicone connectors enabling
connection of the MV line using a non insulated cable.
The general electrical characteristics shall be the following:
Rated voltage: 24 kV
Rated current: 400 A
Breaking capacity: 400 A
Closing capacity: 31,5 kA rms
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The load switch breaker shall be equipped with a manual-electrical control unit. The
manual equipment control and operation shall be made using a rod system with
mechanical locking to block the OPEN-CLOSED positions. In order to avoid the
possibility of being operated by someone from outside of the company.
The electrical switching and control mechanism shall be located inside an
independent enclosure combined with the disconector switch breaking device.
The basic mechanism involves an opening-closing system activated by a spring for
switching operations to take place independently of the operator switching speed.
The control unit shall be EASERGY TYPE T200P from Schneider or equivalent to be
pole-mounted outdoors, in a stainless steel casing. The unit shall comprise the
following components:
A cradle for all electronic modules
Switch connection module
CPU and the local control indication module
RTU communication module
Battery power supply charger module
A battery
A supply transformer with its protection device
Free space to install a radio or a modem
A outdoor voltage transformer shall be necessary in order to provide the auxiliary
power supply to power the control unit charging device, including the radio and its
electronic circuit boards needed for independent operation of all equipment. The
voltage transformer shall give the necessary voltage presence and absence signals
in order to carry out on the disconnector function and setting by remote control.
A three single phase lightning arrester of Zinc Oxid Type 24 kV, 5 kA, on each
side of the disconnector shall be installed on an appropriated support frame to
protect the equipment from overvoltage resulting from atmospheric condition.
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The load break switch disconnectors shall be installed as indicated in the following
tables:
Santiago Island
Fogo Island
Maio Island
4.3.10. Directional Fault Current Indicator for Overhead 20 kV Network
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In some specific points of the MV 20 kV three phase overhead networks it shall be
installed a intelligent directional fault-current indicator.
The line fault indicator shall be able to locate short-circuit /Phase To Phase (PTP)-
and earth faults/PhaseTo Earth (PTG) in overhead line distribution networks with
isolated or impedance earthed neutral.
Upon detecting a fault on the line, the indicator gives off an intermittent red or green
light-flash(LED). One LED flashing indicating an earth-fault and both LED flashing
indicating an short-circuitfault. Xenon flash shall be supplied. The colours of the LED
will also indicate direction to the fault location for earth-faults.
The line fault indicator shall be equipped with an internal relay-card, giving the
possibility for connection to the communication devices of the following four different
relay-output’s to an RTU:
Transient Fault in red direction
Transient Fault in green direction
Permanent Fault in red direction
Permanent Fault in green direction
The housing and bracket material of the fault indicator shall be:
Body&Brakett: Poly Carbonate (PC) with glass reinforcement
Topcap&Display unit: Transparent Poly Carbonate, UV resistant Mechanical
strength IK o9 (6J impact)
Flame retardant grades: (V-0 UL ) 750 oC
The fault indicator shall be powered by lithium battery giving some 7-10 years battery
lifetime in normal service equivalent to more than 500 hours of flashing capacity
When the unit is activated The battery have to be fitted with a connector for simple
replacement.
The indicators shall be placed at strategic locations along the line such as after
branching points and sectionalisers as indicated in the tables hereafter. They shall
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be mounted on the pole, 4-5 meters below the conductors, by means of screws or
wrapping-bands. Live line mounting have to be done safely, easily and rapidly.
The current fault indicators shall be installed as indicated in the following tables
In Santiago Island
In Fogo Island
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In Maio Island
4.4. OVERHEAD NETWORK CONSTRUCTIONS PROCEDURES
4.4.1. Anchoring and erection of metallic structure
a) Assembly and erection of structures will take place only after inspecting and
selecting all elements at the site, and verifying that they comply with plans and
drawings in order to detect any missing element. Erection of structures may only
take place after two weeks after pouring concrete for the foundations.
b) In no circumstances shall defective or bent pieces be mounted; if the Contractor
discovers any such defects, immediate notice should be given to the Project
Manager, without whose approval no corrections or modifications are to take
place.
c) Step bolts will be provided to inspect the structure. Anti-escalation devices will
be installed on the structure, immediately below the first step bolt.
d) Signaling. All structures will be clearly identified through two numeration signals
and two danger signals. Structures at the departure from or arrival to the
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substations will have signals indicating the relative location of phases on the
structure.
4.4.2. Foundations
The Poles Map indicates the minimum required foundation size for each pole
according to Camelia software, used for the mechanical calculation.
In the case of metallic structures the contractor has also to present and to follow the
manufactor’s foundation datas.
The foundations for line metallic towers or pole mounted secondary substation
metallic towers and for strong angles wood poles are to be concrete filled.
In the case of wood poles, when in alignment, it is foreseen the use of rock and
compacted earth layers as mentioned in the Common drawing 0.0.22 e 0.0.23.
However, the contractor shall perform an investigation of soil mechanics in order to
adopt the better solution according to the requirements, and to determine its quality
relative to expected stresses, and to assess the amount of material to be removed
and the consequent expected volumes of concrete and rock.
4.4.2.1. Concrete foundation works
The foundation massifs will be constructed in simple or reinforced concrete according
to the soil characteristics and the contract includes the supply of materials and
equipment, and the pouring, finishing and curing of concrete in accordance with
approved plans and specifications.
Indicative specifications for materials used in foundations works
a) Cement: concrete shall be produced with Portland cement following ASTM
norm C-150, or equivalent. Cement used in the works will be adequately
packed and stored to protect it from humidity. Cement stored for over two
months, or which may have partially set, may not be used for the works.
b) Aggregates used for concrete should comply with ASTM norm C-33, or
equivalent, for concrete aggregates. Other aggregates that do not comply with
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this may be used, but prior consent from the Employer must be requested, and
assurance should be provided that they comply with the required resistance
and durability. Particular aggregate conditions include the following:
b1) Sand, which should consist of hard, dense, durable clay-free and dirt-free
grain; a maximum 5% should pass through US Standard No. 200, or
equivalent, sift; inadequate substances should not exceed 7%; sand should be
graded and when sift tested it must exhibit an ASTM C-33, or equivalent,
degree of fineness;
b2) Thick aggregate; gravel or equivalent (crushed rock) should have a
maximum size of two cm. Aggregate should be roughly round or cubed and
must be free of particles. It must be strong, hard and free of dust, clay,
organic material or other materials.
b3) Additives to improve mixture specifications may be used, but must be
approved by the Employer; in reinforced concrete applications, the use of
calcium chloride or other corrosive substances will not be allowed.
b4) Water used for concrete or mortar as well as water used during the curing
period must be clean and free of impurities such as oils, salts, alkaline
substances, or organic material.
c) Concrete mixture will consist of Portland cement, water, and rocky aggregates,
both fine and coarse. The contractor will provide samples of the mixtures to
be used in the works, including sets of concrete cylinders to be tested 7, 14
and 28 days after mixing according to ASTM, or equivalent, procedures.
Approval of test material does not imply the acceptance of concrete works, nor
does it exempt the contractor from complying with specifications and plans.
d) Concrete will be classified according to its resistance to compression 28 days
after mixing, as follows:
• Reinforced concrete: minimum resistance of 210kg/cm2
• Simple concrete: 140kg/cm2
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• Cyclopean concrete: 100kg/cm2 with aggregates of up to 20cm
diameter
e) Steel: reinforcing steel will consist of steel rods complying with ASTM norm A-
615, or equivalent.
4.4.2.2. Construction procedures: Concrete Specifications
a) Excavation of foundations: before pouring concrete, excavations must be
finished; any damage after acceptance must be repaired by the Contractor
using acceptable procedures.
b) Mixtures: proportions must be those previously approved in the design plans.
Changes in cement, aggregates, or proportions thereof require the Employer’s
authorization. Mixture time, after components are put into the mixer, shall not
be less than 1.5 minutes. Concrete should be mixed in quantities that allow
for its immediate pouring.
c) Concrete pouring should not produce segregation of materials or displacement
of reinforcing steel. The mixture should not be poured from heights above
1.5m.
d) Vibration. All concrete should be compacted using mechanical vibrators, with
the exception of small structures subject to minor loads. Vibration should be
uniformly applied to the mixture, and should be stopped before it causes
segregation or mortars. Vibrators shall not be in contact with reinforcing steel.
e) Curing. Concrete surfaces should be cured with water or with an approved
waterproofing agent. Water curing should extend to seven days, during which
time all surfaces must be kept damp. Waterproofing should be applied as
soon as setting water has evaporated.
f) Finishing. Top concrete surfaces should end in a diamond point shape to
allow drainage.
g) Trials during construction. Consistency of concrete mixture supplied should
be controlled using a slump test for each batch. During each pouring, the
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Contractor will provide three sample cylinders taken from different batches.
The Contractor will test the sample after 28 days in accordance with norms
mentioned previously.
h) Tolerances. Admissible tolerances for the acceptance of concrete works on
site are:
Thickness: -1 to +2cm
Upper limits: +1cm
Covering thickness: +/- 10% of that indicated on the drawings
Spacing of rods: +/- 2cm
For pre-fabricated elements, tolerances are 1/5 of those for on-site concrete.
i) Repairs. Concrete repairs must be performed by expert personnel. The
Contractor will correct imperfections within 24 hours of having dismantled the
frames, where fractures, holes or other defects are apparent.
4.4.2.3. Construction procedures for foundations
a) Foundations shall in principle be concrete and comprise the following types:
concrete footing with anchor bolts, concrete foundation with embedded
structure, or rock anchors if conditions allow them.
b) Excavation. This task comprises all excavations contemplated in the
drawings, as well as all additional works necessary to guarantee the stability of
slopes, the preparation of surfaces and all controls necessary to put the
foundations in place. It will be the Contractor’s responsibility to excavate
according to drawings; excess excavation should be filled up with approved
material. Inadequate material at the foundation level shall be excavated and
replaced by selected material or simple concrete. The Contractor shall not
finish the excavation to the foundation level until ready to pour the concrete.
Waste material shall be disposed of according to procedures defined by the
Project Manager. This also applies to the use and handling of explosives.
c) Compacted fillings. This task involves filling and compacting for the
foundations, leveling them with materials from the excavation or from other
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sources and following drawing dimensions. Material used should be free of
roots, construction waste or other organic material.
4.4.3. Conductor stringing and sagging
a) The Contractor is responsible for supplying, classifying, storing, controlling,
transporting to site and correctly installing line conductors, clamps, trusses,
vibration dampers, insulators, and all other accessories required for putting the
new lines in service, and its satisfactory operation according to approved
designs and drawings.
b) The Contractor shall provide a suitable means of communication, such as an
adequate telephone system or radio transmitter and receivers for use by crews
during stringing and sagging operations. The communication system used
shall be subject to the Project Manager approval.
c) The Contractor may not pursue stringing operations in bad weather conditions,
i.e. under rain or during electrical storms. If bad weather develops during
stringing operations, work should be immediately suspended and restarted as
soon as atmospheric conditions are back to normal.
d) The Contractor will propose the method and equipment to be used for
stringing conductor wires. Before initiating the stringing, the Contractor will
allow the Project Manager to examine the equipment, showing calibration
certificates for all equipment requiring prior calibration.
e) Prior to initiating the stringing, all protective equipment and temporary
structures should be in place. The Contractor is responsible for all measures
required to protect the conductor during stringing.
f) Stringing will be executed using best practices. Conductors must be handled
with care. Conductors shall neitherbe trampled on nor run over by vehicles.
Each reel shall beexamined and the wire inspected for cuts, kinks, or other
injuries. Injured portions shall be cut out and the conductor spliced. The
conductors shall be kept clean and shall not be allowed to contact the ground,
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guard structures or any object which in the opinion of the Project Manager
may cause abrasion or damage to the conductors. The Contractor shall
continuously inspect the conductor as it leaves the reel. If nicks or scratches
are detected, the stringing operation shall be stopped until the blemish is
smoothed with fine sandpaper or emery paper. If any broken aluminum
strands are found, splice rods shall be installed in accordance with the
manufacturer’s recommendation. If more than three broken aluminum strands
are found within any 300m section of cable, the cable section containing the
broken strands will be cut out and a full tension splice installed. Any damaged
wire, resulting from the Contractor’s negligence, shall be repaired or replaced
at his expense. The conductors shall be pulled over suitable rollers or
stringing blocks properly mounted on the pole or crossarm if necessary to
prevent binding while stringing.
g) Conductors shall be sagged in accordance with the conductor manufacturer's
recommendations. All conductors shall be sagged evenly. The air temperature
at the time and place of sagging shall be determined by a certified
thermometer. The sag of all conductors after stringing shall be in accordance
with the employer’s representative instructions. During stringing, conductor
sag should be at least 20% above the values indicated in the sagging charts.
Conductors shall hang in the Stringing blocks not less than two (2) hours nor
more than 48 hours before it is brought up to final sag.
h) The shield wire shall be sagged in accordance with the stringing data for each
shield wire. Stringing sag and tension data for expected conditions will be
approved by the Project Manager. No minus tolerances from the sag data will
be allowed and the plus tolerance shall be two percent of the stringing sag, but
not to exceed 10cm. Tension tolerances shall be within those values for
tension calculated and shown on the data sheets supplied that correspond to
the respective sag tolerances for the condition of concern.
i) The Contractor shall submit to the Project Manager for review, prior to the
starting of his stringing operations, the procedure to be followed in stringing,
sagging, and clipping-in of the shield wires. This procedure will be such that
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the shield wires shall hang in the Stringing blocks a minimum of 24 hours
before bringing up to final sag. After the 24 hour period has elapsed, the shield
wires shall be brought up to sag and clipped in within four (4) days. Wires
remaining in the blocks for more than 4 days shall be subject to inspection and
possible replacement at the Contractor’s expense if distortion of the conductor,
at the discretion of the Project Manager, has occurred.
j) The method and procedures used to string low tension spans or slack spans
to substation structures shall be such that the conductor is not permitted to
contact the ground or any object which may cause damage or otherwise
adversely affect the conductor. The method selected by the Contractor is
subject to the review and approval of the Project Manager prior to beginning
installation.
k) When stringing and sagging from angle structures, the Contractor shall
develop procedures that will compensate for structure deflections. All angle
poles and dead-end structures shall be plumbed straight or properly raked, as
specified in the applicable structure erection specification, after all shield wires
have been brought up to their proper sag-tension position and before clipping
in or dead-ending the shield wires. Swingout type angle structures shall be
clipped-in before at least the adjacent structures are clipped-in.
l) Conductors shall be spliced and dead-ended. There shall be not more than
one splice per conductor in any span and splices shall be located at least 3.5m
from the conductor support. Splices shall be installed in accordance with the
manufacturer's specifications and recommendations. All conductors shall be
cleaned thoroughly by wirebrushing before splicing or installing connectors or
clamps. A suitable inhibitor shall be used before splicing or applying
connectors over aluminum conductor.
m) No splices will be permitted in spans over main lines of roads, or over
communication lines. In other spans, only one splice per span will be
permitted on each wire, and this splice shall not be located closer than 15m to
any structure. Splices shall not be pulled through stringing sheaves or sagging
blocks.
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n) Connectors and hot-line clamps suitable for the purpose shall be installed as
shown on the drawings and also in accordance with the manufacturer's
specifications and recommendations. On all hot-line clamp installations, the
clamp and jumper shall be installed so that they are permanently bonded to
the load side of the line, allowing the jumper to be de-energized when the
clamp is disconnected.
5. LOW VOLTAGE NETWORK
In the rural villages of Santiago and FogoIslands to be electrified for first time a new
four wires low voltage, 230/400 V, overhead distribution network will be installed
wherever a new secondary substation is installed.
In the already electrified urban areas, near the new secondary substations or near
the existing ones the LV networks shall be expanded and/or reinforced.
The overhead network shall be made with self supportedAerial Bundled, aluminium
Cable in 8 or 10 meters wood poles.
In urban areas self supportedAerial Bundled, aluminium Cable in 8 or 10 meters
wood poles and underground cables connecting street fuse cabinets and wall
mounted fuse cabinets shall be installed. The trenches for underground cable
installation are indicated in the Drawing nº 0.0.20
All existing bare conductor shall be replaced by ABC cables.
As drop cable to connect the consumers to the grid it shall be used the new XS type
and the antitheft coaxial cable.
5.1. SCOPE OF WORK
In rural electrification the contractor is requested to design all LV distribution network
following Electra’s guides and/or recommendation and submit the detailed single line
diagrams to the employer’s representative for approval.
In case of expansion and/or reinforcement of existing LV Network in urban areas the
design shall be performed by employer and all single line diagrams will be gradually
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supplied to the contractor before starting the works according to his implementation
schedule.
It is foreseen the installation, extension and/or reinforcement of the following
networks:
In Santiago Island
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In Fogo Island
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In Maio Island
5.2. LV NETWORK EQUIPMENT SPECIFICATION
5.2.1. Cables
5.2.1.1. Non armored cable
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The cables shall have at least the following main characteristics:
VV2x2,5 VV3x2,5 VV2x10 VV 4x10
Type of cable VV VV VV VV
Standard 60502-1 60502-1 60502-1 60502-1
Voltage (kV) 0,6/1 0,6/1 0,6/1 0,6/1
Conductor
Material Cupper Cupper Cupper Cupper
Section (phase)-mm2 2,5 2,5 10 10
Section (neutral)-mm2 2,5 2,5 10 10
Number of wires per cond. 1 1 multi multi
Forma circular circular circular circular
Insulation
Material PVC PVC PVC PVC
Colour Black/Cyan Black/Cyan/Ground Black/Cyan
2xBlack/Marron
Cyan
Nominal thickness (mm) 0,8 0,8 1 1
Outer sheath
Material PVC PVC PVC PVC
Colour Black Black Black Black
Nominal thickness (mm) 1,8 1,8 1,8 1,8
Electric characteristics
Cond. Resit. at 20ºC - Ω/km 7,41 7,41 1,83 1,83
5.2.1.2. Armored cable for underground installation
LVAV4x50 LVAV 4x95 LVAV3x185+50
Type of cable LVAV LVAV LVAV
Standard 60502-1 60502-1 60502-1
Voltage (kV) 0,6/1 0,6/1 0,6/1
Conductor Material Aluminium Aluminium Aluminium
Section (phase)-mm2 50 95 185
Section (neutral)-mm2 50 95 95
Number of wires per cond. multi multi multi
Form sectorial sectorial sectorial
Insulation Material PVC PVC PVC
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Colour
2xBlack/Brown
Cyan
2xBlack/Brown
Cyan
2xBlack/Brown
Cyan
Nominal thickness (mm) 1,4 1,6 2
Mat. metallic armour ass PVC PVC PVC
Nominal thickness 1,2 1,3 1,5
Metallic armour
Material
Helicoidally
Iron tape
Helicoidally Iron
tape
Helicoidally
Iron tape
Minimum thickness 0,2 0,5 0,5
Outer sheath Material PVC PVC PVC
Colour Black Black Black
Nominal thickness (mm) 2 2,4 2,7
Electric characteristics
Cond. Resit. at 20ºC - Ω/km 0,64 0,32 0,164
5.2.1.3. Self-supportedAerial Bundled Cable for overhead network
LXS4x70+2x16 LXS4x35+16 XS4x6 XS2x6
Type of cable LXS LXS XS XS
Standard 60502-1 60502-1 60502-1 60502-1
Voltage (kV) 0,6/1 0,6/1 0,6/1 0,6/1
Conductor Material Aluminium Aluminium Cupper Cupper
Section (phase cond.)-mm2 70 2,5 6 6
Section (neutral cond.)-mm2 70 2,5 6 6
Section (Lighting cond)-mm2 16 16
Number of wires per cond. multi multi multi multi
Forma circular circular circular circular
Insulation XPLE XPLE XPLE XPLE
Colour Black Black Black Black
Nominal thickness (mm) 1,8 1,6 1,2 1,2
Electric characteristics
Cond. Resit. at 20ºC - Ω/km 0,443 0,868 3,08 3,08
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5.2.1.4. Anti-theft Cable
Cable concentric, anti-theft, 0,6/1 kV, for public LV network distribution, and
consumer drop.
The phasesconductors shall be in electrolytic bare cupper wires, stringing class
2(rigid), insulation in XLPE 90ºC,colours black, natural and red, filling with uPVC
compound and the neutral conductor shall be in electrolytic bare cupper wires
applied helically, concentric to phases with a polyester tape separator applied over
the conductor, insulation in XLPE black colour.
5.2.2. Supporting structures - Poles
5.2.2.1. Wood poles
The wood poles shall follow the French Standard NF C67-100 or at least an
equivalent one.
The poles shall have a circular cross-section and a conic profile with 8 and 10 m of
total length.
The trees used may have characteristics of adult wood. The poles shall be treated
with creosote or other efficient product according to the characteristics of the original
trees in order to preserve its longevity, but the preservative shall not reduce
significantly the dielectric strength of the wood.
The poles shall have a right axis. It is not acceptable that the line between the
centres of the cross sections limiting its useful length can come outside the pole
anywhere along its total length.
The pole portion to be undergrounded must have be prepared to offer resistance to
rain water penetration, with recourse to reinforced treatment, namely to be painted on
its underground portion and until 20 cm out of soil with an adequate thickness of
bituminous.
According to the mechanical strength, two types of poles can be used:
1. Wood pole 08/10 meters (type S325 or similar)
- maximum horizontal force at 0.25m from top: 3.25 kN
- minimal diameter on top (d) - 19 cm
- minimal diameter 1 m far from the bottom (D) - 25 cm
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2. Wood pole 08/10 meters (type S 550 or similar)
- maximum horizontal force at 0.25m from top: 5.5 kN
- minimal diameter on top (d) - 23 cm
- minimal diameter 1 m far from the bottom (D) – 29 cm
The measurement of the two diameters (d et D) shall be done after final surface
planning.
In some cases it is adopted the solution of double poles. When double poles
(geminated) are used, the union of both poles shall be done using hot deep
galvanized bolts, according to the French Standards each 2,5metrs.
It is requested in each pole the permanent inscription of:
supplier’s name;
impregnation treatment used ( according to French Standard, or equivalent );
year of fabrication;
total height (m);
maximum horizontal force;
Such inscriptions shall be made in a support made in material resistant to the
impregnation material.
5.2.3. Distribution Street Fuse Cabinet 230/400 V
The distribution Street Fuseboard Cabinet, 400/230 V shall be readyfor erection on a
concrete base or to be embedded
It shall have two parts:
A removable enclosure which shall house the equipment and which is fixed on
a basis structure.
A basis structure embedded or based on a concrete base.
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The following equipment shall be inside the enclosure:
triphase+ neutral copper busbars for 400A. The busbars shall have 20 MVA three
phase short circuit capacity.
2 triphasefuses holder size 2 located in the middle and 4 fuses holders size
00. The triphase fuses are disconnectableall together.
12 fuses size 00-160 A
6 fuses size 2-250 A
8 bimetallic compression lugs for two cables LVAV 3x185+95 mm2 shall be
bolted on the busbars and the neutral bar with stainless bolts.
24 bimetallic compression lugs for cables LVAV 4x50shall be bolted on the
outgoing phase connector and the neutral bar.
1earthing terminal block for earthing purposes and earthing of the cables
shielding.
1 fusehandle for installation and extraction of the 3 fuses all together.
The fixing bolts of the cabinet
The cabinet enclosureshall be in accordance with IEC standard 62208 and shallbe IP
54-11
It ismade with an insulating material, fire self-extinguishing, resistant and to the local
climate, especially to the saline atmosphere and the ultraviolet radiation. Natural air
cooling shall avoid any condensation or overheating.
It shall have approximately the following sizes:
height 875mm;
front width 800mm;
depth360 mm .
All the indoor equipment shall be boltedon a steel plate hot-galvanized or with an
equivalent corrosion treatment which resists to the saline atmosphere. This steel
plate shall be bolted on the basis structure in order to allow a fast removal and
replacement of the top enclosure without disconnecting the circuit which remains live.
Door shall have a large opening at least 120° and be removable without any tool. It
shall have an efficient lock by a triangle key (to be supplied). Means to keep
documents A4 shall be inside the enclosure.
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The basis structure is made in polyester with a mechanical resistance IK10 and shall
have the same size than the enclosure.
All the fixation bolts shall be supplied.
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5.2.4. Flush Mounted Fuse Cabinet 230/400 V
Flush-mounted fuse cabinets, 400/230 V, shall be supplied for the building
connection.
The enclosure shall be IP 41made in a moulded insulating material, fire self
extinguishing, resistant to local climate, in particular to saline air and ultraviolet
radiation, the mechanical resistance will be IK10.
The door shall be equipped with an efficient lock to be operated by a triangle
key.Closing and locking devices must be captive to be not lost.
The size shallbe:
height 420mm,
front width 285mm and
depth 180mm
It shall be equipped with;
3 fuse holders, size 00, for phase protection, and one neutral connecting bar
3 blade fuses type gl40 A
8 Bimetallic compression lugs and stainless bolts for the connection of 2
cables LVAV 4x50mm (bottom)
6 cuprum compression lugs and stainless bolts for the connection of 2 cables
VAV 4x10mm2
2 cables glands for 2 cables LVAV 3x50+25
on the cabinet bottom.
1 cables gland for 1 cables VAV 4x10mm2
on the cabinet top
1earthing terminal block for earthing
purposes and earthing of the cables shielding.
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1 handle to install or to remove
the fuse on its support if needed.
5.2.5. Luminary for wood pole installation
Luminary for wood pole mounting for 220 V, HP sodium lamps 70 W and 150W , with
polycarbonate prismatic diffuser type, having the optic compartment one protection
degree IP 66 and auxiliary compartment one protection degree IP 43 . The luminary
shall be fuse protected, be compensated for 0.9 power factor.
The cable connection between ABC line and auxiliary compartment will be a VV
2x2.5 mmcable. The length is 2.5 meters.
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Luminary shall be installed on the pole with a convenient arm as shown on the
drawing hereunder (only for example) and fixed on the wood pole witha stainless
strap. Anti rust primer marine coat paint
Ø Tube H α
42 1250 20º
5.2.6. Street light poles and Luminary for underground networks
The Street Light Polesshall be steel made, quality at least S275 JR – EN 100 25 – 2,
hot deep galvanized, according EN ISO 146, with anti rust primer marine coat
paint,once forming without slip joint, section taper round, conical profile, useful
height 10 m, fixation in the soil by burial, horizontal 150 W Lighting fixation on the
pole with a curve support, 1,75m length witch can be single or double as indicated in
the pictures below.On the underground portion and until 50 cm out of soil the poles
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shall be painted with an adequate thickness of bituminous painting, adherent to
galvanized structure. The supply includes a triphase cable connection boxe with fuse.
The contractor have to ensure that the support pipe Ød = 60 mm shallbe proper for
the installation of the 150 W luminary to be supplied on this scope.
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Ød = 60 mm / L1 = 1750 mm / R= 500 mm / H = 10 m
5.2.7. Energy meters
Supply of residential, sealable, static, single phase, single rate, active energy meters,
with direct readings in kWh, equipped of reinforced case covers able to support
penetration of metallic heated needles (with the objective to stop the operation of the
electromechanical kWh register). The meters shall have the accuracy class1, be
accurate for the frequency range of 50 Hz ±5% and shall follow IEC 62052-11 and
IEC 62053-25.
Single phase active energy meters 220 V (-20%, +15%), 5 (60) A
Single phase active energy meters 220 V (-20%, +15%), 10 (60) A
Supply, of commercial and industrial, sealable, static, single rate, active and reactive
energy meters, with direct readings in kWh and kVArh, equipped of reinforced case
covers able to support penetration of metallic heated needles (with the objective to
stop the operation of the electromechanical kWh register). The meters shall have the
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accuracy class1, be accurate for the frequency range of 50 Hz ±5% and shall follow
IEC 62052-11 and IEC 62053-25.
Three phase active and reactive energy meters, four wires, 3x220/380V
(-20%,+15%), 5 (60) A
Three phase active and reactive energy meters, four wires, 3x220/380 V
(-20%,+15%); 10 (60) A
The three phase active and reactive energy meters shall be equipped with a monthly
maximum active power demand indicator, readable by the client, with an integration
period of 15 minutes.
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6. SITE WORKS
6.1. SUPPLY AND WORKS UNDER CONTRACTOR RESPONSIBILITY
The Contractor will take the responsibility for the supplies and works mentioned in the
specification and priced in the price schedules, where the installation services price
must include the following:
Signaling and protection in the working areas.
The use of all tools, machinery’s, scaffolding, equipment and whatever else
necessary to carry out the contract jobs.
Installation of temporary passageways for pedestrian beside the trenches.
Supply and installation of iron plates with 1” (25,4mm) thickness on road
crossings.
Pumping of water from flooded trenches/ditches.
Request the Project Manager team, with at least 48 hours notice, for access to
ELECTRA premises.
6.2. PRELIMINARY MEASURES
Before starting the burying works, the Contractor must request from employer
information regarding the undergrounded facilities networks (electricity cables, water
and sewage pipes), telecommunication, etc…).
6.3. SIGNALLING AND PROTECTION
Contractor must install barriers and warning according to ELECTRA and government
requirements.
All work area including trenches and crossroads must be duly protected,
restricted and signalized, thus avoiding any accidents from the pedestrian and
the traffic.
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Protection must be carried out with barriers accepted by the Project Manager.
Contractor must take care of the day and night signals with no addition charge.
All working area must be signalized by yellow illuminated devices, and must
be visible from 30 meters.
Signaling lights must be fixed on barriers.
“flashingLamp” must be installed in both trench ends.
The signaling devices must be maintained until completion of the job.
On public roads the Contractor must use warning, directional and temporary
traffic signs with the colors and dimensions standardized by government and
in good conditions.
Contractor must repaint the horizontal traffic signs and re-install the supports
and vertical traffic signs, railings and metallic barriers in the same locations
with good condition after work completion with no additional charge.
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7. DRAWINGS
7.1. COMMON DRAWINGS
Common Drawings
Nº Designation Paper
FormatScale File Name
Civil drawings
0.0.01 Secondary substation 4x4 (1of2) A1 Esc : 1:50 Common 0.0.01.pdf
0.0.02 Secondary substation 4x4 (2of2) A1 Esc : 1:50 Common 0.0.02.pdf
0.0.03 Secondary substation Hexagonal (1of2) A1 Esc : 1:50 Common 0.0.03.pdf
0.0.04 Secondary substation Hexagonal (2of2) A1 Esc : 1:50 Common 0.0.04.pdf
0.0.05 Switching station 4x6 (Type A) (1of2) A1 Esc : 1:50 Common 0.0.05.pdf
0.0.06 Switching station 4x6 (Type A) (2of2) A1 Esc : 1:50 Common 0.0.06.pdf
0.0.07 Switching station 4x6 (Type B) (1of2) A1 Esc : 1:50 Common 0.0.07.pdf
0.0.08 Switching station 4x6 (Type B) (2of2) A1 Esc : 1:50 Common 0.0.08.pdf
0.0.09 Switching station 5x8 (Type A) (1of2) A1 Esc : 1:50 Common 0.0.09.pdf
0.0.10 Switching station 5x8 (Type A) (2of2) A1 Esc : 1:50 Common 0.0.10.pdf
0.0.11 Switching station 5x8 (Type B) (1of2) A1 Esc : 1:50 Common 0.0.11.pdf
0.0.12 Switching station 5x8 (Type B) (2of2) A1 Esc : 1:50 Common 0.0.12.pdf
0.0.13 Switching station 5x10 (Type A) (1of2) A1 Esc : 1:50 Common 0.0.13.pdf
0.0.14 Switching station 5x10 (Type A) (2of2) A1 Esc : 1:50 Common 0.0.14.pdf
0.0.15 Switching station 5x10 (Type B) (1of2) A1 Esc : 1:50 Common 0.0.15.pdf
0.0.16 Switching station 5x10 (Type B) (2of2) A1 Esc : 1:50 Common 0.0.16.pdf
0.0.17 Dimensions and equipment location - PUC up to 630 kVA A3 W/S Common 0.0.17.pdf
0.0.18 Door and metalic louvers A1 W/S Common 0.0.18.pdf
0.0.19 MV Trench profile A2 Esc : 1:2000 Common 0.0.19.pdf
0.0.20 LV Trench profile A4 Esc : 1:2000 Common 0.0.20.pdf
0.0.21 MV / LV Trench profile for street crossing A3 Esc : 1:2000 Common 0.0.21.pdf
0.0.22 Foundation for wood pole (single) (8, 10, 12) A3 W/S Common 0.0.22.pdf
0.0.23 Foundation for wood pole (twin) (8, 10, 12) A3 W/S Common 0.0.23.pdf
0.0.24 Twin pole (geminate poles) A3 W/S Common 0.0.24.pdf
0.0.25 Pole anchoring and counter pole top fitting slope A3 W/S Common 0.0.25.pdf
0.0.26 Pole guying MV / LV A3 W/S Common 0.0.26.pdf
0.0.27 Fixation and detail of assembly wooden structures (pórticos) A3 W/S Common 0.0.27.pdf
0.0.28 Crossarms for pin type insulator A4 W/S Common 0.0.28.pdf
0.0.29 Crossarms for suspension lines (NW) A4 W/S Common 0.0.29.pdf
0.0.30 Crossarms for string insulator A3 W/S Common 0.0.30.pdf
Single line Diagram (Switchboard)
0.1.31 Single line Diagram MV switchboard - Type 1 (RMU) A4 W/S Common 0.1.31.pdf
0.1.32 Single line Diagram MV switchboard - Type 2 (1 SD + 1 FSD) A4 W/S Common 0.1.32.pdf
0.1.33 Single line Diagram MV switchboard - Type 3 (1 DI + 1 FSD) A4 W/S Common 0.1.33.pdf
0.1.34 Single line Diagram MV switchboard - Type 4 (3 SD + 1 FSD) A4 W/S Common 0.1.34.pdf
0.1.35 Single line Diagram MV cubicles (FSD ; SD ; CB ) A3 W/S Common 0.1.35.pdf
0.1.36 Straight line pole mounted A3 W/S Common 0.1.36.pdf
0.1.37 Dead end pole mounted A3 W/S Common 0.1.37.pdf
0.1.38 Single line Diagram for LV Switchboard 250 A A3 W/S Common 0.1.38.pdf
0.1.39 Single line Diagram for LV Switchboard 1000 A A3 W/S Common 0.1.39.pdf
PTDSD Project: Part I - Rehabilitation,
Reinforcement and Expansion of MV and LV
Networks – LOT1 and LOT2
Vol III, lot 1 – Technical Specification and
Drawings
Page 147 of 150
7.2. SANTIAGO DRAWINGS
LOT 1 / Santiago List of Drawings
Nº Designation Paper
FormatScale File Name
7.0.01 General Plan of Santiago Island with Intervention areas A2 W/S Santiago 7.0.01.pdf
7.0.02 Single Line Diagram of Praia MV Network (Existing) A2 W/S Santiago 7.0.02.pdf
7.0.03 Single Line Diagram of Santiago Inland MV Network (Existing) A2 W/S Santiago 7.0.03.pdf
7.0.04 Single Line Diagram of Praia MV/HV Network (After PTDSD Project) A2 W/S Santiago 7.0.04.pdf
7.0.05 Single Line Diagram of Santiago Inland MV/HV Network (After PTDSD Project) A2 W/S Santiago 7.0.05.pdf
7.0.06 Single Line Diagram of Palmarejo Substation (Existing) A2 W/S Santiago 7.0.06.pdf
7.0.07 Single Line Diagram of Palmarejo Distribution Station A2 W/S Santiago 7.0.07.pdf
7.0.08 Single Line Diagram of Gamboa Substation (existing and future) A1 W/S Santiago 7.0.08.pdf
7.1.09 MV Underground line route Gamboa SS / Achada São Filipe 60/20kV SS 1/3 A1 1:2000 Santiago 7.1.09.pdf
7.1.10 MV Underground line route Gamboa SS / Achada São Filipe 60/20kV SS 2/3 A1 1:2000 Santiago 7.1.10.pdf
7.1.11 MV Underground line route Gamboa SS / Achada São Filipe 60/20kV SS 3/3 A1 1:2000 Santiago 7.1.11.pdf
7.1.12 MV Underground line route Achada Lem Ferreira / Achada Grande Trás A1 1:2000 Santiago 7.1.12.pdf
7.1.13MV Underground line route Tarrafal Sw. ST. / A. Baixo and Tarrafal Power
Station / M. Iria IIA1 1:2000 Santiago 7.1.13.pdf
7.1.14 MV Underground line route Chão Bom /Perdigoto and OHL/Cabeça Carreira A2 1:2000 Santiago 7.1.14.pdf
7.1.15 MV Underground line route Achada Fatima II A3 1:2000 Santiago 7.1.15.pdf
7.1.16 Single Line Diagram of São Filipe Switching Station A2 W/S Santiago 7.1.16.pdf
7.1.17 Single Line Diagram of Achada Grande Trás Switching Station A2 W/S Santiago 7.1.17.pdf
7.2.18 Route And Profile of Fontes Almeida / Mitra OHL 1/2 A1 1:500/1:2500 (V/H) Santiago 7.2.18.pdf
7.2.19 Route And Profile of Fontes Almeida / Mitra OHL 1/2 A1 1:500/1:2500 (V/H) Santiago 7.2.19.pdf
7.2.20 Route And Profile of João Teves and Varzea Igreja OHL(Upgrading do 20 kV)
1/2A1 1:500/1:2500 (V/H) Santiago 7.2.20.pdf
7.2.21 Route And Profile of João Teves and Varzea Igreja OHL(Upgrading do 20 kV)
1/2A1 1:500/1:2500 (V/H) Santiago 7.2.21.pdf
7.2.22 Route And Profile of Mercado Orgãos OHL(Upgrading to 20 kV) A2 1:500/1:2500 (V/H) Santiago 7.2.22.pdf
7.2.23 Route And Profile of Longueira OHL A2 1:500/1:2500 (V/H) Santiago 7.2.23.pdf
7.2.24 Route And Profile of Palhão OHL A2 1:500/1:2500 (V/H) Santiago 7.2.24.pdf
7.2.25 Route And Profile of Boca Larga and Montanhinha OHL (1/2) A1 1:500/1:2500 (V/H) Santiago 7.2.25.pdf
7.2.26 Route And Profile of Boca Larga and Montanhinha OHL (2/2) A1 1:500/1:2500 (V/H) Santiago 7.2.26.pdf
7.2.27 Route And Profile of Montanha OHL A2 1:500/1:2500 (V/H) Santiago 7.2.27.pdf
7.2.28 Route And Profile of Pedra Tcheu OHL A2 1:500/1:2500 (V/H) Santiago 7.2.28.pdf
7.2.29 Route And Profile of João Bom OHL A2 1:500/1:2500 (V/H) Santiago 7.2.29.pdf
7.2.30 Route and profile of Achada Carreira, Bimbirim and Gamxemba OHL-1/3 A1 1:500/1:2500 (V/H) Santiago 7.2.30.pdf
7.2.31 Route and profile of Achada Carreira, Bimbirim and Gamxemba OHL-2/3 A1 1:500/1:2500 (V/H) Santiago 7.2.31.pdf
7.2.32 Route and profile of Achada Carreira, Bimbirim and Gamxemba OHL-3/3 A1 1:500/1:2500 (V/H) Santiago 7.2.32.pdf
7.2.33 Route and profile of Mato Brasil / Achada Lagoa OHL-1/2 A1 1:500/1:2500 (V/H) Santiago 7.2.33.pdf
7.2.34 Route and profile of Mato Brasil / Achada Lagoa OHL-2/2 A1 1:500/1:2500 (V/H) Santiago 7.2.34.pdf
7.2.35 Route and profile of Chão da Silva and Maria Pereira OHL-1/3 A1 1:500/1:2500 (V/H) Santiago 7.2.35.pdf
7.2.36 Route and profile of Chão da Silva and Maria Pereira OHL-2/3 A1 1:500/1:2500 (V/H) Santiago 7.2.36.pdf
7.2.37 Route and profile of Chão da Silva and Maria Pereira OHL-3/3 A1 1:500/1:2500 (V/H) Santiago 7.2.37.pdf
7.2.38 Route and profile of Achada BelBel OHL A1 1:500/1:2500 (V/H) Santiago 7.2.38.pdf
7.2.39 Route and profile of Monte Negro OHL A1 1:500/1:2500 (V/H) Santiago 7.2.39.pdf
7.2.40 Route and profile of Boca Ribeira / Achada Garçote OHL A1 1:500/1:2500 (V/H) Santiago 7.2.40.pdf
7.2.41 Route and profile of Hortelã / ChaCha OHL A2 1:500/1:2500 (V/H) Santiago 7.2.41.pdf
7.2.42 Route and profile of Leitões / Burbur OHL A2 1:500/1:2500 (V/H) Santiago 7.2.42.pdf
7.2.43 Route and profile of Lém Rua OHL A2 1:500/1:2500 (V/H) Santiago 7.2.43.pdf
7.2.44 Route and profile of Charco and Achada Leite OHL -1/2 A1 1:500/1:2500 (V/H) Santiago 7.2.44.pdf
7.2.45 Route and profile of Charco and Achada Leite OHL -2/2 A1 1:500/1:2500 (V/H) Santiago 7.2.45.pdf
7.2.46 Route And Profile of Santana / (Pole 57) Belém OHL -1/2 A2 1:500/1:2500 (V/H) Santiago 7.2.46.pdf
7.2.47 Route And Profile of Santana / (Pole 57) Belém OHL -2/2 A2 1:500/1:2500 (V/H) Santiago 7.2.47.pdf
PTDSD Project: Part I - Rehabilitation,
Reinforcement and Expansion of MV and LV
Networks – LOT1 and LOT2
Vol III, lot 1 – Technical Specification and
Drawings
Page 148 of 150
LOT 1 / Santiago List of Drawings
Nº Designation Paper
FormatScale File Name
7.2.48 Route and Profile of P1(57) Belém, Tronco and Pico Leão OHL 1/3 A1 1:500/1:2500 (V/H) Santiago 7.2.48.pdf
7.2.49 Route and Profile of P1(57) Belém, Tronco and Pico Leão OHL 2/3 A1 1:500/1:2500 (V/H) Santiago 7.2.49.pdf
7.2.50 Route and Profile of P1(57) Belém, Tronco and Pico Leão OHL 3/3 A1 1:500/1:2500 (V/H) Santiago 7.2.50.pdf
7.1.51 MV Underground line route Palmarejo Power Station / New Palmarejo 20 kV
Distribution StationA1 1:500 Santiago 7.1.51.pdf
7.1.52 Gamboa Distribution Station Building A1 1:100 Santiago 7.1.52
7.3.53 Areas for Rehabilitation and Expansion of LV Network in Praia City A1 1:10000 Santiago 7.3.53.pdf
7.3.54 Areas for Rehabilitation and Expansion of LV Network in Ribeira Grande A1 1:2500 Santiago 7.3.54.pdf
7.3.55 Areas for Rehabilitation and Expansion of LV Network in Orgãos (1/2) A2 1:2500 Santiago 7.3.55.pdf
7.3.56 Areas for Rehabilitation and Expansion of LV Network in Orgãos (2/2) A1 1:2500 Santiago 7.3.56.pdf
7.3.57 Areas for Rehabilitation and Expansion of LV Network in São Domingos A2 1:2500 Santiago 7.3.57.pdf
7.3.58 Areas for Rehabilitation and Expansion of LV Network in Tarrafal (1/2) A2 1:2500 Santiago 7.3.58.pdf
7.3.59 Areas for Rehabilitation and Expansion of LV Network in Tarrafal (2/2) A1 1:2500 Santiago 7.3.59.pdf
7.3.60 Areas for Rehabilitation and Expansion of LV Network in Santa Cruz A1 1:2500 Santiago 7.3.60.pdf
PTDSD Project: Part I - Rehabilitation,
Reinforcement and Expansion of MV and LV
Networks – LOT1 and LOT2
Vol III, lot 1 – Technical Specification and
Drawings
Page 149 of 150
7.3. FOGO DRAWINGS
LOT 1 / Fogo List of Drawings
Nº Designation Paper
FormatScale File Name
8.0.01 PTDSD Project Acting areas in Fogo Island A2 W/S Fogo 8.0.01.pdf
8.0.02 Implantation of Fogo MV Network (Includes ORET and PTDSD Project) A2 W/S Fogo 8.0.02.pdf
8.0.03 Single line Diagram of Fogo MV Network (Includes ORET and PTDSD Project) A2 W/S Fogo 8.0.03.pdf
8.1.04 MV Underground line route Achada S Filipe / Fonte Aleixo A2 1:2000 Fogo 8.1.04.pdf
8.1.05 MV Underground line route Fonte Aleixo / Patim OHL A2 1:2000 Fogo 8.1.05.pdf
8.1.06 MV Underground line route Congresso / Xaguate A2 1:2000 Fogo 8.1.06.pdf
8.1.07 MV Underground line route Mosteiros Trás II A2 1:2000 Fogo 8.1.07.pdf
8.1.08 Single Line Diagram of Patim Switching Station A3 W/S Fogo 8.1.08.pdf
8.1.09 Single Line Diagram of Ponta Verde Switching Station A3 W/S Fogo 8.1.09.pdf
8.1.10 Single Line Diagram of Xaguate Switching Station A3 W/S Fogo 8.1.10.pdf
8.1.11 Single Line Diagram of Cova Figueira Switching Station A3 W/S Fogo 8.1.11.pdf
8.2.12 Route and profile of São Filipe / Patim OHL-1/5 A1 1:500/1:2500 (V/H) Fogo 8.2.12.pdf
8.2.13 Route and profile of São Filipe / Patim OHL-2/5 A1 1:500/1:2500 (V/H) Fogo 8.2.13.pdf
8.2.14 Route and profile of São Filipe / Patim OHL-3/5 A1 1:500/1:2500 (V/H) Fogo 8.2.14.pdf
8.2.15 Route and profile of São Filipe / Patim OHL-4/5 A1 1:500/1:2500 (V/H) Fogo 8.2.15.pdf
8.2.16 MV supply feeder Route of S.Filipe Patim OHL Derivations Profiles 5/5 A1 1:500/1:2500 (V/H) Fogo 8.2.16.pdf
8.2.17 Route and profile of Patim / Socorro OHL-1/2 A1 1:500/1:2500 (V/H) Fogo 8.2.17.pdf
8.2.18 Route and profile of Patim / Socorro OHL-2/2 A1 1:500/1:2500 (V/H) Fogo 8.2.18.pdf
8.2.19 Route and profile of Cidreira OHL A1 1:500/1:2500 (V/H) Fogo 8.2.19.pdf
8.2.20 Route and profile of Achada Fora OHL A1 1:500/1:2500 (V/H) Fogo 8.2.20.pdf
8.2.21 Route and profile of Cabeça Fundão OHL - 1/3 A2 1:500/1:2500 (V/H) Fogo 8.2.21.pdf
8.2.22 Route and profile of Cabeça Fundão OHL - 2/3 A1 1:500/1:2500 (V/H) Fogo 8.2.22.pdf
8.2.23 Route and profile of Cabeça Fundão OHL - 3/3 A1 1:500/1:2500 (V/H) Fogo 8.2.23.pdf
8.2.24 Route and profile of M. Gonçalves Cutelo Capado OHL - 1/3 A1 1:500/1:2500 (V/H) Fogo 8.2.24.pdf
8.2.25 Route and profile of M. Gonçalves Cutelo Capado OHL - 2/3 A1 1:500/1:2500 (V/H) Fogo 8.2.25.pdf
8.2.26 Route and profile of M. Gonçalves Cutelo Capado OHL - 3/3 A2 1:500/1:2500 (V/H) Fogo 8.2.26.pdf
8.2.27 Route and profile of Forno OHL A3 1:500/1:2500 (V/H) Fogo 8.2.27.pdf
8.2.28 Route and profile of Patim / Monte Grande OHL - 1/2 A1 1:500/1:2500 (V/H) Fogo 8.2.28.pdf
8.2.29 Route and profile of Patim / Monte Grande OHL - 2/2 A2 1:500/1:2500 (V/H) Fogo 8.2.29.pdf
8.3.30 São Filipe City General View A2 1:5000 Fogo 8.3.30.pdf
8.3.31 São Filipe LV Network diagram 1/5 (Xaguate) A2 (Exten.) 1:2000 Fogo 8.3.31.pdf
8.3.32 São Filipe LV Network diagram 2/5 (Down Town) A2 1:2000 Fogo 8.3.32.pdf
8.3.33 São Filipe LV Network diagram-Street Lighting 3/5 (Down Town) A2 1:2000 Fogo 8.3.33.pdf
8.3.34 São Filipe LV Network diagram 4/5 (Achada São Filipe) A2 1:2000 Fogo 8.3.34.pdf
8.3.35 São Filipe LV Network diagram 5/5 (Congresso) A2 1:2000 Fogo 8.3.35.pdf
PTDSD Project: Part I - Rehabilitation,
Reinforcement and Expansion of MV and LV
Networks – LOT1 and LOT2
Vol III, lot 1 – Technical Specification and
Drawings
Page 150 of 150
7.4. MAIO DRAWINGS
LOT 1 / Maio List of Drawings
Nº Designation Paper
FormaScale File Name
6.0.01 General Plan of Maio Island with Intervention areas A2 W/S Maio 6.0.01.pdf
6.0.02 Single Line Diagram of Maio MV Network (Existing) A2 W/S Maio 6.0.02.pdf
6.0.03 Single Line Diagram of Maio MV Network (After PTDSD Project) A2 W/S Maio 6.0.03.pdf
6.0.04 Single Line Diagram of Torril Substation (Existing) A3 W/S Maio 6.0.04.pdf
6.1.05 MV Underground line route Torril Power Station / Ponta Preta and C Formação A2 1:2000 Maio 6.1.05.pdf
6.1.06 MV Underground Line route in Porto Inglês City (DownTown) expansion Area A2 1:2000 Maio 6.1.06.pdf
6.1.07 MV Underground line route Farol / Fontona A2 1:2000 Maio 6.1.07.pdf
6.1.08 MV Underground line route Fontona / Aeroporto A1 1:2000 Maio 6.1.08.pdf
6.1.09 MV Underground line route Aeroporto / Curralona A1 1:2000 Maio 6.1.09.pdf
6.1.10 MV Underground line route Curralona / Morro A2 1:2000 Maio 6.1.10.pdf
6.1.11 MV Underground line route Curralona / Bela Vista A2 1:2000 Maio 6.1.11.pdf
6.1.12 MV Underground line route Morro / Calheta OHL A2 1:2000 Maio 6.1.12.pdf
6.1.13 MV Underground line route Morro OHL / Calheta /Morrinho OHL A2 1:2000 Maio 6.1.13.pdf
6.1.14 MV Underground line route Calheta OHL / Morrinho S/S A3 1:2000 Maio 6.1.14.pdf
6.1.15 Single Line Diagram of Fontona Switching Station A3 W/S Maio 6.1.15.pdf
6.1.16 Single Line Diagram of Curralona Switching Station A3 W/S Maio 6.1.16.pdf
6.1.17 Single Line Diagram of Morro Switching Station A3 W/S Maio 6.1.17.pdf
6.1.18 Single Line Diagram of Pedro Vaz Switching Station A3 W/S Maio 6.1.18.pdf
6.2.19 Route and profile of Figueira Seca / Alcatrás OHL-1/3 A1 1:500/1:2500 (V/H) Maio 6.2.19.pdf
6.2.20 Route and profile of Figueira Seca / Alcatrás OHL-2/3 A1 1:500/1:2500 (V/H) Maio 6.2.20.pdf
6.2.21 Route and profile of Figueira Seca / Alcatrás OHL-3/3 A1 1:500/1:2500 (V/H) Maio 6.2.21.pdf
6.3.22 Line Route of Morro / Morrinho OHL to be Rehabilitaded 1/2 A1 1:2500 Maio 6.3.22.pdf
6.3.23 Line Route of Morro / Morrinho OHL to be Rehabilitaded 2/2 A1 1:2500 Maio 6.3.23.pdf
6.3.24 Line Route of Pedro Vaz / Alcatraz OHL to be Rehabilitaded 1/2 A1 1:2500 Maio 6.3.24.pdf
6.3.25 Line Route of Pedro Vaz / Alcatraz OHL to be Rehabilitaded 2/2 A1 1:2500 Maio 6.3.25.pdf
6.4.26 Porto Inglês LV Network diagram (Zona Fontona) - (1/4) A2 1:2000 Maio 6.3.26.pdf
6.4.27 Porto Inglês LV Network diagram (Farol Cemitério) - (2/4) A2 1:2000 Maio 6.3.27.pdf
6.4.28 Porto Inglês LV Network diagram (Ponta Preta) - (3/4) A2 1:2000 Maio 6.3.28.pdf
6.4.29 Porto Inglês LV Network diagram (Torril) - (4/4) A2 1:2000 Maio 6.3.29.pdf
6.4.30 Morro LV Network diagram A2 1:2000 Maio 6.3.30.pdf
6.4.31 Calheta LV Network diagram A1 1:1500 Maio 6.3.31.pdf
6.4.32 Morrinho LV Network diagram A3 1:2000 Maio 6.3.32.pdf
6.4.33 Cascabulho LV Network diagram A3 1:1000 Maio 6.3.33.pdf
6.4.34 Pedro Vaz LV Network diagram A3 1:1500 Maio 6.3.34.pdf
6.4.35 Alcatraz LV Network diagram A3 1:1000 Maio 6.3.35.pdf
6.4.36 Pilão Cão LV Network diagram A3 1:1000 Maio 6.3.36.pdf