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TECHNICAL SPECIFICATION
FOR 33 kV & 11 kV INDOOR SWITCHGEAR UNITS
Contents
1.1 General ..................................................................................................................................................... 3
1.2 Codes and Standards ................................................................................................................................. 3
1.4 Specific Requirements ............................................................................................................................... 6
This specification is intended to cover the [design, engineering, manufacture, assembly,
testing at manufacturer's works, supply in properly packed condition for transport to site,
erection, site testing and commissioning] of 33 kV & 11 kV indoor Switchgear.
The system shall be complete in all respect including all accessories required for efficient
and trouble-free operation of Ranchi Smart City, Jharkhand.
1.2 Codes and Standards
All equipment and materials shall be designed, manufactured and tested in accordance with
the latest applicable Indian Standards (IS) / IEC as given below except where modified and/or
supplemented by this specification.
Table 1.0
Codes Name of Standard
IS : 226 Structural steel ( standard quality)
IS : 375 Switchgear bus bars, main connections and auxiliary wiring, marking and
arrangement
IS :722 AC electricity meters
IS : 728 Galvanized steel structures
IS : 2099 Specification for bushings for alternating voltages above 1000 volts
IS : 2147 Degree of protection
IS : 2516 Alternating current circuit breakers
IS : 2544 Specification for porcelain post insulators for systems with nominal voltages
greater than 1000 volts
IS : 2705 Current transformer specification
IS : 3043 Code of practice for earthing
IS : 3156 voltage transformers specification
IS : 3231 specification for electrical relays for power system protection
IS : 3427 A.C. metal enclosed switchgear and control gear for rated voltages above 1 kV
and up to and including 52 kV.
IS : 4710 Switches and switch isolators above 1000 V but not exceeding 11000 V.
IS : 5082 Specification for wrought aluminum and aluminum alloy bars, rods, tubes and
selections for electrical purposes.
IS : 6875 Control switches push buttons
IS : 8084 Specification for interconnecting bus-bars for ac voltage above 1 kV up to and
including 36 kV
IS : 8686 Specification for static protective relays
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
3
Codes Name of Standard
IS : 9046 Specification for ac contactors for voltages above 1000 V up to and including
11 000 V
IS : 9224 Low voltage fuses
IS : 9385 HV fuses
IS :9431 Specification for indoor post insulators of organic material for
system with nominal voltages greater than 1000 volts upto and
including 300 kV
IS : 9921 Alternating current disconnectors (isolators) and earthing switches for
voltages above 1000 V
IS : 10601 Dimensions of terminals of high voltage switchgear and control gear
IS : 11353 Guide for uniform system of marking and identification of
Conductors and apparatus terminals.
IS : 13118 Specification for high voltage ac circuit breakers
IEC 6044-1 Current transformer
IEC 6044-2 Voltage transformer
IEC 6056 High voltage alternating current circuit breakers
IEC-60099-1 Non-linear resistor type gapped arrestor for AC systems
IEC-60099-4 Metal oxide surge arrestor without gap for AC system
IEC 60129 A.C. disconnectors and earthing switches
IEC 60255 Electrical Relays
IEC-60298 High voltage metal enclosed switchgear and control gear.
IEC 60529 Degrees of protection provided by enclosures
IEC-62271-100 High voltage alternating current circuit breakers.
CEA CEA regulations
Equipment and material conforming to any other standard which ensures equal or better
quality may be accepted. In such case, copies of the English version of the standard adopted
shall be submitted along with the bid.
The electrical installation shall meet the requirements of Indian Electricity Rules as amended
up to date and relevant IS Code of Practice. In addition, other rules and regulations applicable
to the work shall be followed.
1.3 Design Criteria
a. All 33kV & 11kV Switchgear shall be suitable for an ambient temperature of 45 °C and
relative humidity of 87%. The Switchgear shall be suitable for operation in a highly
polluted environment.
b. All 33kV & 11kV Switchgear shall be suitable for following voltage & frequency variations
as follows:
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
4
Voltage Variation : (±) 10%
Frequency Variation : (+) 3% to (-)5%
Combined Variation of Voltage &
Frequency
: 10% (absolute sum)
For DC System : (+)10% to (-)15%
c. Motor rated [160-600kW] shall be provided with [vacuum contactor/vacuum circuit
breaker] and motor rated above [600kW] shall be provided shall be provided with
vacuum circuit breakers.
d. 33kV & 11kV switchgear shall be Indoor, metal clad, floor mounted, Single front and fully
draw out type. Design and construction shall be such as to allow extension at either end.
These shall be Aluzinc/ CRCA sheet metal enclosed and assembled to form a rigid, free-
standing floor mounted structure. Vertical units shall be assembled to form a continuous
line up of panels
e. All 33kV & 11kV Circuit breaker shall be draw out type & should have Service, Test and
Disconnected positions with positive indications for service & test positions. It shall be
possible to charge the springs manually, if, required
f. Local/remote selection shall be provided for all incoming/Outgoing Circuit Breaker
modules. Incoming/Outgoing breaker shall be closed at service position from remote
(SCADA placed at MRSS) and at test position from Local (Switchgear).
g. Control and Indication voltage level shall be 110V DC.
h. Maximum system fault level at 33kV & 11kV buses shall be 26.2kA for 1 sec & 18.3kA for
1 sec respectively. Switchgear should be rated for Internal arc rating for 33kv, 26.2kA for
1Sec & 11kv, 18.3kA for 1Sec. Switchgear should be tested for Breaker, Cable and Busbar
chamber for AFLR IAC for 1Sec.
i.
j. 33kV & 11kV System shall be solidly earthed.
k. Surge arrestor shall be provided for each Transformer feeder.
l. The switchgear will be located in a clean but hot humid and tropical atmosphere.
m. For continuous operation at specified ratings, temperature rise of the various switchgear
components shall be limited to the permissible values stipulated in the relevant
standards and this specification.
n. The switchgear and components thereof shall be capable of withstanding the mechanical
forces and thermal stresses of the short circuit current without any damage or deterioration of material.
o. All the numerical relays shall have communication on two ports, local front port
communication to laptop and a second port with [IEC 61850 protocol] to communicate
with SCADA placed at MRSS.
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
5
1.4 Specific Requirements
1.4.1 Construction
All 33kV & 11kV switchgear shall have following minimum features.
a. 33kV & 11kV switchgear shall be of indoor, metal clad, single front, single tier, floor
mounted, horizontal drawout type with vacuum circuit breaker and free standing type.
The Panels shall be suitable for cable entry at bottom and bus duct connection at top.
b. Cable is considered between 33kV/11kV switchgear incomer and transformer. Hence
switchgear shall be suitable for this connection.
c. All frames and load bearing members shall be fabricated using mild steel structural
sections or pressed and shaped cold rolled sheet steel of thickness not less than 2 mm.
d. Frame shall be enclosed in cold rolled sheet steel of thickness not less than 2 mm. Doors
and Covers shall also be of cold rolled sheet steel of thickness not less than 1.6 mm.
Removable gland plates of thickness 3mm (hot/cold rolled sheet steel) or 4 mm (non
magnetic material )shall be provided for all panels. Suitable removable type lifting hooks
and / or jacking pad shall be provided on each panel or shipping section for ease of lifting
of switchgear. These hooks when removed shall not leave any opening in the panels.
e. Each breaker shall be housed in a separate cubicle, complete with an individual front
access door. Each vertical section shall have a removable back cover. The vacuum-
interrupter, circuit-breaker and the switchgear panel shall be of the same make.
f. The switchgear enclosure shall confirm to the degree of Protection of the IP-42 for indoor
installation. However degree of protection of LV chamber shall be IP-52. No
louvers/Opening shall be provided on the top of panel. All the other louvers if provided
shall have very fine brash or GI mesh screen.
g. Paint shade for complete panels shall be [RAL 7032] for extreme end covers for all board.
h. The working zone shall be restricted to [750mm to 1800mm] from floor level. Total
height of the switchgear panels shall not exceed [2600 mm].
i. Metallic barriers shall be provided between vertical sections and also between adjacent
modules to ensure prevention of accidental contact with live parts during routine
inspection/maintenance of functional units or cable terminations of one or more
functional units when working on those of adjacent units. These barriers shall have
insulating inserts as necessary for taking the interconnections etc.
j. A nameplate with switchgear designation shall be fixed at the top of the central panel. A
separate nameplate giving feeder details shall be provided for each compartment. A
separate nameplate giving details of bus section shall also be provided for switchgear
having more than one bus section.
k. Name plate shall be provided for each equipment (lamps, push buttons, switches, relays,
auxiliary contactor, etc) mounted on the switchboard. Special warning plates one each on
each feeder of a shipping section shall be provided on removable covers of doors giving
access to cable terminals and busbars. Name plate size shall be minimum of 20x75 mm
for Instruments/devices and 40x50 mm for panels. Thickness shall be minimum 3 mm.
l. Two 110V DC feeders shall be provided for control, Indication and annunciation of
breaker operated module at any one cubicle. Further distribution to all verticals shall be
in the scope of bidder.
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
6
m. Compartment door shall be interlocked with main power isolating device for safety with
provision for defeating it by authorized person.
n. Supplier shall provide total 10% or minimum one (1) no. spare feeder of each type &
rating with respect to total requirement of the switchgear.
o. Switchgear shall have provision to receive Single phase 240V Each cubicle shall be
provided with thermostat controlled space heaters suitable for operation from 240 V ±
10%, single phase, 50 Hz, + 3% - 5% supply and 5A, 240V AC, 3 pin plug socket and cubicle
lamp. The space heaters shall be located at the bottom of the switchboards. Cubicle
heater, plug/socket/lamp circuits shall have individual switch fuse units. Motors shall be
provided with anti- condensation heaters at 240V.Necessary provision for supply of
motor space heating shall be considered in the switchgear.
p. All relays, meters, switches and lamps shall be flush mounted on the respective cubicle
door or on control cabinet built on the front of the cubicle.
q. Controls and interlocks as required for the safe switching, operation and maintenance of
the switchgear shall be provided. Mechanical interlocks shall be provided in addition to
electrical wherever possible.
r. It should be possible to carryout maintenance on a feeder with adjacent feeders alive.
s. The switchgear shall be [natural/ gas cooled].
t. The circuit breakers, contactors, bus VTs shall be mounted on withdrawable truck which
shall roll out horizontally from service position to isolated position.
1.4.2 Bus and Bus Taps
a. The main buses and connections shall be of high conductivity aluminum .Control
and auxiliary buses shall be of electrolytic copper/copper wires.
b. Bus bars and connections shall be fully insulated for working voltage with
adequate phase / ground clearances. Insulating sleeves for bus bars and shrouds
for joints shall be provided.
c. Bus insulator shall be flame-retardant, non-hygroscopic, track resistant type with
high creepage surface. This shall be of non-carbonizing material such as epoxy
bonded fiberglass. Bus bars shall be color coded for easy identification. Standard
type tested design without bus support insulator is also acceptable.
d. The bus bar supports shall be able to withstand stresses due to maximum short
circuit and also take care of any thermal expansion.
e. Bus bars shall be color coded for easy identification and so located that the
sequence R-Y-B shall be from left to right, top to bottom or front to rear, when
viewed from the front to switchgear assembly.
f. The continuous rating of the main bus bars shall be same as that of the incomer
circuit breaker and shall carry this continuous current without exceeding the
temperature of [90 °C]. For silver plated joints maximum temperature shall be
limited to [105 °C] inline with IEC standard.
g. The busbar chamber shall be provided with inter panel barrier with epoxy cast
seal off bushings through which the buses will pass through so as to prevent fire
from one panel to another.
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
7
1.4.3 Circuit Breaker
a. The circuit breaker shall be of vacuum type.
b. The circuit breakers shall be fully draw-out type, having service, test and disconnected
positions with positive indicators for service & test positions.
c. The breakers shall have motor operated spring charged mechanism. It shall be possible
to charge the springs manually, if, required. Breakers shall be trip free and shall have an
anti-pumping device. The operating duty cycle shall be 0 -0.3 sec-CO-3 min.-CO.
d. For motor, spring charging shall take place automatically after each breaker closing
operation. One open-close-open operation of the circuit breaker shall be possible after
failure of power supply to the motor.
e. Automatic safety shutters shall be provided to ensure the inaccessibility of live parts
after the breaker is drawn out. There shall be distinct overall door for the breaker
compartment and shall be lockable.
f. Truck shall have distinct service, Test and Isolated positions. It shall be possible to close
the breaker compartment door in isolated position also. The truck and breaker frame
shall get earthed while the truck is being inserted in the panel and positive earthing of
the truck and breaker frame shall be maintained in all positions.
g. Outgoing breakers shall be suitable for switching transformers and motors at any load.
h. Mechanical safety interlocks shall be provided to prevent
i. The circuit breaker from being racked in or out of the service position when the
breaker is closed.
ii. Racking in the circuit breaker unless the control plug is fully engaged
i. Breakers shall be adequately de-rated to account for design ambient temperature and
temperature inside the cubicle.
j. Equipment and component rating and quantities shall be suitably selected according to
the requirements with adequate margin.
k. Closing and tripping coil shall operate satisfactorily under the following conditions.
i. Closing Coil: 85% to 110% of rated voltage.
ii. Tripping Coil : 70% to 110% of rated voltage
Closing coil and tripping coil must be rated for continues current and interchangeable.
1.4.4 Contactor
High voltage contactor shall be of AC-3 utilization category and shall be of vacuum type.
Fuse and contactor shall be mounted on withdrawable truck. The contactor shall be
latched type and shall be complete with mechanical trip indicator, anti pumping relay,
surge suppresser, single phasing preventor etc.
1.4.5 Current Transformers
a. Current Transformers shall be cast-resin type. All secondary connections shall be
brought out to terminal blocks where wye or delta connection shall be made. They shall
have sufficient thermal and mechanical capacity to withstand the maximum momentary
current rating of the breakers.
b. CTs shall have polarity makings indelibly marked on each transformer at the lead
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
8
terminations and at the associated terminal block. Facility shall be provided for short
circuiting and grounding the CT secondary at the terminal blocks. Secondary terminals
shall be provided with protective cap.
c. CT terminal block shall be disconnecting type and suitable for round type lugs with
facility for testing and short circuiting of individual CT.
d. All CTs shall be provided with supports independent of busbars / busbar supports. The
CTs shall be located in such a way that they can be easily approached for maintenance
without necessitating shutdown of adjacent feeders.
e. CTs shall be provided with disconnected type test links in both secondary leads for
carrying out current and phase angle measurement.
f. Accuracy class of CT shall be 5P20 for protection, PS for differential protection and 0.2
for incomer & 1.0 for outgoing metering.
g. CT VA shall be as per design requirement.
1.4.6 Voltage Transformer
a. Voltage transformers (VT) shall be cast-resin type with an accuracy class of 0.2 for line
metering & 0.5 for bus metering and 3P for protection.
b. VTs shall be of the single-phase type. VTs shall be protected on their primary side by fuse
and by MCB (with auxiliary contacts) on the secondary sides.
c. It shall be possible to replace VTs without having to de-energise the main busbars.
d. VTs shall be provided with disconnected type test links in both secondary leads for
carrying out current and phase angle measurement.
1.4.7 Secondary wiring
a. The switchgear shall be fully wired at the factory to ensure proper functioning of
control, protection and interlocking schemes.
b. Fuse and links shall be provided to permit individual circuit isolation from bus wires
without disturbing other circuits. All spare contacts of relays, switches and other devices
shall be wired up to terminal blocks.
c. Secondary wiring within the switchgear shall be carried out in a neat and systematic
manner and securely held in position (either loomed or run in conduit / trunking).
Wherever wiring passes through compartment, it shall be run in conduit / trunking, if
metallic shall be bonded to the main earth busbar.
d. Wiring shall be done with flexible, 1.1/0.650kV grade, PVC insulated switchboard wires
with stranded copper conductors of 2.5 mm2 for CT & PT circuits and 1.5mm2 for
control circuit wiring (applicable for internal panel wiring).
e. Each wire shall be identified, at both ends, with permanent markers bearing wire
numbers as per bidder s wiring diagrams. Wire terminations shall be made with
crimping type connectors with insulating sleeves, wire shall not be spliced between
terminals.
1.4.8 Terminal blocks
a. Terminal blocks shall be of 1100 V grade, stud type with marking strips. Terminals for CT
secondary leads shall have provision for easy shorting, earthing and shall be suitable for
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
9
connecting 2 cables of 2.5 mm2 copper.
b. Sufficient terminals shall be provided on each terminal block to ensure that not more
than two outgoing wires are connected per terminal. All spare contacts of auxiliary
relays, timers etc. shall be wired up to the terminals. 20% spare terminals shall be
provided on each terminal block.
c. Terminal blocks shall be located to allow easy access. Wiring shall be grouped such that
the individual wires of a cable can be connected to consecutive terminals.
1.4.9 Ground bus
a. A ground bus, rated to carry maximum fault current, shall extend full length of the
switchgear. The ground bus shall be provided with two-bolt drilling with G.I. bolts and
nuts at each end to for connection to the grounding conductor / flat.
b. Each unit shall be connected directly to the ground bus. The frame of each circuit
breaker and draw out V.T. unit shall be grounded through heavy multiple contacts at all
times except when the primary disconnecting devices are separated by a safe distance.
c. C.T. & V.T. secondary neutrals shall be earthed through removable links so that earth of
one circuit may be removed without disturbing others. All hinged doors shall be
earthed by flexible copper bride.
1.4.10 Control & Indication
a. The circuit breaker shall be wired up for local & remote operation. Each breaker shall
be equipped with following:
b. Remote selector switch with pistol grip handle and key interlock for breakers with
motor wound spring charging mechanism. In Remote position, the breaker can be
operated in service position with all interlock and protections. In Local position, the
breaker shall be operated from switchgear only in test position.
c. Each cubicle shall be provided with Auto/ Manual Switch. Trip selection switch and
Trip-Neutral- Close (TNC) switch.
d. Circuit breaker shall be indicated electrically. The following indication color shall be
used.
Breaker closed – Red
Breaker opened – Green
Spring Charged – White
Breaker Auto trip – Amber
e. However any other indication shall be provided as per owner s requirements.
f. Lamps shall be LED type with resistance for voltage protection. Lamp and lens shall be
replaceable from the front.
g. Breakers shall be controlled locally and/or remotely as per plant operational
requirement. Necessary Interposing relays & feedback signal shall be provided based
on the SCADA, placed at MRSS, IO list.
h. Breaker control supply shall be of 110 V DC. Breaker spring charging motor shall be
suitable for 240V AC.
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
10
1.4.11 Cable termination
Switchgear shall be designed for cable entry from the bottom. Sufficient space shall be
provided for ease of termination and connection.
1.4.12 Painting
All sheet steel surfaces shall be chemically cleaned, degreased and pickled in acid to produce a
smooth, clean surface free of scale, grease and rust. After cleaning, the surface shall be given
a phosphate coating followed by a coat of high quality primer and baking in the oven.
The paint shade shall be subject to owner s approval. Sufficient quantity of touch up paint
shall be furnished for application at site.
1.4.13 Relays, Protection & Metering
a. The hardware design for protection and associated equipment shall use latest state–of–the-art technology and shall generally be integrated numerical/digital, modular in
nature. Where design is based on numerical technology, adequate self
testing/monitoring/ diagnostic facilities shall be provided.
b. All numerical relays, auxiliary relays and devices shall be of types, proven for the
application; satisfying requirements specified elsewhere and shall be subject to
Purchaser's approval. Numerical Relays shall have appropriate setting ranges, accuracy,
resetting ratio, transient overreach and other characteristics to provide required
sensitivity to the satisfaction of the Owner. All numerical relays shall be compatible
with IEC 61850.
c. All protective relays shall be in draw out or plug-in type / modular cases with proper
testing facilities. Necessary test plugs / test handles shall be supplied loose and shall be
included in supplier s scope of supply.
d. All AC operated relays shall be suitable for operation at 50 Hz. AC voltage operated
relays shall be suitable for 110 Volts VT secondary and current operated relays for 1
amp CT secondary. All relays and timers shall be rated for control supply voltage as
mentioned elsewhere under parameters and shall be capable of satisfactory
continuous operation between 80-120% of the rated voltage. Voltage operated relays
shall have adequate thermal capacity for continuous operation.
e. Multifuction meters shall be provided for incomer of 33kV & 11kV Switchgear and shall
able to communicate with SCADA at MRSS. The accuracy class of CT and VT for MFM
shall be 0.2.
f. Provision shall be made for easy isolation of trip circuits of each relay for the purpose
of testing and maintenance.
g. All protective relays and alarm relays shall be provided with one extra isolated pair of
contacts wired to terminals exclusively for future use.
h. The relay shall be designed to perform satisfactorily under highly noisy electrical
environment. Sufficient degree of high frequency disturbance immunity and impulse
voltage withstand capacity shall be built into electronic designs as stipulated in relevant
standards.
i. All protections shall be furnished complete with necessary auxiliary, supervisory, lock
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
11
out relays. Suitably separate sets of single phase auxiliary C.T with multiple taps shall
be provided with relay whenever required.
j. Visual and audible alarm annunciation shall be initiated in the event of operation of
protective/supervisory relay.
k. D.C supply shall be supervised by DC supervision relays.
l. Trip circuit shall be supervised by Trip circuit supervision.
m. Tripping shall be done through high speed lock out relays.
n. All meters/ instrument shall be flush mounted on front panel, at least 96 mm2 size with
90 degree linear scales and accuracy class of 2.0.
o. Interposing relays for ON/OFF command or any other command shall be as per system
requirement.
p. For alarm and Indication at SCADA placed at MRSS end necessary contacts shall be
provided at switchgear end.
q. Interposing relays for ON/OFF command or any other command shall be as per system
requirement.
For alarm and Indication at SCADA placed at MRSS end necessary contacts shall be
provided at switchgear end.
r. Metering and protection shall be as per below table
s. The relays shall have the following tools for fault diagnostics:
a. Fault record : The relay shall have the facility to store at least 100 last fault
records with information on cause of trip, date, time, trip values of
electrical parameters.
b. Event record : The relay shall have the facility to store at least 1000 time
stamped event records with 1ms resolution.
c. Disturbance records : The relay shall have capacity to store at least 50
disturbance record waveforms at 1 sec.
d. Event log, trip log and disturbance record should go in to history.
e. The relay settings shall be provided with adequate password protection.
PROTECTIONS
FOR INCOMERS
Instantaneous and Inverse time phase over current relay (50,51)Inverse time Earth
fault current relay (51N)
Directional inverse time phase over current relay (67)
Directional inverse time Earth fault current relay (67N)
Bus-bar differential relay (87B)- only for 33kV switchgear
Reverse blocking mechanics- only for 11kV switchgear
Cable differential relay (87C)- only for 33kV remote switchgears (Switchgears at
substation 2, 3 & 4)
Under voltage Protection (27)
Over voltage Protection (59)
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
12
Fault Disturbance Recorder (DR)
FOR OUTGOING FEEDERS EXCEPT TIE & TRANSFORMER FEEDERS
Instantaneous and Inverse time phase over current (50,51)
Inverse time Earth fault current (51N)
Bus-bar differential relay (87B) - only for 33kV switchgear
Reverse blocking mechanics- only for 11kV switchgear
Distance to fault locator (DFL)
FOR TIE FEEDERS
Instantaneous and Inverse time phase over current (50,51)
Inverse time Earth fault current (51N)
Bus-bar differential relay (87B) - only for 33kV switchgear
Reverse blocking mechanics- only for 11kV switchgear
Distance to fault locator (DFL)
FOR BUSCOUPLER
Instantaneous and Inverse time phase over current relay (50,51)
Instantaneous and Inverse time Earth fault current relay (51N)
Bus-bar differential relay (87B) - only for 33kV switchgear
Reverse blocking mechanics- only for 11kV switchgear
FOR PT/ LINE PT MODULES
Under voltage Protection (27)
Over voltage Protection (59)
TRANSFORMER FEEDERS
Instantaneous and Inverse time phase over current (50,51)
Inverse time Earth fault current (51N)
Instantaneous Earth fault current (50N)- for Transformer feeder (delta connected HV
winding)
Bus-bar differential relay (87B) - only for 33kV switchgear
Reverse blocking mechanics- only for 11kV switchgear
Distance to fault locator (DFL)
METERTING IN INCOMING & OUTGOING FEEDERS
Current in all the three phases (Metering at Switchgear end)
Voltage of all three phases
MWH
MW
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
13
MVARH
Frequency
Power Factor
Synchro. check
1.5 Tests
I. Type Test:
For each type & rating of 33kV & 11kV Switchgear, the Bidder shall submit the reports of all
the type tests as per relevant standards and carried out within [last five] years from the
date of bid opening for Owner s approval. These reports should be for the tests conducted
on the switchgear similar to those proposed to be supplied under this contract and the
test(s) should have been conducted at an independent laboratory.
In case the Bidder is not able to submit report of the type test(s) conducted within
last five years from the date of bid opening, or in case the type test report(s) are not
found to be meeting the specification requirements, the Bidder shall conduct all such
tests under this contract free of cost to the Owner and submit the reports for
approval.
II. Routine Test
All equipment shall be completely assembled, wired, adjusted and routine tested as per
relevant IS / IEC Standards at manufacturer's works in the presence of consultant
/purchaser or his representative. However the following minimum routine tests shall be
conduct.
Power-frequency voltage tests on the main circuit
Dielectric tests on auxiliary and control circuits
Measurement of the resistance of the main circuit
Partial discharge measurement
Mechanical operation tests
Heat Run test
Pressure tests of gas-filled compartments
Tests of auxiliary electrical, pneumatic and hydraulic devices
Verification of correct wiring
III. Test Witness
[The tests shall be carried out in presence of the Owner’s representative, for which a
minimum 7 days notice shall be given by the Bidder. The Bidder shall obtain the Owner’s
approval for the type test procedure before conducting the type test. The test procedure
shall clearly specify the test set-up, instruments to be used, procedure, acceptance
norms, recording of different parameters, interval of recording, precautions to be taken
etc. for the type test(s) to be carried out.]
IV. Test Certificates:
Certified copies of all tests carried out at works and at site shall be furnished in requisite
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
14
no. of copies for approval of the Owner. The equipment shall be dispatched from works
only after receipt of Owner's written approval of shop test reports.
1.6 Drawing & Documents
Drawings, data & manuals for the motors shall be submitted as indicated below.
a. [General Arrangement drawings and cross-section showing constructional features &
cable entry with bottom view with opening]
b. Bill of Materials.
c. Technical Data sheet and Catalogue.
d. Foundation drawing details with bottom view of switchgear.
e. Descriptive write-ups and literature for the main equipment offered including relays,
meters, etc.
f. Control Schematics & Wiring diagram.
g. Inspection and Test Plan (ITP).
h. Suggestive list of protective relays.
i. Transport/shipping dimensions and weights].
1.7 Ratings & Requirements
33kV & 11kV Switchgear shall comply with the particulars indicated in the following tables.
Table 2.0
S. No. DESCRIPTION UNIT DATA
1.0 General
1.1 Name of Manufacturer [By Bidder]
1.2 Place & Country of manufacture [By Bidder]
2.0 Switchgear Details
2.1 Rated voltage(Nom/Max), phases &
frequency
11 kV/12 kV, 3 Phase, 3 wire, 50
Hz.
33kV / 36kV, 3 Phase, 3 wire, 50
Hz.
2.2 System neutral earthing Solidly Earthed
2.3 Voltage & frequency variation % +/-10%, -5%to +3% Hz.
2.4 Rated frequency Hz 50Hz
1.4
2.4
Insulation Level
One minute power frequency
Voltage
28kV for 11kV Switchgear & 70kV
for 33kV Switchgear
75kV for 11kV Switchgear & 170kV
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
15
S. No. DESCRIPTION UNIT DATA
Impulse withstand Voltage for 33kV Switchgear
2.5 Continuous current rating of busbars
under site reference ambient temp.
[As per Project requirement]
2.6 Reference ambient temperature 45C
2.7 Maximum temperature of bus bars
and droppers/connectors under site
conditions specified
Continuous current without
exceeding the temperature of 90
°C. For silver plated joints
maximum temperature shall be
limited to 105 °C.
2.8 Short circuit current withstand for
busbars and droppers
a Short time kA (rms) 26.2 kA for 1 Sec at 33kV and 18.3
kA for 1 sec at 11kV
b Dynamic Rating kA (peak) 65.5 kA for 33kV & 46kA for 11kV
c Intern Arc AFLR Ka 31.5 kA for 1Sec at 33KV
25 Ka for 1Seca at 11KV
2.9 Whether busbars have been insulated Yes Required
2.10 Type of insulation [By Bidder]
2.11 Material of bus bar supports [By Bidder]
2.12 Switchgear designation [As per project specific]
2.13 Bus bar material Al
2.14 Fully draw out (FD)/ Fixed (F) FD / Single front
2.15 Entry –Top (T)/Bottom (B) Bottom for cables.
2.16 Degree of protection IP-42 and for LV chamber shall be
IP-52.
2.17 Color finish shade Interior
Exterior
Siemens Grey
RAL 7032
2.18 Earthing bus Material Aluminum
2.19 Minimum clearances in air of live parts mm As per standard
3.0 Circuit breakers
3.1 Maker s name
3.2 Voltage, frequency & no. of phases ,
poles
33kV,50hz,3 phase,3 pole &
11kV,50hz,3 phase,3 pole
3.3 Rated operating duty O-0.3sec-CO- 3min -CO
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
16
S. No. DESCRIPTION UNIT DATA
3.4 Circuit breakers type VCB
3.5 Short circuit withstand current for 1
sec. Duration
kA 26.2 at 33kV ; 18.3 at 11kV
3.6 Rated making current kAp 100
3.7 Rated current at site reference
ambient temp
A
[By bidder]
3.8 Type of operating mechanism Spring charged motor and manual
3.9 Minimum no. of auxiliary
Contacts for purchaser s use
6 NO, 6 NC
3.10 Control voltage
For Spring charging motor V AC/DC 230V AC
3.11 Closing Coil
a Voltage V 110 V
b Permissible Voltage Variation % 85% to 110%
c Closing Current at rated Voltage A Within Limit
3.12 Opening Coil
a Voltage V 110 V
b Permissible Voltage Variation % 85% to 110%
c Closing Current at rated Voltage A Within Limit
3.13 Operating time
Opening time ms <65
Breaking time ms <15
Total tripping time ms <80 (total break time)
Total Closing time ms <80 ms
3.14 Number of breaks per pole One
4.0 Contactor
Voltage class kV 36; 12
Short time Rating [By bidder]
Duty AC3
5.0 Fuse
Voltage class kV 33; 11
Rupturing capacity kAp 100
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
17
S. No. DESCRIPTION UNIT DATA
6.0 Current Transformer
a Make [By bidder]
b Type Resin Cast
c Rated frequency 50Hz
d Class of Insulation [Class E]
e Basic Insulation level kV For 33kV- 36/70/170
For 11kV- 12/28/75
6.1 CT for differential protection
Class PS class
Secondary resistance at 75 0 C [By bidder]
Knee Point Voltage [By bidder]
Excitation Current <30mA
6.2 CT for Metering
Class 0.2 for incomers, 1 for outgoings
Secondary resistance at 75 0 C [By Bidder]
6.3 CT for Protection
Class [5P20 ]
7.0 Voltage Transformer
a Make [By Bidder]
b Type Resin Cast
c Rated frequency 50Hz
d Class of Insulation [Class E]
e Voltage ration [By Bidder]
8.0 Meters
a Make [By Bidder]
b Type [By Bidder]
8.1 Voltmeter
a Make [By Bidder]
b Type [By Bidder]
c Applicable standards As specified in the specification.
d Accuracy class Class 0.2 for line, Class 0.5 for bus
8.2 Ammeter
a Make [By Bidder]
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
18
S. No. DESCRIPTION UNIT DATA
b Type [By Bidder]
c Applicable standards As specified in the specification.
d Accuracy class Class 0.2 for incomers, Class 1.0 for
outgoing
9.0 Indicating lamps
a Make [By Bidder]
b Type [By Bidder]
c Voltage V As specified in the specification.
d Wattage of lamp W [By Bidder]
10.0 Push buttons
a Make
b Type As specified in the specification.
c Contact rating A [By Bidder]
11.0 Space heater
a Make
b Type As specified in the specification.
c Rated voltage V As specified in the specification.
d Power rating W [By Bidder]
12.0 Wiring and terminal blocks
a Voltage grade 1.1 kV
b Insulation [By Bidder]
c Minimum size of conductor for:
Power wiring Sq.mm 2.5 for CT & PT for internal panel
wiring only and 4 for external
wiring
Control wiring Sq.mm 1.5 (for internal panel wiring only)
f Type of terminal blocks:
g I) For Withdraw able Type Sliding type
h II) For Fixed Type Stud & nut type
i Minimum current rating of terminal
blocks
A 10
14.0 Relays
a Make
b Model Number
Technical Specification for 33 kV & 11 kV
INDOOR SWITCHGEAR UNITS
ABD, Ranchi Smart City
19
S. No. DESCRIPTION UNIT DATA
c Parameter Catalogue shall be furnished by the
bidder.
TECHNICAL SPECIFICATION
FOR POWER TRANSFORMERS
Contents
1 POWER TRANSFORMER .............................................................................................................. 3
1.1 General ..................................................................................................................................................... 3
1.2 Codes and Standards ................................................................................................................................. 3
1.5 Specific Requirements ............................................................................................................................... 6
i. No Load Losses : 8.3 KW (max) ................................................................................................................... 18
ii. Load Losses at 750
C : 65 KW (max) .............................................................................................................. 19
1.1 General ..................................................................................................................................................... 3
1.2 Codes and Standards ................................................................................................................................. 3
1.6 Drawings/ Data and Manuals .................................................................................................................. 13
1.7 Ratings and Requirements ...................................................................................................................... 14
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
1.0 LV TRANSFORMER (DRY TYPE/OIL TYPE)
1.1 General
This specification is intended to cover [design, Engineering, manufacture, assembly,
testing at manufacturer's works, supply in properly packed condition for transport to
site, Erection, site testing and commissioning] of LV Transformers (Dry type/Oil type)
The system shall be complete in all respect including all accessories required for efficient
and trouble-free operation of Ranchi Smart City, Jharkhand
1.2 Codes and Standards
All equipment and materials shall be designed, manufactured and tested in accordance
with the latest applicable Indian Standards (IS) / IEC as given below except where
modified and/or supplemented by this specification.
Table 1.0
CODE NAME OF STANDARD
IS:334 Dimensions for porcelain Transformer bushing
IS:335 New insulating oil for transformers and switchgears
IS:1271 Classification of insulating materials for Electrical
Machinery and apparatus in relation to their stability in
service.
IS 2026 Specification for power Transformer (all parts)
IS:2071 Method of high voltage testing
IS:2099 High voltage porcelain bushings
IS:2147 Degree of protection.
IS:2705 Current transformers
IS:3202 Code of practice for Climate proofing of electrical
equipment
IS:3637 Gas operated relays
IS:3639 Fittings and accessories for power Transformers
IS:5561 Electric Power connectors
IS:6600 Guide for loading of oil immersed transformers
IS: 11171 Dry type transformers
IS:10028 Code of practice for selection, Installation and
maintenance of transformers Part I, II and III
CBIP Manual on transformers
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
CODE NAME OF STANDARD
IEC60076 Power Transformer
IEC 60214 Tappings
IEC 60726 Dry-type power transformers
IEEE C57.12.01 General Requirements for Dry-Type Distribution and Power
Transformers Including Those with Solid Cast and / or
Resin-Encapsulated Windings
ANSI C57.12.51 Requirements for Ventilated Dry-Type Power
Transformers, 501 KVA and Larger, Three-Phase with High-
Voltage 601 to 34 500 Volts, Low Voltage 208Y/120 to 4160
Volts
ANSI C57.12.55 Dry-Type Transformers in Unit Installations, Including Unit
Substations –Conformance Standard
ANSI/IEEE
C57.98
Impulse Tests, Guide for Transformer (Appendix to
ANSI/IEEE C57.12.90)
ANSI/NFPA 70 National Electrical Code
IEEE C57.12.91 Test Code for Dry-Type Distribution and Power
Transformers
IEEE C57.94 Recommended Practice for Installation, Application,
Operation and Maintenance of Dry-Type General Purpose
Distribution and Power Transformers
IEEE C57.96 Guide for Loading Dry-Type Distribution and Power
Transformers
NEMA ST 20 Dry Type Transformers for General Applications
CEA CEA Regulations
Equipment and material conforming to any other standard, which ensures equal or
better quality, may be accepted. In such case, copies of the English version of the
standard adopted shall be submitted along with the bid.
The electrical installation shall meet the requirements of Indian Electricity Rules as
amended up to date and relevant IS Code of Practice. In addition, other rules and
regulations applicable to the work shall be followed.
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
1.3 Design Criteria
a) The transformers shall be dry type (AN) for indoor location and shall be oil type
(ONAN) for outdoor location.
b) The oil type transformer shall be installed in hot, humid and tropical atmosphere
with ambient temperature equal to 45oC. All equipment, accessories and wiring
shall be provided with tropical finish to prevent fungus growth.
c) The transformer shall be capable of continuous operation at specified rating
under the following condition:
i) Voltage variation - ±10%
ii) Frequency variation - [+3% ,-5%]
iii) Combined voltage and
frequency variation (absolute sum) - [10%]
d) The transformer shall be capable of withstanding the short circuit stresses due to
a terminal fault on one winding with full voltage maintained on the other winding
for minimum period of two (2) seconds.
e) The noise level shall be limited to the value specified by NEMA Standard
Publication No. TR-1-1993 when measured in accordance with conditions outlines
in ANSI/IEEE C57.12.90-1999/IS13964/CBIP publication.
f) The design shall be such as not to cause any undesirable interference with radio
or communication circuits.
g) Transformers shall accept without injurious heating, combined voltage and
frequency variation which produce an over fluxing condition of 120% for one (1)
minute.
h) Each transformer shall be sized based on actual load with 10% margin and
considering voltage regulation factor. It shall be sized by considering 100% load
connected on the bus considering other transformer outage. An appropriate load
factor of 0.9 for continuous and 0.2 for intermittent shall be considered.
i) The impedance of the transformers shall be chosen such that the fault level on the
LV switchgear does not exceed 50kA including the motor contributions and also
voltage dip while starting the motor does not exceed 15% at motor terminal.
1.4 Specific Requirements of Transformers
1.4.1 Enclosure (for dry type)
a) The encapsulated cast resin transformer shall be housed in naturally ventilated floor
mounted cold rolled sheet steel cubicle with louvers backed by fine brass wire
mesh. The enclosure shall be of bolted type fabrication and degree of protection
shall be at least IP32. The minimum sheet steel thickness shall be 2 mm.
b) Enclosure shall be provided with lifting lugs and grounding terminals at both ends.
Further, the enclosure door shall have pad locking provision.
c) The enclosure door shall be interlocked with service transformer incoming breaker
such that.
The door can be opened only when the service transformer HV side circuit
breaker is in Test/Isolated position.
11 kV side circuit breaker can be closed only when the doors are closed.
d) Necessary illumination with controls shall be provided in the enclosure.
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
e) Thermostatically controlled space heater inside the enclosure of suitable rating shall
be provided, if necessary.
1.4.2 Tank (for oil type)
a) For LV transformers, the tank shall be of conventional type.
b) Tank shall be made from good commercial grade low carbon steel and shall be of
welded construction.
c) Tank shall be designed to permit lifting, by crane or jacks of the complete
transformer assembly filled with oil. Suitable lugs and bosses shall be provided for
this purpose.
d) Tank together with radiators, coolers, conservator, bushings vessel and other
fittings, shall be designed to withstand full vacuum without permanent distortion.
e) The transformer top shall be provided with a detachable tank cover with a bolted
flanged gasket joint. Lifting lugs shall be provided for removing the cover. The
surface of the cover shall be suitably sloped so that it does not retain rain water.
f) The material used for gaskets shall be cork-neoprene or approved equivalent.
Gasketed joints for tank and manhole covers, bushings and other bolted
attachments shall be so designed that the gasket will not be exposed to the
weather. Spare gaskets shall be provided for all openings as shipping gaskets will
not be reused.
g) Tank shall be provided with all necessary valves.
h) Tank shall be provided with a pressure release device which shall operate at a
pressure below the test pressure for the tank and radiators. This device shall be of
sufficient size for rapid release of any pressure that may be generated in the tank
and which may result in damage to the equipment. The device shall be rain proof
after blowing and shall be provided with a device visible from ground to indicate
operation. An equaliser pipe connecting the pressure relief device to the
conservator shall be supplied. This device shall be provided for all transformers.
Pressure relief device shall be equipped with remote monitoring/alarm contacts
1.4.3 Core
a) The transformers shall be three phase core type. The core shall be built up with
high grade, non-ageing, low loss, high permeability grain oriented cold rolled silicon
steel laminations especially suitable for core material. Laminations shall be annealed
in a non-oxidizing atmosphere to relieve stresses and restore the original magnetic
properties of CRGO sheets after the cutting and punching operations.
b) CRGO sheets shall be coated with insulation varnish. Insulation shall be able to
withstand the curing temperature and shall reduce eddy current to minimum. The
core shall be protected from corrosion with a rust-resistant coating.
c) The core clamping brackets shall be designed to provide an even distribution of
clamping forces to the core, yokes and legs and shall be rigidly braced to reduce
sound levels and losses.
1.4.4 Winding
a) The coils shall be manufactured from electrolytic copper conductor with sufficient
number of radial supports and fully insulated for rated voltage.
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
b) Insulating material shall be of proven design, Coils shall be so insulated that impulse
and power frequency voltage stresses are minimum. The insulating material for dry
type transformers shall be glass fibre reinforced conforming to class `F’. Coils shall
be so insulated that impulse and power frequency voltage stresses are minimum
and are suitable to withstand even the severest of temperature fluctuation.
c) Coil assembly shall be suitably supported between adjacent sections by insulating
spacers and barriers. The windings shall be arranged to ensure a free circulation of
the air and to reduce the hot spots in the winding.
d) All leads from the windings to the terminal board and bushings shall be rigidly
supported to prevent injury from vibration or short circuit stresses. Guide tube shall
be used where practicable.
e) The core and coil assembly shall be securely fixed in position so that no shifting or
deformation occurs during movement of transformer, under short circuit stresses,
switching or other transients.
f) All coils rated 1200V or higher shall be subjected to partial discharge tests to ensure
a properly cured and void free casting.
1.4.5 Encapsulation (for dry type)
a) HV and LV coils shall be separately cast under vacuum in fibre glass reinforced epoxy
resin compound. The insulation shall be fire resistant, non-inflammable, non-
hygroscopic and resistant to temperature fluctuations.
b) The epoxy shall contain filler material providing characteristics superior to unfilled
epoxy including higher temperature rating, better heat conductivity, better arc
resistance and adhesion to the conductor, plus a coefficient of expansion closer to
that of the conductor material. The epoxy resin shall be self extinguishing.
c) Encapsulated winding shall be free of internal voids, surface irregularities, etc. No
surface finishing of encapsulated winding shall be undertaken after the process of
encapsulation.
1.4.6 Insulating Oil (for oil type)
a) The transformer shall be filled with mineral insulating oil suitably inhibited to
prevent sludging.
b) The quality of oil to be supplied for the transformer shall conform to the
parameter specified in IS: 335 with latest amendments. No inhibitors shall be used
in oil. Prior to filling oil shall be tested as per IS: 335 for tan delta, specific
resistivity, breakdown voltage, moisture content etc.
c) Transformer shall be dispatched oil filled. 10% excess oil for topping up shall be
supplied in non-returnable container suitable for outdoor storage.
d) Oil preservation shall be by means of conservator tank complete with silica gel
breather and oil seal.
e) Oil preservation shall be by means of bellows/ diaphragm sealed conservator tank
with silica gel breather to avoid direct connection between atmosphere and
transformer oil. It shall be complete with level gauges, pipes , drain valve etc. The
level gauges shall be so placed that same can be readable standing from ground.
f) Necessary device shall be kept to provide annunciation in the event of rupturing
of bellow.
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
1.4.7 Tappings (OCTC)
a) Off-circuit taps as specified shall be provided on the high voltage winding.
b) The transformer shall be capable of operation at its rated KVA on any tap provided
the voltage does not vary by more than ±10% of the rated voltage corresponding
to the tap.
c) The winding including the tapping arrangement shall be designed to maintain
electromagnetic balance between HV and LV windings at all voltage ratios.
d) A warning plate indicating that switch shall be operated only when the
transformer is de-energized shall be provided.
e) Off circuit tap changer switch where provided shall be 3 phase, hand operated, by
an external handle with position markings and pad locking facility and mechanical
stops to prevent over cranking beyond extreme positions.
f) Arrangement shall be such that switch can be operated at standing height from
ground level.
g) The operating handle can be padlocked at any tap position. The design shall be
such that the lock cannot be inserted unless the contacts are correctly engaged.
The mechanism shall be provided with a mechanical tap position indicator with
pad locking facility.
1.4.8 Fittings and Accessories:
The following fittings and accessories shall be provided :
a) Earthing pads: Two earthing pads of copper or other non-corrodible material shall
be welded at the bottom corners of the transformer tank and supplied with clamp
type terminals suitable for the purchaser’s earthing conductors. Suitable earthing
terminals on cable boxes shall also be provided.
b) Terminal marking and rating plates shall be as per the specified standard.
c) In case of oil type, the conservator shall be of sufficient volume to maintain the oil
seal from the minimum ambient temperature of – 5oC up to an oil temperature of
100oC, with oil level varying within the minimum and maximum visible levels with
necessary accessories.
d) In case of oil filled type, Valves shall be supplied on the transformer tank and
radiators.
e) Pressure relief device: Pressure relief device shall be provided for transformers
rated 2 MVA and above which shall be of sufficient size for rapid release of any
pressure that may be generated within the tank and which may result in damage of
the equipment
f) Gas and Oil Actuated Relay (Magnetic Reed Type Gas & Oil Relay):
A double float type magnetic reed type gas and oil relay as per applicable standard
shall be provided for all oil filled transformers. All gas evolved in the transformer
shall collect in this relay. The relay shall be provided with a test cock suitable for a
flexible pipe connection for checking its operation. The device shall be provided with
two electrically independent ungrounded contacts, one for alarm on gas
accumulation and the other for tripping on sudden rise of pressure.
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
These contacts shall be wired up to the transformer marshalling box. The relay shall
be provided with shut off valves on the conservator side as well as the tank side.
g) Temperature Indicators
i Oil temperature indicator (OTI)
All oil type transformers shall be provided with a 150 mm dial type
thermometer for top oil temperature indication. The thermometer shall have
adjustable, electrically independent ungrounded alarm and trip contacts,
maximum reading pointer and resetting device. The contacts shall be rated
minimum 0.5A making and 0.2A breaking at 110V DC.
ii Winding Temperature Indicator (WTI):
A device for measuring the hot spot temperature of the winding shall be
provided. The accuracy class of winding temperature indicator shall be ± 20oC or
better.
iii Oil Level Indicator:
A magnetic type oil level indicator shall be provided to indicate oil level in the
tank.
iv RTD/transducers for remote annunciation:
In addition to the above mentioned indicators, the Oil and winding temperature
measurement, RTDs / transducers shall be provided for remote indication in the
DCS. RTDs shall be duplex platinum type with nominal resistance of 100 ohms at
zero degree centigrade.
h) Bushing Current Transformers for stand by earth fault protection shall be provided
in the neutral bushing and lead shall be brought to Marshalling box.
i) Radiator (oil filled type): Tank mounted radiators banks shall have bolted flanged
connections and pipe extensions to permit withdrawal of transformer tank without
disturbing the radiators. Flexible joints shall be provided in the interconnecting
pipes (unless otherwise approved) to facilitate erection and dismantling and reduce
transfer of vibrations from tank to radiator. The interconnecting pipes shall be
provided with drain plug and air release vents.
j) Conservator (For oil filled type): The transformers rated below 7.5MVA shall be
provided with conventional single compartment conservator with dry air filling the
space above the oil.
1.4.9 Bushings
a) The bushing shall conform to the requirements of IS:2099 and IS:3347.
b) All transformer bushings shall be of porcelain (for oil filled)/ epoxy (for dry type).
c) The neutral terminal of 433V winding shall be brought out on a bushing along with
the 433V phase terminal to form a 4 wire system for the 433V.
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
d) Neutral CTs shall be located in the lead coming out of the winding and location of
these CTs shall not be inside the tank.
e) The neutral terminal of secondary shall be brought out through an outdoor. Further
this neutral terminal shall be connected by a GS of size 50 mm x 6mm, which shall
be brought down upto 100 mm above ground. The GS shall be insulated and
supported from the tank body.
1.4.10 Terminal arrangement
a) Cable boxes
i. Wherever cable connections are specified, suitable cable boxes shall be
provided and shall be air insulated.
ii. Cable boxes shall have drilled gland plate of adequate size to receive cables
and to allow easy termination.
iii. Removable drilled gland plates shall be provided in the cable boxes.
iv. The additional supports for the cable boxes shall be galvanised iron.
v. The contractor shall provide earthing terminals on the cable box, to suit
50mmx6 mm GS flat.
1.4.11 Marshalling box
a) A sheet steel weather, vermin and dust proof marshalling box shall be furnished.
The sheet steel used shall be at least 2.0 mm (CRCA) thick. The box shall be free
standing floor mounted/tank mounted type and have a sloping roof. The degree of
protection shall be IP-55 in accordance with IS:2147.
b) The marshalling box shall have a glazed door of suitable size for convenience of
temperature indicators reading.
c) All incoming cables shall enter the marshalling box from the bottom.
1.4.12 Wiring
a) All control, alarm and indication devices provided with the transformer shall be
wired up to the terminal blocks.
b) Wiring shall be done with 650V PVC wires in conduit or PVC armored cable.
Minimum wire size shall be 1.5 sq.mm stranded copper. Not more than two wires
shall be connected to a terminal. 20% spare terminals shall be provided.
c) Multi-way terminal block complete with mounting channel, binding screws and
washers for wire connections and marking strip for circuit identification shall be
provided for terminating the panel wiring. Terminals shall be stud type, suitable for
terminating 2 nos. 2.5 mm2 stranded copper conductor and provided with acrylic
insulating cover.
d) All devices and terminal blocks shall be identified by symbols corresponding to
those used in applicable schematic or wiring diagram. Each wire shall be identified,
at both ends, with interlocking type permanent markers bearing wire numbers as
per Bidder's Wiring Diagrams. AC / DC wiring shall have separate colour-coding.
e) Wire termination shall be made with crimping type connectors with insulating
sleeves. Wires shall not be spliced between terminals.
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
1.4.13 Painting
a) All steel surfaces shall be thoroughly cleaned by sand blasting and / or by chemical
agents, as required to produce a smooth surface free of scales, grease and rust.
b) The external surfaces, after cleaning, shall be given a coat of high quality red oxide
or yellow chromate primer followed by filler coats.
c) The transformer finished with two coats of epoxy based powder coated paint. The
paints shall be carefully selected to withstand tropical heat, rain etc. The paint shall
not scale off or crinkle or be removed by abrasion due to normal handling.
d) Painting shade shall be subject to owner’s approval.
e) Sufficient quantity of touch-up paint shall be furnished for application at site.
1.4.14 Name Plate
Nameplates of approved design shall be furnished at each cubicle (one no. each at front
as well as at backside of cubicle) and at each instruments & device mounted on or inside
the cubicle. The material shall be lamicoid or approved equal, 3 mm thick with white
letter on black background. Self-tapping screws shall hold the nameplate. Nameplate
size shall be minimum 20 x 75mm for instrument/device and 40 x 150mm for panels.
Caution notice on suitable metal plate shall be affixed at the back of terminal Box.
1.5 Tests
1.5.1 Type Tests
For each type & rating of LV Transformers, the Bidder shall submit for Owner’s approval
the reports of all the type tests as per relevant standards and carried out within last five
years from the date of bid opening. These reports should be for the tests conducted on
the equipment similar to those proposed to be supplied under this contract and the
test(s) should have been conducted at an independent laboratory.
In case the Bidder is not able to submit report of the type test(s) conducted within last
five years from the date of bid opening, or in case the type test report(s) are not found
to be meeting the specification requirements, the Bidder shall conduct all such tests
under this contract free of cost to the Owner and submit the reports for approval.
The following shall constitute the type tests:
a) Temperature rise test
b) Dielectric test
1.5.2 Routine Tests
All equipment shall be completely assembled, wired, adjusted and routine tested as per
relevant IS / IEC Standards at manufacturer's works in the presence of consultant
/purchaser or his representative.
The following tests shall be performed on each transformer as a minimum:
a) After assembly, each core shall be pressure tested for one minute at 2KV (r.m.s.)
A.C. between all bolts, side plates, structural steel works and the core.
b) The wiring for auxiliary power and control circuitry shall be subjected to withstand
one minute power frequency test with 2.0KV (r.m.s.) to earth
c) Measurement of winding resistance
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
d) Measurement of voltage ratio and check of phase displacement
e) Measurement of short circuit impedance and load loss
f) Measurement of no load loss and current
g) Dielectric routine tests
h) Excitation loss and current measurements shall be made at 90%, 100% and 110% of
the rated voltage as routine test.
i) Partial discharge test
j) Tan delta test
1.5.3 Test Witness
[The tests shall be carried out in presence of the Owner’s representative, for which a
minimum 7 days notice shall be given by the Bidder. The Bidder shall obtain the Owner’s
approval for the type test procedure before conducting the type test. The test
procedure shall clearly specify the test set-up, instruments to be used, procedure,
acceptance norms, recording of different parameters, interval of recording, precautions
to be taken etc. for the type test(s) to be carried out.]
1.5.4 Test Certificates
a) Certified copies of all tests carried out at works and at site shall be furnished in
requisite no. of copies for approval of the Owner.
b) The equipment shall be dispatched from works only after receipt of Owner's
written approval of shop test reports.
1.6 Drawings/ Data and Manuals
Drawings, data, and manuals for the transformers shall be submitted as indicated
below:
a) [General Arrangement Drawing
b) Dimensioned general arrangement drawing showing enclosure, core coil assembly,
terminal arrangement, marshalling box and various fittings.
c) Transport/shipping dimensions with weights, wheel base detail etc.
d) Foundation plan & loading.
e) Bus duct/cable termination arrangement.
f) Control schematics and wiring diagrams.
g) Test reports and QAP
h) Any other relevant drawing or data necessary for satisfactory installation, operation
and maintenance.
i) Instruction manuals on Transformer and its various fittings The manual shall clearly
indicate method of installation, checkups and tests to be carried out before
commissioning of the equipment.]
Note: The drawings, data and manuals listed are minimum requirement only. The Bidder
shall ensure that all other necessary write-ups, curves and information required to
fully describe the equipment offered are submitted.
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
1.7 Ratings and Requirements
Table 2.0
11/0.433 kV DRY TYPE TRANSFORMER
Dry Type Oil Type
1. Application
DISTRIBUTION
DISTRIBUTION
2. Location Indoor Outdoor
3. Type Dry Type: epoxy cast resin
transformer
Oil type transformer
4. Reference standard IS 11171 IS 2026
5. Rated power (indicative)
500 kVA
[As per project
requirement]
6. Rated winding voltage ratio
(line to line)
11.0/0.433 kV 11.0/0.433 kV
7. Number of phases 3 3
8. Winding 2 2
9. Rated frequency 50 Hz 50 Hz
10. Type of cooling AN ONAN
11. Insulation Class Class F or Better Class F or Better
12. Temperature rise Over
ambient temperature of
45oC
a. For Winding by resistance
method
90oC or lower as
permissible for class of
insulation offered
60oC
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
b. For Oil by Thermometer
method
Not Applicable 55 o
C
13. Insulation level
( LI/AC)
a. HV- (LI/AC) 70 KVp/28 kVrms 70 KVp/28 kVrms
b. LV- (LI/AC) - KVp/3KVrms -KVp/3KVrms
14. Vector group Dyn11 Dyn11
15. Short-circuit impedance on
principal tap
4 % [As per project
requirement]
16. Parallel operation of
transformer
Momentarily Momentarily
17. Type of taps provided OCTC, full capacity OCTC, full capacity
18. Taps provided on H.V. winding H.V. winding
19. Range of taps
+/- 5 % in steps of
2.5%
+/- 5 % in steps of
2.5%
20. Method of Tap charge
control-
a. Manual local Yes Yes
b. Electrical local No No
c. Electrical remote No No
d. Automatic No No
21. System earthing
a. H.V. Non-effectively earthed Non-effectively earthed
b. L.V. Effectively earthed Effectively earthed
22. Terminal arrangement
a. H.V. 11.0kV(UE) Cable/ Cable [As per project
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
requirement]
b. L.V. Cable Cable
23. Neutral for earthing GS flat connector GS flat connector
24. Transformer bushing HV LV LV - N
Same as Dry type
transformer
25. Voltage class KV(r.m.s.) 12 1.1 1.1
26. Creepage distance mm 25mm/kV 25mm/kV
27. Min. Ph-Ph/ Ph-E clearance
mm
As per Standard
As per standard
28. System fault Level
a. HV Side 18.3 KA (r.m.s.) 18.3 KA (r.m.s.)
b. LV Side 50KA (r.m.s.) 50KA (r.m.s.)
29. Max. Noise level As per NEMA std. TR-1 As per NEMA std. TR-1
30. Auxiliary supply 415 V, 3 ph, 3 wire AC, 50
Hz
110V +10%, -15% 2 wire
DC(if required)
415 V, 3 ph 3 wire AC, 50
Hz
110V +10%, -15% 2 wire
DC(if required)
31. LV neutral side current
transformer for standby
earth fault protection
Yes [As per project
requirement]
32. Guaranteed no load loss
(kW)
[By Bidder] [By Bidder]
33. Guaranteed load loss
(kW)
[By Bidder] [By Bidder]
34. Efficiency
a At full load [By Bidder] [By Bidder]
b At 75% load [By Bidder] [By Bidder]
Tender Specification for LV TRANSFORMERS
ABD, Ranchi Smart City
c At 50% load [By Bidder] [By Bidder]
TECHNICAL SPECIFICATION
FOR RING MAIN UNIT
Contents
1. RING MAIN UNITS ............................................................................................................................. 4
1.1 General ..................................................................................................................................................... 4
1.2 Applicable Codes and Standards ............................................................................................................... 4
1.5 SF6 Gas .................................................................................................................................................... 11
1.10 Current Transformers .............................................................................................................................. 15
1.11 Bushings and cable terminations ............................................................................................................. 15
1.16 Self-Heal Grid System .............................................................................................................................. 18
1.17 SCADA Features ...................................................................................................................................... 18
1.18 General ................................................................................................................................................... 19
1.19 Routine Test ............................................................................................................................................ 20
1.20 Type Test ................................................................................................................................................. 21
1.21 Drawings and Data .................................................................................................................................. 22
1.22 Technical Data Sheet ............................................................................................................................... 23
Technical Specification for RING MAIN UNIT
ABD, Ranchi Smart City
1. RING MAIN UNITS
1.1 General
This specification is intended to cover the [design, Engineering, manufacture, assembly,
testing at manufacturer's works, supply in properly packed condition for transport to
site, Erection, site testing and commissioning] of 33kV & 11kV RING MAIN UNITS.
The system shall be complete in all respect including all accessories required for efficient
and trouble-free operation of Ranchi Smart City, Jharkhand
All the ratings, indications, protections, annunciation & accessories indicated in
SLD/Datasheet/specifications are minimum requirements & Contractor to provide any
additional accessories / components / ratings to suit the actual requirements & for
successful commissioning of 33kV & 11 kV RMU along with its integration with SCADA
system located in MRSS through FRTU, which shall be part of RMU & placed in the same
enclosure.
Equipment Manufacturer s person shall supervise- equipment commissioning activities
to be carried out by Contractor s personnel. The same shall be considered in Contractor s
offer.
All the requirements of this specification are to be considered in conjunction with other
sections of the specifications.
1.2 Applicable Codes and Standards
1 The design, material, construction, manufacture, inspection and testing of Switchgear
shall comply with all currently applicable statutes, regulations and safety codes in the
locality where the Equipment will be installed. The Equipment shall also conform to the
latest applicable standards.
2 The Equipment shall conform to the latest standards specified. In case of conflict
between the standards and this specification, this specification shall govern.
Technical Specification for RING MAIN UNIT
ABD, Ranchi Smart City
HV switchgear and control gear-AC Metal
Enclosed switchgear and control gear
HV switchgear and control gear-AC Metal
Enclosed switchgear and control gear
Circuit Breakers
IEC 62271-1
IEC 62271-200
IS / IEC 62271-100
Disconnectors & Earthing Switches
Metal Enclosed switchgear
IEC 62271-102
IS : 3427 / BSEN:60298 / IEC:298 / IEC 265
Current Transformers IS : 2705 / BS : 7626 / IEC:60044-1
Voltage Transformers IS : 3156 / BS : 7625 / IEC: 186 / IEC:60044-2
Arrangement for Switchgear Bus bars, Main
Connections and Auxiliary wiring
IS : 5578, 11353
Busbar Support insulators IS: 2544 / BS : 3297 / IEC : 273
Degree of Protection IS : 13947 (Part 1) / IEC : 947-1 / IEC : 60529
Electrical Relays for Power system protection IS : 3231, 3842 / BS : 142 / IEC : 255
7.1 Type Test ....................................................................................................................... 14
7.2 Routine Test ................................................................................................................... 15
7.3 Drawings, Data and Manuals ......................................................................................... 15
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
POWER AND CONTROL CABLES
1.0 GENERAL
This specification is intended to cover the [design, engineering, manufacture, assembly, testing at manufacturer's works, supply in properly packed condition for transport to site, Erection, site testing and commissioning] of MV(33kV &11kV),three core XLPE insulated unarmoured cable having stranded Aluminium, copper wire screen and extruded PVC or PE over sheath complete with all accessories for efficient and trouble-free operation.
2.0 CODES AND STANDARDS
All equipment and materials shall be designed, manufactured and tested in accordance with the latest applicable Indian Standards (IS) / IEC as given below except where modified or supplemented by this specification.
S.N Standard Number Description
1 IS: 2982 Copper conductor in insulated cables and cords.
2 IS: 3961 Recommended current ratings for cables.
3 IS: 3975 Mild steel wires, strips and tapes for armouring cables
4 IS: 5609 Specification for low frequency wirers and cables with PVC insulation and PVC sheath
5 IS:5831 PVC insulation and sheath of electric cables
6 IS: 6380 Specification of elastomeric insulation of sheath of electric cables.
7 IS:7098(Part II) XLPE insulated PVC sheathed cables for working voltage from 3.3kV up to and including 33kV
8 IS: 8130 Conductors for insulated electric cables and flexible cords
9 IEC: 60 High voltage test techniques
10 IEC: 71 Insulation co-ordination
11 IEC: 60228 Conductors of insulated cables
12 IEC: 60229 Tests on cable over sheaths
13 IEC: 60230 Impulse tests on cables and their accessories
14 IEC: 60287 Calculation of the continuous current rating of the cables(100% load factor).
15 IEC: 60288 Nominal cross sectional area and composition of conductor of insulated cables.
16 IEC-331 Fire resisting characteristics of electric cables
17 IEC: 332-1 Test on electric cables under fire conditions.
18 IEEE: 383 Standard for type test for class IE electric cables, filled splices and connection for nuclear power generation
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
S.N Standard Number Description
station.
19 IEC: 60502 Extruded solid dielectric insulated power cables for rated voltages from 1kV upto 30kV.
20 IEC: 60 540 The methods for insulations and sheath of electric cables and cords(elastomeric and thermoplastic compounds)
21 IEC-754-I Test method for acid gas generatin
22 NEMA-WC-5 Thermoplastic insulated wires and cables for transmission and distribution of electrical energy.
23 ASTM-D-2843 Standard test method for density of smoke from burning/decomposition of plastics.
24 ASTM-D-2863 Test for determination of oxygen index.
Equipment and material conforming to any other standard, which ensures equal or better quality, may be accepted subject to approval of the Owner. In such case, copies of the English version of the standards adopted shall have to be submitted along with the bid.
The electrical installation shall meet the requirements of Indian Electricity Rules as amended upto date and relevant IS Codes of Practice. In addition, other rules and regulations applicable to the work shall be followed.
3.0 DESIGN CRITERIA
a) The cables shall be installed in hot, humid tropical atmosphere with ambient temperature of 45°C.
b) All MV cables shall be suitable for operation under the following voltage & frequency variations:
Voltage Variation : (±) 10%
Frequency Variation : (+) 3% to (-)5%
Combined Variation of Voltage & Frequency
: 10% (absolute sum)
c) MV cables shall be 33 kV & 11 kV of earthed grade suitable for use in solidly earthed system, stranded & compacted electrolytic aluminium conductor, extruded semi conducting screen over conductor, XLPE insulated, unarmoured as required, semi-conducting followed by copper tape screened, extruded PVC, Type ST–2 inner sheathed, overall FRLS, PVC outer sheathed, conforming to IS 7098 (Part II), IEC 60502 for constructional details and tests.
d) The LV power cables shall be 1100V grade, single/multi core stranded Aluminum conductor, extruded XLPE/PVC insulated with extruded PVC inner sheath, armoured and overall sheath with extruded Flame Retardant Low Smoke (FRLS) PVC compound (Type ST-1). These cables shall conform to IS 7098 (Part I) for XLPE and 1554(part 1) for PVC insulation.
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
e) The control cables shall be 1100 V grade, multi core, stranded annealed high conductivity copper with extruded PVC insulated inner sheath, armoured and overall sheath with extruded Flame Retardant Low Smoke (FRLS) PVC compound (Type ST-1).
f) The continuous and short time current carrying capacity of XLPE insulated cables shall be based on maximum operating temperature of 900C and 2500C respectively.
g) The continuous and short time current carrying capacity of PVC insulated cables shall be based on maximum operating temperature of 700C and 1600C respectively.
h) MV & LV power cables shall be sized taking into account the following derating factors:
i. Max Ambient air temperature
ii. Max Ambient ground temperature
iii. Grouping of cables/Method of laying
iv. Depth of laying for cable buried in ground.
v. Soil thermal resistivity for cable buried in ground.
i) MV cables shall be chosen taking into account the following factors:
i. System Fault level.
ii. Maximum time for fault clearance (i.e, operating time of the backup protection relays plus the time of operation of the circuit breakers).
iii. Full load current of the circuit.
iv. Short circuit current and duration (for breaker protected cables)
v. Installation conditions.
vi. Voltage drop under normal running and starting condition
vii. Voltage drop at motor terminals shall be within permissible limit during starting & normal running. i.e 5% during steady state and 15% during transient or starting at motor terminal.
viii. The cable should withstand the maximum fault current corresponding to the particular voltage level for the minimum time before the fault is cleared.
ix. Consideration shall also be given to limit the cable to the nearest standard sizes instead of using too many types.
x. The minimum size of LV cables to be used shall be as follow :
Aluminium conductor : 6 Sq. mm.
Copper conductor : 2.5 Sq. mm
4.0 SPECIFIC REQUIREMENT
4.1 Type of Cable
4.1.1 The MV cable shall be multi core/ single core XLPE insulated type as specified.
4.1.2 LV power cables shall be 1100V grade, heavy duty, stranded aluminium conductor, XLPE/ PVC insulated, extruded black FRLS PVC inner sheathed, unarmoured and overall FRLS extruded black PVC outer sheathed (Type ST-1) cables conforming to IS: 1554(Part 1)
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
for PVC insulation and IS 7098(Part 1) for XLPE insulation.
4.1.3 Control Cables shall be 1100 V grade, heavy duty with annealed high conductivity stranded copper conductor, PVC insulated, FRLS PVC inner sheathed, armoured and FRLS extruded black PVC outer sheathed (Type ST-1) cables conforming to IS : 1554.
4.1.4 LV power cables of size above 35 sq. mm may be provided with XLPE insulation. Bidder shall clearly indicate the type of insulation provided in the technical bid.
4.1.5 The instrumentation cables shall be annealed, tinned stranded copper conductor, 0.5 mm2, twisted into pairs, overall screened (L1 type) for digital signals, individual and overall screened (for L2 type) for low level analogue signals, individual triplet and overall screened (type L3), PVC insulated, inner PVC sheathed, GS wire armoured and overall sheathed with FRLS PVC. The insulation shall be strippable manually as well as by mechanical stripping devices without damage to the conductor.
4.1.6 Lighting Wires shall be 1100 V grade, single core, stranded, copper conductor, PVC insulated wires conforming to IS 694 / IEC 60227 Part 1 to 5 / IEEE-719. Minimum cross section of copper wires shall be 2.5 mm2 for lighting circuits and 4 mm2 for receptacle circuits.
4.2 Conductor
4.2.1 The cable conductor shall be made from standard Aluminum to form compact conductor having a resistance within the limits specified.
4.3 Conductor Shield
4.3.1 The conductor having a semi-conducting screen shall ensure perfectly smooth profile and avoid stress concentration. The conductor screen shall be provided over the conductor by applying non-metallic semi conducting tape or by extrusion of semi conducting tape or by extrusion of semi-conducting compound or a combination of the two. The semi conducting polymer shall be cross linked for XLPE cables.
4.4 Insulation
4.4.1 The insulation of the MV cables shall be XLPE type and LV power and control cables shall be [XLPE/PVC] type. It shall be designed and manufactured for the specified system voltage. The manufacturing process shall ensure that insulation shall be free from voids. The insulation shall withstand mechanical and thermal stresses under steady state and transient operating conditions. The extrusion method should give a very smooth interface between semi conducting screen and insulation. The insulation of the cables shall be of high standard quality.
4.5 Insulation Shield
4.5.1 A non magnetic semi conducting shield shall be put over the insulation to confine electrical field to the insulation. The XLPE cable insulation shield shall be strippable.
4.5.2 The metallic layer of the insulation shield shall be grounded at least at one location in the cable’s run. In the case of single conductor cable, care should be taken with regard to ampacity when grounding at more than one point.
4.5.3 For all the cables having insulation shield, it shall have some form of stress relief measure
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
at every splice at termination. This can be stress cones, moulded devices, heat shrink or cold shrink kits. All kits must be suitable for the voltage class and cable size.
4.6 Inner Sheath
4.6.1 The sheath shall be suitable to withstand the site conditions and the desired temperature. It shall be of adequate thickness and applied by a continuous process to produce a sheath of consistent quality free from all defects. PVC sheath shall be extruded with FRLS properties.
4.7 Outer sheath
4.7.1 Outer sheath shall be extruded layer of FRLS PVC compound (ST-1).Sheath shall be resistant to water, Ultra Violet radiations, fungus, termites and rodent attacks. The color of the sheath shall be black.
4.8 Packing
4.8.1 [Cables shall be supplied in non-returnable drums]. Drum lengths shall be such so that cable joints are totally avoided. The drums shall be of heavy construction. [All wooden parts shall be manufactured from seasoned wood.] All ferrous parts used shall be treated with suitable rust preventive finish or coating to avoid rusting during transit or storage. [Wooden cable drum shall be treated by immersing in copper-nitrate solution.]
4.8.2 The ends of each cable length shall be sealed before shipment. Heat shrinkable cable cap shall be used for this purpose.
4.8.3 [A label shall be securely attached to each end of the reel indicating the Purchaser's order number, Owner’s identification mark, length, type, voltage grade, conductor size and number of cores of the cable.] A tag containing the same information shall be attached to the leadings end of the cable inside. An arrow and necessary instructions shall be marked on the drum indicating the direction in which it should be rolled. Drum numbers are to be indicated on the cable drums. Drum length shall not be less than the following:
a) Power cables: 500m b) Control cables: 1000m
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
4.9 Identification of cores:
MV & LV power cables shall be identified by color code. However LV control cables shall be identified by the number of its cores.
[Multi-core control cables shall have 20% spare core, minimum one spare.]
4.10 Constructional Requirements
4.10.1 Cable shall have suitable filters laid up with the conductors to provide a substantially circular cross section before the sheath is applied. Fillers shall be suitable for the operating temperature of the cable and compatible with the insulating material. All materials shall be new, unused and of finest quality.
4.10.2 Workmanship shall be neat, clean and of the highest grade.
4.10.3 Special Properties:
All the above cables shall be conforming to the relevant Indian/IEC standard in general, with the following special properties:
a) Oxygen Index of the outer sheath shall not be less than 29, when tested as per ASTM-D-2863.
b) tested as per ASTM-D-2863.
c) Halogen acid contents in outer sheath shall not be more than 20%, when tested as per IEC-60754.
d) The maximum smoke density in percent light absorption should not exceed 60% in case of PVC compound and 20% in case of fire survival cables, when tested as per ASTM-D-2843.
e) Swedish chimney test as per SS-4241475 class F3 and ladder test for flammability as per IEEE-383.
f) The cables shall be tested for resistance to Ultraviolet radiation. The retention values of tensile strength and ultimate elongation after test shall be minimum 60% of tensile strength.
g) Outer sheath of cable shall be subject to tests for water absorption. The methodology shall be as per IS 10810 part 33.
4.11 Joints and Terminations
4.11.1 Materials of construction for a joint/termination shall perfectly match with the dielectric chemical and physical characteristics of the associated cables. The material and design concepts shall incorporate a high degree of operating compatibility between the cable and joints. The protective outer covering (jacket) used on the joints/terminations shall have the same qualities as that of the cable outer sheath in terms of ambient/operating temperature withstand capability and resistance to hazardous environments and corrosive elements. No joints shall be allowed unless the cable drawn length is exceeded.
4.12 Cable Identification
4.12.1 Cable identification shall be provided by embossing the following on the outer sheath:
a. [Manufacturer's name or trade mark
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
b. Voltage grade c. Year of manufacture d. Type of insulation. e. Type of outer sheath e.g. "FRLS" etc. f. ISI marks g. Nominal cross sectional area of the conductor & no of cores h. Sequential marking i. Owner’s identification mark]
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
4.13 Fire Proof sealing system
4.13.1 General
a) Fire proof sealing system shall consist of Fire-stops/fire-seals for sealing of cable/cable tray and conduit/pipe penetrations, both horizontal and vertical, through brick or RCC walls/floors, to prevent the spread of fire from one area, which is separated from others by fire-resistant barriers.
b) ‘Fire-breaks' provided on long runs of cable racks/trays to prevent the propagation of fire along the cable rack, within a single fire-area or fire- zone.
c) The FPS system shall also include all the necessary accessories and equipment required for supporting, holding in position, fixing and installation of the fire-stop/fire-break.
d) The FPS system shall comply in all respects with the requirements of the codes and standards listed below
a. IEEE-634 ASTM-E-814
b. ANSI-IEEE-383 IEC-331 IEC-332
4.13.2 Fire stop/ seal
The FPS system adopted for cables or cable trays penetrating through walls and floor constitute a openings, or cables passing through embedded conduits / pipes / pipe- sleeves, fire stop / seal', which is meant to prevent spreading of fire between areas separated by fire-resistant barriers.
4.13.3 Fire Break
The fire proofing system, other than fire-stops, adopted to retard flame propagation long runs of horizontal or vertical cable trays in the same fire zone or area, in an event of a fire, shall constitute a `fire-break' and shall be provided by applying a suitable fire –resistance coating on cables and cable trays for the required length, with or without a fire resistant panel, at the point of the fire break to obtain the fire-rating specified.
4.13.4 Application of fire proof sealing system
a) Fire stops shall be provided for cable penetration openings listed below.
b) The passage of cables/cable trays pipe sleeves/embedded conduits through walls / floors.
c) Vertical raceways, which carry cables between successive floors, through openings provided in the RCC floor slab, shall be sealed by fire stops at each floor level.
d) Cable entry through openings in floor slabs below HT/LT switchgear, MCCs, various Control and relay panels and other bottom entry panels, shall be effectively sealed by fire stop
e) Location of fire breaks
f) Firebreaks shall be provided on both cable rack and trenches at all cable tray Intersections and tee-offs.
g) On linear runs of cable trays between fire stops or fire breaks, fire breaks shall be provided at intervals of 15 metres on horizontal cable runs and 5 m on vertical cable runs.
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
h) Fire breaks in linear runs of cable trenches between intersections and tee-offs shall be provided at intervals of 30 metres.
i) Bidder shall furnish the test certificates for the fire stops and fire breaks after award of contract for Owner/Owner’s Representative review. If the certificates are not satisfactory all the tests shall be conducted free of cost. The offered system i.e. fire stops and fire breaks shall be identical (or better) with the system which is successfully type tested for the specified rating i.e. the composition density of the material, thickness of coating in case of fire breaks and any other properties of the material / system offered shall be identical or better than the tested system and shall be subject to Owner / Owner’s Representative.
4.13.5 Test on fire stops
i. The fire stops shall be subjected to the following type tests:
a. Fire Rating Test
b. Hose Stream Test
ii. Type tests shall be conducted on different fire stop test specimens described above as per IEEE-634. The sizes of the fire stop test specimens shall be similar to the largest of the sizes being used in the plant.
iii. Preconditioning of fire stop test specimens before conducting the fire rating and hose stream tests, each test specimen shall be preconditioned for thermal ageing, water immersion and vibration.
iv. Test on Fire Stops
v. During the fire rating test, the transmission of heat through the cable penetration fire stop shall not raise the temperature on its unexposed surface above the self ignition temperature of the outer cable covering, the cable penetration fire stop material, or material in contact with the cable penetration fire stop, with a maximum temperature limit on the unexposed surface of 200°C.
vi. Tests on fire breaks
vii. Firebreaks shall undergo the following tests as per ANSI-IEEE-383:
a. Ampacity test
b. Flame test
5.0 CABLE CHARACTERSTICS
5.1 CABLE INSTALLATION
5.1.1 Core screen will be earthed at both ends and cables will be laid in duct buried underground.
5.1.2 In addition the Bidder shall advise rating/derating factors for variations in the above conditions as well for multiple circuits.
5.1.3 Permissible minimum bending radius of power cables during laying:
5.1.4 During pulling of power cables, the bending radius should not fall below the values listed.
5.1.5 In the case of single bends (placing cables in final position), the above values may be reduced to a minimum of 20 x cable outer diameter (Milliken and stranded conductors) or
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
even 15 x cable outer diameter (solid conductors)
5.1.6 During laying of power cables, particular attention must be paid to the permissible tensile force, as follows:
Permissible tensile forces when using cable pulling grips:
F = 2 x D2 in N for cables with copper wire sheath
F = 2 x D2 in N for cables with sheath.
D represents the cable outer diameter expressed in mm
5.1.7 Maximum recommended tensile forces when pulling eye is attached to the conductor:
Alu stranded: F = A x 30 N/mm2
Alu solid: F = A x 20 N/mm2
Alu Milliken: F = A x 30 N/mm2
Cu stranded: F = A x 50 N/mm2
Cu Milliken: F = A x 80 N/mm2
A represents the cross-sectional area of conductor expressed in mm2.
5.2 SIZES OF UG CABLES REQUIRED
Voltage rating Cross sectional area.
33kV 300mm² Aluminium Cables
11kV 400mm² and 240mm², Aluminium Cables
6.0 INSPECTION
6.1.1 Before dispatch the cables offered shall be made available for inspection by the Engineer. Inspection may also be made at any stage of manufacture at the option of the purchaser and the cables found unsatisfactory due to the material used or poor workmanship shall be rejected.
6.1.2 The contractor shall guarantee free access to the places of manufacture to the Engineer at all times when the work is in progress. The contractor shall inform the Engineer in advance the time of starting of manufacture and the progress of manufacture of the cables offered by him so that arrangement can be made for inspection.
6.1.3 Inspection and acceptance of cables by the Engineer shall not relieve the contractor of his obligation of furnishing cables in accordance with the specification and shall not prevent subsequent rejection if such cables are later found to be defective.
6.1.4 The cables shall comply with type tests stipulated in prescribed section and the relevant standards. Test reports for all type tests shall be submitted with the tender.
6.1.5 All type and sizes of cables shall be subjected to routine and acceptance tests as stipulated in relevant standards without any extra cost to the purchaser. Cables should not
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
be dispatched until the test reports are duly approved by the Purchaser or his authorized representative and specific instructions to despatch the inspected items issued.
6.1.6 The purchaser reserves the right of having any other special tests of reasonable nature carried out at site or at manufacturer's works or at any other place in addition to the aforesaid type and routine tests to satisfy himself that the cables comply with the specification, without any financial liability.
6.1.7 Six copies of test reports (or as indicated in the Schedule of Vendor Drawings) shall be supplied for approval. The reports shall indicate clearly the governing standards and the standard values specified for each test to facilitate checking of the test reports. Six bound copies of the test reports shall be submitted after approval of test reports along with the cables.
7.0 Tests
7.1 Type Test
7.1.1 For each type & rating of HV cables, the Bidder shall submit for Owner’s approval the reports of all the type tests as per relevant standards and carried out within [last five] years from the date of bid opening. These reports should be for the tests conducted on the equipment similar to those proposed to be supplied under this contract and the test(s) should have been conducted at an independent laboratory.
7.1.2 In case the Bidder is not able to submit report of the type test(s) conducted within last five years from the date of bid opening, or in case the type test report(s) are not found to be meeting the specification requirements, the Bidder shall conduct all such tests under this contract free of cost to the Owner and submit the reports for approval.
7.1.3 The list of type tests are as follows:
i. Tests on conductor:
a. Annealing test (for copper)
b. Tensile test (for aluminum)
c. Wrapping test (for aluminum)
d. Conductor resistance test.
ii. Test for armouring wires/strips
iii. Test for thickness of insulation and sheath
iv. Physical tests for insulation and outer sheath:
a. Tensile strength and elongation at break
b. Ageing in air oven
c. Shrinkage test
d. Hot deformation
e. Loss of mass in air oven
f. Heat shock test
g. Thermal Stability
TECHNICAL SPECIFICATION FOR POWER AND CONTROL CABLES
ABD, Ranchi Smart City
v. Insulation resistance test
vi. High voltage test (water immersion test)
vii. High voltage test at room temperature
viii. Flammability test
7.2 Routine Test
7.2.1 Cables shall be subject to acceptance and routine tests as per IS codes. Acceptance tests and FRLS test as specified earlier shall be conducted on cables and the same shall be witnessed by purchaser.
7.2.2 The FRLS test shall be carried out on one cable of each batch of compound used. Other acceptance tests shall be carried out on drums selected as per sampling plan as indicated in IS. Test certificates for routine acceptance and special tests shall be furnished by the Bidder for review and approval of purchaser.
7.3 Drawings, Data and Manuals
7.3.1 The following drawings/documents and calculation as listed below but not limited to shall be furnished along with the bid for review
[Cable datasheets and cross sectional drawings]
[Cable sizing calculation]
[QAPs & Test Reports]
[Relevant catalogues]
[Estimated weight of cable and cable drum]
TECHNICAL SPECIFICATION
FOR EARTHING & LIGHTNING PROTECTION SYSTEM
Contents
1. EARTHING AND LIGHTNING PROTECTION SYSTEM ............................................................. 3
1.1 General ..................................................................................................................................................... 3
1.2 Codes and Standards ................................................................................................................................. 3
1.4 Specific requirements ................................................................................................................................ 4
1.6 Drawings, Data & Manuals ...................................................................................................................... 14
1.7 Rating and Requirements ........................................................................................................................ 14
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
1. EARTHING AND LIGHTNING PROTECTION SYSTEM
1.1 General
This specification is intended to cover the [design, Engineering, manufacture, assembly,
testing at manufacturer's works, supply in properly packed condition for transport to
site, Erection, site testing and commissioning] of Earthing and Lightning Protection
System.
The system shall be complete in all respect including all accessories required for efficient
and trouble-free operation of Ranchi Smart City, Jharkhand
1.2 Codes and Standards
All equipment and materials shall be designed, manufactured and tested in accordance
with the latest applicable Indian Standards (IS) / IEC as given below except where
modified and/or supplemented by this specification.
Table 1.0
IEC 62305-3 Protection against lightning – Physical damage to structures and life
hazard
IS:2629 Recommended practice for hot dip galvanizing of iron & steel
IS:2633 Method for testing uniformity of coating on zinc coated articles.
IS:3043 Code of practice for Earthing
IS:9537 Conduits for electrical installation.
IEEE:80 IEEE guide for safety in AC substation grounding
IEEE:142 Grounding of Industrial & commercial power systems
CEA CEA Regulations and standard technical specification for main plant
package.
Equipment and material conforming to any other standard, which ensures equal or
better quality, may be accepted. In such case, copies of the English version of the
standard adopted shall be submitted along with the bid.
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
The electrical installation shall meet the requirements of Indian Electricity Rules as
amended up to date and relevant IS Code of Practice. In addition, other rules and
regulations applicable to the work shall be followed.
1.3 Design Criteria
a) Earthing system design shall consist of earth grids and electrodes buried in soil in
the whole substation area, embedded in concrete inside all the buildings to which
all the electrical equipment, metallic structures are connected to have earth
continuity for safety reasons.
b) The main objectives of earthing system is to:
1. Provide safety to personnel from contact of dangerous potential caused by
ground fault.
2. Ensure sufficient grounding current for effective relaying.
3. Stabilize circuit potential with respect to ground.
c) The earthing conductor shall be designed for fault current of [26.2 kA] for duration
of 1 second.
d) It is the responsibility of the Bidder to undertake the soil resistivity measurements
at site and select suitable size of conductor based on the soil resistivity.
e) Ground conductor shall be of galvanized iron for above ground and mild steel for
embedded and below ground earthing.
f) Main earth grid conductor shall be mild steel (MS) of [32] mm dia.
g) Suitable corrosion allowance shall be considered over ground conductor size
depends upon soil resistivity.
h) The main purposes of lightning protection system are to :
1. Provide protection to structures from lightning strokes.
2. Provide a low resistance-conducting path to lightning discharge.
1.4 Specific requirements
1.4.1 Scope of Work
The scope of work shall include Design, supply, unloading at site, storing, laying, fixing,
jointing/termination, erection, testing and commissioning of equipment associated with
the safety earthing and Lightning Protection system for following areas Listed below but
not limited to the following:
[Note: With reference to particular package, scope of work shall be modified.]
a) 33/11kV Substation Building:
i) Earthing and lightning protection system for Transformer area, Switchgear
Room, Control rooms, all roads within battery limit etc.
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
ii) For all above areas, above ground Earthing and Lightning protection system
shall be provided.
iii) System Neutrals are earthed through Treated Earth Pit. All areas of
substation are interconnected to form an integrated single earthing system.
1.4.2 Earthing system
a) Earthing system shall be designed in accordance with IS 3043 and Indian Electricity
Rules and Acts.
b) Fault current for the earthing system shall be designed for [26.2] KA for duration of
1 sec.
c) All electrical equipment, non-current carrying metal parts, structures, building steel,
lightning protection system, transformer neutrals shall be connected to station
ground grid.
d) Treated earth pits including riser shall be provided for transformer neutral earthing.
e) Connection between the equipment earth lead and the grid conductor shall be
welded. For rust protection, the welds shall be treated with zinc chromate primer
and coated with zinc rich paint.
f) Entire erection of grounding work shall be carried out in such a way as to be capable
of withstanding the intended services of carrying full short circuit level currents to
ground mat without any damage/deformation.
1.4.3 Ground Grid Conductor
a) Ground grid conductor of mild steel rod shall be used.
b) However bidder shall consider as per CBIP norms Manual on Earth mat design the
corrosion allowance as below:
For soil resistivity greater than 100 ohm-meter: No allowance.
For soil resistivity greater than 25- 100 ohm-meter: 15% allowance.
For soil resistivity less than 25 ohm-meter: 30% allowance.
1.4.4 Underground Grid
a) The ground grid mesh is designed to keep the touch and step voltages within safe limits
as per recommendation of IEEE 80.
b) [The ground grid conductors shall be buried in earth at a depth of 600 mm]. The
length of ground conductors below earth shall be sufficient to ensure a ground resistance
less than one (1) ohm.
c) The ground grid conductor shall be so laid as to provide short and direct connection to
building steel and major electrical equipment.
d) Ground rods shall be provided at the points where system neutrals/lightning protections
are connected to the ground grid.
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
e) All ground grid conductor connections shall be welded type.
f) Ground grid shall be interconnected with the ground grid of neighboring areas at least at
two (2) points for further reducing the ground grid resistance.
g) A minimum earth coverage of [300] mm shall be provided between the ground grid
conductor and the bottom of trenches, tunnels, underground pipes, foundations, railway
tracks etc. The ground grid conductor shall be re-routed in case it fouls with equipment
foundations.
h) In some cases, it may happen that the construction work of cable trench, foundation and
laying of underground pipes are being taken up after the grounding mat has been laid. It
may be required to cut a portion of grounding conductor to avoid fouling with cable
trench, equipment foundations, underground pipes etc. In this case, the ground
conductor shall be properly rerouted and rejoined/reconnected with the main grounding
mat during the construction/laying of above underground objects and good electrical
continuity of grounding conductor shall be ensured.
i) Grounding conductors crossing the road may have to be laid at greater depth to suit the
site conditions.
j) The Bidder shall carryout the grounding of all electrical equipments and connection to
main earth grid.
1.4.5 Ground Electrode
Ground electrodes shall be [40] mm dia. and [3] metre long M.S. rod. These are to be
fabricated and driven into the ground by the side of mat conductors. All connections to
the conductors shall be done by arc welding process.
1.4.6 Above Ground Connections
a) Galvanized iron flats shall be used for all connections above earth.
b) Inside building, ground conductors shall be run for each floor supported on building steel
and/or cable trays. These ground conductors in turn shall be connected to the station
ground grid through riser (at least two) coming up along building columns/cable shafts.
c) Two separate and distinct ground connections shall be provided for each electrical
equipment in compliance with I.E. Rules.
d) All steel columns and structures shall be connected to the earth mat through earth
leads.
All connections above ground shall be welded type except connection to
equipment/structures which shall be bolted type.
1.4.7 Risers
Risers are required for connecting the equipment and structures with the ground mat.
Risers are to be provided from underground mat to above ground levels where the ends
shall be left free for connecting to the equipment. Each riser shall be 1 No. [40] mm dia.
M.S. rod and shall project above grade level/concrete floor level by minimum 300 mm.
They are to be clamped or supported along the outer edge of the concrete foundation.
Connection to the ground mat shall be done by arc welding.
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
1.4.8 Equipment Ground Lead
a) Equipment ground connections shall be sized to carry the ground fault current.
Considerations shall also be given to mechanical ruggedness of the connections and to
limit the number of sizes.
b) The minimum ground conductor sizes for various equipment and structures are given in
below.
Table 2.0
DESCRIPTION SIZE MATERIAL
a) Main Grounding Grid Conductor [32] mm dia Rod Mild Steel
b) Riser/Pigtail From Grounding Grid/Mat [40] mm dia Rod - Galvanised Iron -
c) Electrode [40] mm dia, [3000]
mm long Rod
- Mild Steel -
d) Conductor used for connection of various equipment/structures as listed below
Structures, Control Panels, Cable Trays etc. [50 x 6] mm Flat –Galvanised Iron
415V Power Control Centres, Motor
Control Centres, Distribution Boards etc.
[50 x 6] mm Flat - Do -
Local Panels, Lighting Panels [25 x 6] mm Flat - Do -
Motors :
Above 90 kW [50 x 10] mm Flat Galvanised steel
Above 30 kW Upto 90 kW [25 x 6] mm Flat - Do -
Above 5 kW Upto 30 kW [25 x 3] mm Flat - Do -
Upto 5 kW [8] SWG - Do -
Miscellaneous Items, viz. Push Button
Station, Junction Boxes etc
[8] SWG - Do -
{The Above size of Earth flat is indicative only. Bidder shall refer Volume II Section I for
size of earth flat used for existing plant or as per design.}
1.4.9 Jointing and Connection
a) All ground conductor connections below ground level shall be done by electric arc
welding with low hydrogen content electrode. The contact surfaces shall be thoroughly
cleaned to provide good electrical continuity.
b) The bending of the large diameter ground conductor where necessary shall be done by
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
gas heating.
c) The projected portion of riser/pigtail above ground shall be coated with two coats of
bitumen paints (anti-corrosive paints) with a minimum thickness of 1 mm after
connection.
d) The connections between the riser/pigtail and earthing conductors (galvanized iron flats)
and between the earthing conductors above ground level shall be made by electric arc
welding.
e) The earthing connections to equipment grounding pads/terminals and some removable
structures shall be bolted type with GI bolts and nuts. The contact surfaces shall be
thoroughly cleaned (to free from scale, paint, enamel, grease, rust) before connection to
ensure good electrical contact.
f) Equipment/structures ground connections shall be coated with weather resistant
paints/cold galvanizing paints after proper checking / testing.
g) Whether specifically shown or not, all conduits, trays, cable armour and cable end box,
electrical equipment such as motors, switchboards, panels, cabinets, junction boxes,
lockout switches, fittings, fixtures, etc. shall be effectively grounded.
1.4.10 Earthing system installation
a) The spacing between two electrodes shall be at least equivalent to twice the length of
the electrode.
b) Earthing conductor running exposed on column, walls, etc., shall be supported by
suitable cleating, at intervals of 750 mm.
c) The earthing conductor crossing the road / track shall be laid in hume pipe or laid at
a greater depth to avoid damage.
d) When earth conductor passes through floors, walls, etc. suitable pipe sleeves shall
be provided and the same shall be sealed after installation.
e) The connection between earthing pads / terminal to the earth grid shall be made
short and direct and shall be free from kinks & splices.
f) Metallic conduits and pipes shall not be used as earth continuity conductor.
g) Street lighting poles, flood light poles & towers, their junction boxes shall be
connected to the earthing conductor to be run along with supply cable. This earth
conductor shall be in turn connected to earth grid at two extreme points.
h) The steel columns, metallic stairs, hand-rail etc. of the building where electrical
equipment are located shall be connected to the nearby ground mat by earthing
conductor. Electrical continuity shall be ensured by bonding the different sections of
handrails and metallic stairs.
i) Fence within the ground grid shall be bonded to the plant ground system at regular
interval not exceeding ten [10] metres. Fence gate shall be separately grounded with
flexible connection to permit movement.
j) [50 x 10] mm galvanized iron flats(minimum size) shall be run as main earthing
conductors above ground along building columns, walls, steel structure, etc. for
equipment and other structures earthing. These earthing conductors shall be
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
interconnected between them and to the main ground grid through risers/pigtail. The
connection between earthing conductor and riser shall be made above ground. Earthing
conductors can be embedded in concrete floor of the building wherever necessary
without having direct contact with the reinforcement rods. At the crossing of building
walls, floors etc. the earthing conductor shall be passed through galvanised conduit
sleeves. Both ends of the sleeve shall be sealed to prevent the passage of water through
the sleeves.
k) All indoor and outdoor electrical equipment and associated non-current carrying metal
works, supporting structures, building/ boiler columns, fence, system neutrals, lightning
masts/arresters shall be connected to the substation ground system.
l) Miscellaneous devices such as junction boxes, pull boxes, pushbutton stations, lockout
switches, cable end boxes, lighting fixtures, receptacles, switches etc. shall be effectively
grounded whether specifically shown or not.
m) Metallic conduits and pipes shall not be used as earth continuity conductor. These shall
be grounded at both ends.
n) A continuous [50 x 6] mm (minimum size) G.I. flat earthing conductor shall run along the
cable trays and supporting structure of all cable routes. This earthing conductor shall be
attached to each section of cable tray/trays through [50 x 10] mm G.I. flats. The earthing
conductor shall be securely connected to the earth mat at both ends.
o) Flexible earth conductors shall be provided at expansion joints for earthing the
gates, operating handles, etc.
p) Equipment bolted connection after being checked and tested shall be painted with
anti-corrosive paint / compound.
q) Connection between the equipment earth lead and the grid conductor shall be
welded. For rust protection, the welds shall be treated with zinc chromate primer
and coated with zinc rich paint.
r) The cable sheaths, screens armour shall be earthed at both ends for multi-core
cables. For single core cables the same shall be done at one end (switchgear end)
only.
s) All bimetallic connections shall be treated with suitable compound to prevent
moisture ingression.
t) Main plant earth grid and switchyard earth grid shall be interconnected each other
by minimum two numbers of leads.
1.4.11 Lightning Protection System Design
a) Lightning protection system shall consist of vertical air termination rods, horizontal
roof conductors, down conductors and pipe electrodes.
b) The need for providing the lightning protection system shall be established by
calculating risk index value for each building structure, etc., as per procedure given
in IEC 62305-3 and any building whose risk index is more than value specified in IS
shall be provided with lightning protection. However, Substation building,
switchyard building shall be provided with lightning protection irrespective of the
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
arrived risk index.
c) Shielding angle for one vertical air termination shall be 45 degrees. For more than one
rod, shielding angle between the rods shall be taken as 60 Degrees.
d) Down conductors shall run along the outer surfaces of the building and shall have a test
joint about 1500 mm above ground.
e) A Lightning electrode shall be provided at the connection point of the down conductor
with the station ground.
f) Galvanized steel rods and flats shall be generally used for air termination and
connections. All connections shall be welded type.
1.4.12 Air Terminations
a) The projected length of the Air termination rod shall be as required to protect the object
(on which the rod is fixed) from lightning stroke.
b) The air terminal rod shall be properly fixed on the top of the building/structure to
withstand very high wind pressure. In case the air terminal rod is embedded at the top of
roof of building, the portion embedded inside the concrete shall not touch the
reinforcement bars and shall be duly insulated from them.
c) All the vertical air terminal rods shall be electrically connected together by means of
horizontal conductors of size [25 x 6] mm galvanized iron flats.
1.4.13 Down Conductors
a) Galvanized steel down conductors of suitable size [25 x 6] shall be connected with
air terminal rod/horizontal conductor at the top of roof/structure and other end
connected to the nearest 40 mm dia. mild steel rod riser from ground electrode.
b) Each down conductor shall have an independent earth termination. In no case
conductors of the lightning protection system shall be connected with the
conductor of grounding system above ground level.
c) The connection between each down conductor and rod electrode (by means of 40
mm mild steel rod riser) shall be made by others. However Bringing down comer
with test link at a level of 1500mm approximately from above ground level shall be
boiler contractor scope of work.
d) The down conductor shall be laid straight and sharp bends shall be avoided as far as
practicable. These shall be cleared on outside of the building wall and
column/structure at about 750 mm intervals unless stated otherwise in the drawing.
e) At all supports for down conductor along the column/wall of the buildings etc. the
portion embedded inside the building concrete should not touch the reinforcement
bars.
f) All exposed metallic parts of the buildings shall be bonded to the down
conductors. Such parts shall include ladders, balconies, conduits etc.
g) The down conductors shall be protected at the ground level against mechanical
injury by means of non-metallic pipes, viz. PVC pipes filled with bituminous
compound.
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
1.4.14 Electrodes (for Lightning Protection)
The electrodes shall be [40 mm] diameter [3000 mm] long mild steel rod. These shall be
driven into the ground.
All the electrodes shall be interconnected by means of one (1) [40 mm] dia mild steel
rod which shall be laid under ground at a minimum depth of [600 mm] below finished
grade level unless stated otherwise. This ground mats/electrode in turn shall be
connected to main grounding grid.
1.4.15 Riser (for Lightning Protection)
All risers connected to grounding mat shall be [40 mm] mild steel rods and shall be
projected 300 mm above grade level unless stated otherwise.
1.4.16 Jointing & Connection
a) All ground conductor connections below ground level shall be done by electric arc
welding with low hydrogen content electrode.
b) The projected portion of riser above ground shall be coated with two (2) coats of
bitumen paints (anti-corrosive paints) with a minimum thickness of 1 mm after
connection.
c) The joints in the lightning conductors shall be kept to a minimum and there shall be
no joint in the underground portions of conductors.
d) All the joints shall be done by arc welding process overlapping of the conductors
at straight joints shall not be less than 150 mm. The contact surfaces shall be
cleaned properly before jointing.
e) The portion of galvanized iron flats, which undergoes welding at site, shall be coated
with two (2) coats of cold galvanizing anti-corrosive paint after welding.
f) The bolted joint of the test link shall be covered with thick coating of bitumen paint
after successful testing.
g) The air terminal rods and shielding mast shall be coated with weather resistant anti-
corrosive paint (zinc chromate followed by two coats of aluminium paint).
h) The steel to copper connection shall be brazed type.
i) The lightning protection of inflammable liquid storage tanks wherever required,
shall be provided with horizontal conductors strung between tall poles covering the
entire zones or with air terminal rods mounted on top of poles/structure. These
horizontal conductors/vertical air terminal rods shall be connected to rod
electrodes, which in turn shall be connected to station ground mat.
j) The sizes and materials of earthing conductors to be used in lightning
protection system are listed below :
Table 3.0
DESCRIPTION SIZE MATERIAL
a) Vertical Air Termination [20] mm dia Rod Galvanised steel
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
b) Horizontal Conductor ------do-----
[ 25 x 6] mm Flat
c) Down Conductors ------do-----
[25 x 6 ] mm Flat
d) Ground electrode / riser [40] mm dia Rod Mild Steel
e) Interconnection with earth mat [40 ] mm dia Rod Mild Steel
1.5 Tests
I) Type Test
The Bidder shall submit for Owner’s approval the reports of all the type tests as per
relevant standards and carried out within last [five] years from the date of bid opening.
These reports should be for the tests conducted on the equipment similar to those
proposed to be supplied under this contract and the test(s) should have been conducted
at an independent laboratory.
In case the Bidder is not able to submit report of the type test(s) conducted within last
[five] years from the date of bid opening, or in case the type test report(s) are not found
to be meeting the specification requirements, the Bidder shall conduct all such tests
under this contract free of cost to the Owner and submit the reports for approval.
II) Routine Test
All equipment shall be completely assembled, wired, adjusted and routine tested as per
relevant IS / IEC Standards at manufacturer's works/site in the presence of consultant
/purchaser or his representative.
The following test shall be conducted:
a) Measurement of earth resistance for each electrode.
b) Measurement of total earth resistance.
c) Measurement of earth loop resistance for E/F path of biggest LV drive.
d) Check tightness of all earth connections
e) Check earthing of all metallic equipments, cable trays, bus bar supporting
structures, building column (if steel all elect equipments, pipe lines etc. as per
the drawing / specification)
III) Test Witness
[The tests shall be carried out in presence of the Owner’s representative, for which a
minimum 7 days notice shall be given by the Bidder. The Bidder shall obtain the Owner’s
approval for the type test procedure before conducting the type test. The test procedure
shall clearly specify the test set-up, instruments to be used, procedure, acceptance
norms, recording of different parameters, interval of recording, precautions to be taken
etc. for the type test(s) to be carried out.]
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
IV) Test Certificates
a) Certified copies of all tests carried out at works and at site shall be furnished in
requisite no. of copies for approval of the Owner.
b) The equipment shall be dispatched from works only after receipt of Owner's written
approval of shop test reports.
1.6 Drawings, Data & Manuals
Drawings, data & manuals for the motors shall be submitted as indicated below:
a) [Earthing Material like conductor, flat, welding description etc.]
b) [Air termination rod and its accessories etc.]
c) [Technical Data sheets for Earthing and Lightning system].
1.7 Rating and Requirements
Major technical parameters of motor are listed below. However, Bidder may also refer
to Volume-III, technical schedule in order to submit technical data of equipment along
with their technical proposal.
S.NO. DESCRIPTION UNIT DATA
1.0 EARTHING SYSTEM
1.1 Manufacturer Name
1.2 Main ground grid conductor material & size
1.3 Ground electrode material & size
1.4 Riser material & size
1.5 Grounding installation work carried out as per
pecification
Y/N
2.0 LIGHTNING PROTECTION SYSTEM
2.1 Manufacturer Name
2.2 Vertical air termination conductor material & size
2.3 Horizontal air termination conductor material & size
2.4 Down Conductor material & size
2.5 Electrode material & size
2.6 Riser conductor material & size
Tender Specification for EARTHING & LIGHTNING PROTECTION SYSTEM
ABD, Ranchi Smart City
S.NO. DESCRIPTION UNIT DATA
2.7 Lightning Protection work carried out as per
specification.
Y/N
TECHNICAL SPECIFICATION
FOR 415V SWITCHGEAR, APFC PANEL, MCC AND DB
Contents
1. 0 415V SWITCHGEAR, APFC PANEL, MCC AND DB ................................................................. 3
1.1 General ..................................................................................................................................................... 3
1.2 Codes and Standards ................................................................................................................................. 3
1.4 Specific Requirements ............................................................................................................................... 8
f) Reversing contacts shall be electrically and mechanically interlocked.
g) Contactors with delayed dropout feature shall be provided for some essential
auxiliaries. These contactors shall not dropout on power failure if the voltage is
restored within 3 seconds.
1.4.6 Electronic over load relays
a) Electronic overload relays shall conform to IEC:292-1 and shall be triple pole,
ambient temperature compensated with adjustable setting, inverse time lag, built in
single phase preventer and hand/auto reset type provided as per requirement along
with necessary command, feedback cable, coupling relays etc.
b) Provided with 1 NO and 1NC contact of rating same as the auxiliary contact of the
contactors.
c) The relay shall be able to withstand prospective short circuit current without
damage or injurious heating till the motor protection MCCB/MPCB clears the fault.
d) Relays may be direct acting or CT operated, depending on current rating. CTs shall
be included in the scope of supply.
1.4.7 Bus Transfer scheme:
Each switchgear of two incomer and bus coupler shall be provided with the following
provisions.
i) Dead bus closing.
ii) Manual live change over (Momentary paralleling)
iii) Automatic bus transfer scheme.
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
1.4.8 Current Transformer
a) Current Transformers shall be cast-resin type. All secondary connections shall be
brought out to terminal blocks where wye or delta connection shall be made.
b) CTs shall have polarity makings indelibly marked on each transformer at the lead
terminations and at the associated terminal block. Facility shall be provided for
short circuiting and grounding the CT secondary at the terminal blocks. Secondary
terminals shall be provided with protective cap.
c) CT terminal block shall be disconnecting type and suitable for round type lugs with
facility for testing and short circuiting of individual CT.
d) All CTs shall be provided with supports independent of busbars / busbar supports.
The CTs shall be located in such a way that they can be easily approached for
maintenance without necessitating shutdown of adjacent feeders.
e) CTs shall be provided with disconnected type test links in both secondary leads for
carrying out current and phase angle measurement.
1.4.9 Voltage Transformer
a) Voltage transformers(VT) shall be cast-resin type with an accuracy class of 1.0 for
metering and 3P for protetction.
b) VTs shall be of the single-phase type. VTs shall be protected on their primary side by
MCCBs with interrupting ratings corresponding to breaker rating and by MCB (with
auxiliary contacts) on the secondary sides.
c) VTs shall have continuous over voltage factor of 1.2 and short time over voltage
factor of 1.5 for 30 seconds for effectively earthed system
d) It shall be possible to replace VTs without having to de-energise the main busbars.
e) VTs shall be provided with disconnected type test links in both secondary leads for
carrying out current and phase angle measurement.
1.4.10 Transducer
For all the incoming and the outgoing of 415V Switchgear / MCC/ DB Feeders requiring
remote metering and/or current monitoring shall be provided with multi-functional
transducers. The output shall be 4-20 mA DC which shall correspond to the normal
range.
1.4.11 Secondary Wiring
a) The switchgear shall be fully wired at the factory to ensure proper functioning of
control, protection and interlocking schemes.
b) Fuse /MCB and links shall be provided to permit individual circuit isolation from bus
wires without disturbing other circuits. All spare contacts of relays, switches and
other devices shall be wired up to terminal blocks.
c) Secondary wiring within the switchgear shall be carried out in a neat and systematic
manner and securely held in position (either loomed or run in conduit / trunking).
Wherever wiring passes through compartment, it shall be run in conduit / trunking,
if metallic shall be bonded to the main earth busbar.
d) Wiring shall be done with flexible, 1.1/0.650kV grade, PVC insulated switchboard
wires with stranded copper conductors of 2.5 mm2 for CT & PT circuits and 1.5mm2
for control circuit wiring.
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
e) Each wire shall be identified, at both ends, with permanent markers bearing wire
numbers as per bidder s wiring diagrams. Wire terminations shall be made with
crimping type connectors with insulating sleeves, wire shall not be spliced between
terminals.
1.4.12 Terminal Blocks
a) Terminal blocks shall be 660V grade box-clamp type with marking strips, similar to
10 mm2 or equal. Terminals for C.T. secondary leads shall have provision for
shorting.
b) Not more than two wires shall be connected to any terminal. lf more than two wires
at one terminal are required, separate terminals with function wise shorting links
shall be provided. Spare terminal equal in number to 20% of active terminals shall
be furnished.
c) Terminal blocks shall be located to allow easy access. Wiring shall be so arranged so
that individual wires of an external cable can be connected to consecutive terminals.
1.4.13 Ground bus
a) A ground bus, rated to carry maximum fault current, shall extend full length of the
switchgear. The ground bus shall be provided with two-bolt drilling with G.I. bolts
and nuts at each end to for connection to the grounding conductor / flat.
b) Each unit shall be connected directly to the ground bus. The frame of each circuit
breaker and V.T. unit shall be grounded through heavy multiple contacts at all times
except when the primary disconnecting devices are separated by a safe distance.
c) C.T. & V.T. secondary neutrals shall be earthed through removable links so that
earth of one circuit may be removed without disturbing others. All hinged doors
shall be earthed by flexible copper bride.
1.4.14 Space Heater
a) Each vertical section shall be provided with thermostat controlled space heater 5A,
3 pin socket plug.
b) In addition, motor feeders rated 30 KW and above shall be wired up for feeding the
motor space heater through suitably rated breaker auxiliary NC contact and/or
contactor.
c) Cubicle heater, Motor heater, and Plug socket circuit shall have individual switch
fuse units/MCB.
1.4.15 AC Distribution Boards (ACDBs)
a) AC Distribution Boards shall have MCCB/MCB at incomer depending upon the short
circuit rating. Distribution Boards may be fed from switchgear and shall have two
incomers. AC distribution Boards shall be of two types - one with 415V, 4-wire, triple
pole and neutral (TPN) outgoing feeders and the other with 240V, 2-wire, single pole
and neutral (SPN) outgoing feeders.
b) For small loads, MCB boards with TPN MCB as incomer and TPN/SP MCBs for
outgoing may be considered. The feeder rating and quantity shall be as per
requirement.
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
c) Board shall be single front, metal clad, front matched, dust and vermin proof, fixed
type, compartmentalized and extensible on both sides.
d) Bus bars shall have same cross section throughout the length. Rating of the neutral
bus bar shall be 50% of the main bus bar. Earth bus bar shall run in bottom
chamber throughout the length of the Board.
e) Switches/MCBs/RCBOs shall be hand operated, air break, quick make, quick break
type conforming to applicable standards.
f) The feeders shall be protected for short circuit by fuse and the MCB shall be
provided with overload/short circuit protective device for protection under overload
and short circuit conditions.
g) Switch shall have provision for locking in both fully open and closed positions.
h) MCBs/RCBOs shall be provided with locking facility.
i) Receptacle units shall consist of socket outlet with associated switch, neon
indicating lamp and plug. The socket outlet and switch or MCB shall be flush
mounted within a stove enameled / galvanised 1.2 mm thick CRCA sheet steel
enclosure with Perspex /insulating cover. The box may be recessed into or mounted
on a wall as per requirements of project layouts.
j) The outdoor type receptacles shall be housed in a 2 mm thick CRCA sheet steel
epoxy painted enclosure with gasketed, hinged door having locking arrangement.
The enclosure shall be with rain canopy and removable gland plate entry from
bottom. Composite receptacle with switch modules housed in a box shall be with
degree of protection IP 65.
k) Single phase receptacles shall be associated with a switch/MCB of same current
rating and the receptacle shall become live only when the associated switch/MCB is
in ON position.
l) Three phase receptacles shall be associated with a TPN switch housed in the same
enclosure. The receptacle shall become live only when the associated switch is in
ON position and it shall not be possible to withdraw the plug with the switch in
ON position.
m) The plugs shall be provided with cord grips to prevent strain and damage to
conductors/wires at connection and entry points.
n) Junction boxes with terminals shall be supplied for branching and terminating
lighting cables when required for outdoor areas, 3 phase receptacles etc.
o) The junction boxes shall be dust and vermin proof and shall be fabricated from 1.2
mm to 2 mm CRCA sheet steel depending on the size of the junction box and shall
be complete with removable cover plate with gaskets, two earthing terminals each
with nut, bolt and washer. Boxes shall be additionally weather proof when specified.
p) The boxes shall have provision for wall, column, pole or structure mounting and
shall be provided with cable/conduit entry knock outs, terminal blocks, HRC fuses,
as indicated in the Project drawing.
q) The terminal blocks, with specified number of terminals, shall be mounted securely
on brackets welded to the back sheet of the box. The terminals shall be 650 V grade,
one piece construction complete with terminals, insulation barriers, galvanised nuts,
bolts and washers and provided with identification strips of PVC. The terminals shall
be made of copper alloy and shall be of box clamp type.
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
r) The boxes shall be hot dip galvanized /painted with one shop coat of red oxide zinc
chromate primer followed by a finishing coat of paint as specified.
1.4.16 DC Distribution Boards
DCDBs shall have two incomers and a bus coupler. Incomers and outgoing feeders of
DCDBs shall be MCB/MCCB modules. They shall be fixed type and floor mounted. Other
constructional features shall be similar to ACDB.
The feeder rating and quantity shall be as per requirement.
1.4.17 Control & Indication
The circuit breaker shall be wired up for local & remote operation. Each breaker cubicle
shall be equipped with following:
a) Remote selector switch with pistol grip handle and key interlock for breakers with
motor wound spring charging mechanism. In Remote position, the breaker can be
operated in service position with all interlock and protections. In switchgear
position, the breaker shall be operated from switchgear only in test position with
only protection (no interlock).
b) Two (2) heavy duty, oil-tight, push buttons for Trip & Close.
c) Circuit breaker shall be indicated electrically. The following indication colour shall be
used.
Breaker open - GREEN
Breaker closed - RED
Spring Charged - WHITE
Breaker Auto Trip- AMBER
d) However, any other indication shall be provided as per owner s requirement.
e) Lamps shall be LED type with resistance for voltage protection. Lamp and lens shall
be replaceable from the front.
f) For all MCCB feeders, trip indication lamp shall be provided on front of the
compartment.
g) For all starters, ON, OFF and trip indication lamps shall be provided on front of the
compartment.
1.4.18 Relays, Protection & Metering
a) The hardware design for protection and associated equipment shall use latest state–of–the-art technology and shall generally be integrated numerical/digital, modular
in nature. Where design is based on numerical technology, adequate self
testing/monitoring/diagnostic facilities shall be provided.
b) All numerical relays, auxiliary relays and devices shall be of types, proven for the
application; satisfying requirements specified elsewhere and shall be subject to
Purchaser's approval. Numerical Relays shall have appropriate setting ranges,
accuracy, resetting ratio, transient overreach and other characteristics to provide
required sensitivity to the satisfaction of the Owner.
c) All protective relays shall be in draw out or plug-in type / modular cases with proper
testing facilities. Necessary test plugs / test handles shall be supplied loose and shall
be included in supplier s scope of supply.
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
d) All AC operated relays shall be suitable for operation at 50 Hz. AC voltage operated
relays shall be suitable for 110 Volts VT secondary and current operated relays for 1
amp CT secondary. All relays and timers shall be rated for control supply voltage as
mentioned elsewhere under parameters and shall be capable of satisfactory
continuous operation between 80-120% of the rated voltage. Voltage operated
relays shall have adequate thermal capacity for continuous operation.
e) Energy meters shall be provided for incomer of 415V Switchgear and MCC and shall
able to communicate with SCADA. Accuracy class shall not be less than 1.0S.
f) Provision shall be made for easy isolation of trip circuits of each relay for the
purpose of testing and maintenance.
g) All protective relays and alarm relays shall be provided with one extra isolated pair
of contacts wired to terminals exclusively for future use.
h) The relay shall be designed to perform satisfactorily under highly noisy electrical
environment. Sufficient degree of high frequency disturbance immunity and impulse
voltage withstand capacity shall be built into electronic designs as stipulated in
relevant standards.
i) All protections shall be furnished complete with necessary auxiliary, supervisory,
lock out relays. Suitably separate sets of single phase auxiliary C.T with multiple taps
shall be provided with relay whenever required.
j) Visual and audible alarm annunciation shall be initiated in the event of operation of
protective/supervisory relay.
k) D.C supply shall be supervised by DC supervision relays.
l) Trip circuit shall be supervised by Trip circuit supervision.
m) Tripping shall be done through high speed lock out relays.
n) All meters/ instrument shall be flush mounted on front panel, at least 96mm2 size
with 900 linear scales and accuracy class of 2.0.
o) Interposing relays for ON/OFF command or any other command shall be as per
system requirement.
p) For alarm and Indication at SCADA end necessary contacts shall be provided at
switchgear end.
q) Metering and protection shall be as per below table
a) Incomers
Protections Metering
i Time graded short circuit protection Local Current (single phase) indication
and remote indication through
transducer.
ii Over current protection(51) Voltage Measurement for all three
phases and remote indication through
transducer.
iii Earth fault protection(51N) KW, Kwhr
b) Bus coupler
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
Protections Metering
i Over current protection(51) Local Current (single phase) indication.
ii IDMT Earth fault protection(51N)
c) Contactor controlled motor feeders [90kW and above motor only]
Protections Metering
i Time graded short circuit protection Local Current indication and remote
indication through transducer.
ii Over current protection
c) [Motor Feeders [of 132KW and above only)]
Protections Metering
Composite motor protection to
cover a minimum of protections
such as over current, short circuit,
earth fault, locked rotor, Negative
phase sequence, thermal overload
etc.
Local Current indication and remote
indication through transducer.
[Other feeders]
a) Bus PT / Line PT Modules
Protections Metering
Under voltage protection [Voltage – phase to phase,]
Fuse failure protection
b) Motor feeders (MPCB/MCCB with Contractors)
Protections Metering
Electronic Overload relay (with single
phase preventor), short circuit
protection (through fuse/MCCB/MPCB
as specified)
c) Incoming feeders for ACDB/DCDB
Protections Metering
Overload and Short circuit protection
(if MCCB)
[Voltage (single phase and, Phase
Current (1 Phase)] Local indication
only.
d) Outgoing feeders of ACDB/DCDB
Protections Metering
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
Short circuit protection (through
fuse/MCCB)
1.5 Tests
I) Type Test
For each type & rating of 415V Switchgear, the Bidder shall submit for Owner s approval
the reports of all the type tests as per relevant standards and carried out within last five
years from the date of bid opening. These reports should be for the tests conducted on
the switchgear similar to those proposed to be supplied under this contract and the
test(s) should have been conducted at an independent laboratory.
In case the Bidder is not able to submit report of the type test(s) conducted within last
five years from the date of bid opening, or in case the type test report(s) are not found
to be meeting the specification requirements, the Bidder shall conduct all such tests
under this contract free of cost to the Owner and submit the reports for approval.
II) Routine Test
All equipment shall be completely assembled, wired, adjusted and routine tested as per
relevant IS / IEC Standards at manufacturer's works in the presence of consultant
/purchaser or his representative.
The minimum tests shall be conducted are as follows:
a) Measurement of insulation resistance of Circuit Breaker in closed and open
positions.
b) Measurement of milli-volt drop across Circuit Breaker main contacts and other
joints.
c) Measurement of Circuit Breaker/Contactor operating time for close & open at
nominal voltage and 80% of rated voltage.
d) Measurement of resistance, IR value and drop-off/pick-up voltage of close and trip
coils.
e) Healthiness of limit switch contacts.
f) Spring charging motor functional checks.
g) Verification of phase sequence and checking of clearances of busbars between
phase to phase and phase to earth.
h) Measurement of milli-volt drop across busbar joints
i) Torque tightness test.
j) High voltage test on busbar.
k) Measurement of CT/PT polarity, ratio and knee point voltage.
l) Electrical and mechanical interlock checks.
m) Secondary injection of all protection relays by using service settings and simulation
of all protection functions.
n) Secondary injection of all metering circuits.
o) Functional tests to demonstrate the specified control and interlocks
III) Test Witness
[The tests shall be carried out in presence of the Owner’s representative, for which a
minimum 7 days notice shall be given by the Bidder. The Bidder shall obtain the Owner’s
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
approval for the type test procedure before conducting the type test. The test procedure
shall clearly specify the test set-up, instruments to be used, procedure, acceptance
norms, recording of different parameters, interval of recording, precautions to be taken
etc. for the type test(s) to be carried out.]
IV) Test Certificates:
Certified copies of all tests carried out at works and at site shall be furnished in requisite no.
of copies for approval of the Owner. The equipment shall be dispatched from works only
after receipt of Owner's written approval of shop test reports.
1.6 Drawing & Documents
Drawings, data & manuals for the motors shall be submitted as indicated below
a) [General Arrangement drawings and cross-section showing constructional features
& cable entry with bottom view with opening.
b) Bill of Materials.
c) Technical Data sheet and Catalogue.
d) Foundation drawing details with bottom view of switchgear.
e) Descriptive write-ups and literature for the main equipment offered including
relays, meters, etc.
f) Control Schematics & Wiring diagram.
g) Inspection and Test Plan (ITP).
h) Suggestive list of protective relays.
i) Transport/shipping dimensions and weights].
1.7 Ratings & Requirements
415V switchgears, MCC and DB shall comply with the particulars indicated in the
following tables.
Table- 2.0
S. No. DESCRIPTION UNIT DATA
1.0 General
1.1 Name of Manufacturer
1.2 Place & Country of manufacture
1.3 Specifications and Standards
2.0 Switchgear Details
2.1 Rated voltage, phases & frequency 415 Volts,
3 Phase, 4 wire
50 Hz.
2.2 System neutral earthing Solidly earthed
2.3 Voltage & frequency variation % +/-10%, -5%to +3% Hz.
2.4 Rated frequency Hz 50Hz
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
S. No. DESCRIPTION UNIT DATA
.4
2.4
One minute power frequency
Voltage
a) For power Circuits
b) For Control Circuits
a) 2.5kV
b) 1.5kV
2.5 Continuous current rating of busbars
under site reference ambient temp.
As Required
2.6 Reference ambient temperature 45C
2.7 Maximum temperature of bus bars
and droppers/connectors under site
conditions specified
900C for busbars having
non-silver plated joints
1050C for busbars having
silver plated joints
2.8 Short circuit current withstand for
busbars and droppers
a Short time kA (rms) 50 for LT Panel,
20 for LDB
b Dynamic Rating kA
(peak)
105
2.9 Whether busbars have been
insulated
Yes Required
2.10 Type of insulation [By Bidder]
2.11 Material of bus bar supports [By Bidder]
2.12 Switchgear designation
2.13 Bus bar material Al
2.14 Fully draw out (FD)/ Fixed (F) FD for Switchgear/MCC;
F for DBs.
2.15 Entry –Top (T)/Bottom (B) bottom for cables
2.16 Degree of protection IP 52
2.17 Colour finish shade Interior
Exterior
RAL 7032 (Siemens Gray)
2.18 Earthing bus Material GS
2.19 Minimum clearances in air of live
parts
mm As per standard
3.0 Starters
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
S. No. DESCRIPTION UNIT DATA
3.1 Type DOL DOL
3.2 Contactor rated duty AC3 for DOL
3.3 Single phasing preventer required. Yes / no Yes
3.4 Thermal overload relay reset Manual
/ Auto
Settable for either to
Manual or Auto
4.0 Circuit breakers
4.1 Maker s name [By bidder]
4.2 Voltage, frequency & no.of phases ,
poles
415 V, 50 Hz, 3 Ph, 4 Pole
4.3 Rated operating duty O-0.3sec-CO- 3min –CO
4.4 Circuit breakers type ACB
4.5 Short circuit withstand current for 1
sec. Duration
kA 50
4.6 Rated making current kAp 105
4.7 Rated current at site reference
ambient temp
A 0
C
[By bidder]
4.8 Type of operating mechanism Spring charged motor and
manual
4.9 Minimum no. of auxiliary
Contacts for purchaser s use
6 NO, 6 NC
4.10 Control voltage
a r Spring charging motor V AC/DC 230V AC
b For closing/tripping V AC/DC 110V DC
4.11 Limits of voltage for satisfactory
operation of the following devices as
a % of normal voltage
a Operating mechanism % As per IS
b Closing at normal voltage % As per IS
c Trip coil % As per IS
4.12 Power required for closing at normal
voltage
W [By bidder]
4.13 Power required for tripping at
normal voltage
W [By bidder]
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
S. No. DESCRIPTION UNIT DATA
4.14 Spring charging motor details:
a Rating kW [By bidder]
b Rated voltage V,
AC/DC
[By bidder]
c Spring charging Sec. [By bidder]
Electrical and mechanical anti-
pumping features been provided
Yes/No Required
5.0 MCCBs/MPCBs
5.1 Voltage, frequency, no. of phases &
poles
415 V, 50 Hz, 3phase & 3 P
for outgoing, 4P for
incoming and supply feeders
5.2 Rated operating duty As per IS
5.3 Rated breaking capacity
kA (rms) 50
5.4 Rated making current kA
(Peak)
105
5.5 On/off operation
5.6 Manual Yes/No
Yes
5.7 Over-load inverse time, short circuit
and earth fault
Yes/No Yes
5.8 Auxiliary contacts required Yes/No Yes
6.0 MCBs
6.1 Voltage, frequency, no. of phases &
poles
240 / 415 V, 50 Hz 3Phase &
4 Pole
6.2 Rated operating duty
6.3 Rated breaking capacity
kA (rms) 10 at 415V AC
6.4 Rated making current kA
(Peak)
17 at 415V AC
6.5 On/off operation
6.6 Manual Yes/No Yes
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
S. No. DESCRIPTION UNIT DATA
6.7 Over-load inverse time, Over
Current, short circuit and earth fault
Over Current and Short
Circuit only
6.8 Auxiliary contacts required Yes/No No
7.0 Contactors
7.1 Make [By Bidder]
7.2 Rated duty AC3/AC
4
AC3 for DOL
7.3 No of poles 3
7.4 Utilization category [By Bidder]
7.5 Rated voltage of auxiliary contacts V [By Bidder]
7.6 Rated voltage of coil V [By Bidder]
7.7 Rated breaking capacity Factor
of rated
current
[By Bidder]
7.8 Rated making capacity Factor
of rated
current
[By Bidder]
7.9 Limits of operation As per IS/IEC
a Supply voltage variation [By Bidder]
b Supply frequency variation for
closing
[By Bidder]
c Drop out voltage [By Bidder]
7.10 No of auxiliary contacts:
a Normally open
b Normally closed
8.0 Instrumentation transformers
8.1 Voltage Ratio [415/sqrt(3)/110/sqrt(3)]
8.2 CT Ratio Primary current/1A
8.3 Measuring CTs Cl - 1.0 instrument safety
factor 5.0
8.4 Protection CTs Cl 5P20
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
S. No. DESCRIPTION UNIT DATA
8.5 Measuring VTs (min)/phase Cl1.0
8.6 Protection VTs Cl 3P
9.0 Control transformers
9.1 Make [By Bidder]
9.2 Type Dry Type
9.3 Applicable standards As specified in the
specification
9.4 Ratio [415/sqrt(3)/110/sqrt(3)]
9.5 Class of insulation Class-B or Better
9.6 Rated output VA 50
10.0 Fuse (if applicable)
a Type
b Voltage rating
11.0 Instantaneous over current relay
11.1 Application (phase fault or earth
fault)
[By Bidder]
11.2 Make [By Bidder]
11.3 Type designation [By Bidder]
11.4 Setting range [By Bidder]
12.0 Inverse time and thermal
overcurrent relay
12.1 Application [By Bidder]
12.2 Make [By Bidder]
12.3 Type [By Bidder]
12.4 Current setting range [By Bidder]
12.5 Time setting range at 10 times the
current setting
Sec [By Bidder]
13.0 Under voltage relay
13.1 Make [By Bidder]
13.2 Type [By Bidder]
13.3 Voltage rating V [By Bidder]
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
S. No. DESCRIPTION UNIT DATA
13.4 Setting range V [By Bidder]
14.0 Auxiliary relays and timers
14.1 Make [By Bidder]
14.2 Type [By Bidder]
14.3 Coil voltage V [By Bidder]
15.0 Control/selector switch
15.1 Make [By Bidder]
15.2 Type designation [By Bidder]
16.0 Meters
16.1 Applicable Standards As specified in the specification
16.2 Accuracy Class Class 1.0 or
Better
16.3 Make [By Bidder]
16.4 Type Multi function
with RS 485 connectivity
17.0 Voltmeter
17.1 Make *[By Bidder]
17.2 Type Moving coil
17.3 Applicable standards As specified in the specification
17.4 Accuracy class Class 1.0
18.0 Ammeter
18.1 Make As specified in the specification
18.2 Type Moving coil
18.3 Applicable standards As specified in the specification
18.4 Accuracy class Class 1.0
19.0 Indicating lamps
19.1 Make As specified in the specification
19.2 Type Clustered Led
Tender Specification for 415V SWITCHGEAR, APFC PANEL, MCC AND DB
ABD, Ranchi Smart City
S. No. DESCRIPTION UNIT DATA
19.3 Voltage V As specified in the
specification.
19.4 Wattage of lamp W As specified in the
specification.
20.0 Push buttons
20.1 Make As specified in the
specification.
20.2 Type designation As specified in the
specification.
20.3 Contact rating A As specified in the
specification.
21.0 Space heater
21.1 Make As specified in the
specification.
21.2 Type As specified in the
specification.
21.3 Rated voltage V As specified in the
specification.
22.0 Wiring and terminal blocks
22.1 Voltage grade 1.1 kV
22.2 Insulation [By Bidder]
22.3 Minimum size of conductor for:
A Power wiring Sq.mm 2.5 for CT & PT
1.5 for Others
B Control wiring Sq.mm 1.5 for Others
22.4 Type of terminal blocks:
I) For Withdrawable Type Sliding type
II) For Fixed Type Stud & nut type
22.5 Minimum current rating of terminal
blocks
A 10
TECHNICAL SPECIFICATION
FOR SMART GRID SYSTEM
2.0 SMART GRID SYSTEM ............................................................................................................... 6
2.1 GENERAL ...................................................................................................................................................... 6
2.3 SYSTEM REQUIREMENTS .............................................................................................................................. 8
2.4.1. Head End System (HES) ......................................................................................................................... 10
2.4.2. Meter Data Management System (MDMS) .......................................................................................... 11
2.4.3. Communication Feature ....................................................................................................................... 13
2.5 SCADA ARCHITECTURE & ELEMENTS ......................................................................................................... 14
2.5.1. Communication protocol ........................................................................................................................ 1
2.5.2. Design Requirements of SCADA System ................................................................................................. 1
2.5.3. Data Acquisition & Monitoring System (DAMS) ...................................................................................... 5
2.5.4. Data Processing ....................................................................................................................................... 6
2.5.5. Analog Data Processing ........................................................................................................................... 7
2.5.6. Digital Input Data processing .................................................................................................................. 9
2.5.9. Supervisory Control ............................................................................................................................... 14
2.5.10. Digital Status Control ............................................................................................................................ 15
2.5.13. Tap Changing Transformers .................................................................................................................. 16
2.5.14. Set Point Control ................................................................................................................................... 17
2.5.15. Auto Execution sequence/ Group Control ............................................................................................ 17
2.5.16. Control Inhibit Tag (Tagging) ................................................................................................................. 18
2.5.17. Information Storage and Retrieval ........................................................................................................ 18
2.5.18. Data Exchange with Customer Care System ......................................................................................... 23
2.5.19. Data Exchange with GIS system ............................................................................................................ 23
2.5.20. Historical Information ........................................................................................................................... 25
2.5.21. System Message Log Storage and Retrieval .......................................................................................... 25
2.5.22. Auxiliary Power System (APS) ............................................................................................................... 26
2.6 ADVANCED DISTRIBUTION MANAGEMENT SYSTEM (ADMS) .................................................................... 26
2.6.6. Network Model ..................................................................................................................................... 28
2.6.8. State Estimation .................................................................................................................................... 33
2.8.5. Time and Frequency Facility .................................................................................................................. 61
2.9.2. System Design ....................................................................................................................................... 63
2.9.5. Communication Interfaces .................................................................................................................... 68
2.9.14. Local Configuration & Maintenance Interface ...................................................................................... 73
2.9.15. Local Data Monitoring System (LDMS) Interface .................................................................................. 73
2.9.16. Communication interface between RTU & MFTs .................................................................................. 73
2.9.17. Master Station Communication Protocol.............................................................................................. 74
2.9.18. Scan Groups .......................................................................................................................................... 74
2.9.19. RTU Communication Protocol ............................................................................................................... 75
2.10.3. Communication ports............................................................................................................................ 82
2.10.4. Master Station Communication Protocol.............................................................................................. 82
2.10.5. Communication Protocol between FRTU & MFTs ................................................................................. 82
2.10.9. Communication ..................................................................................................................................... 84
2.10.11. Access control ....................................................................................................................................... 84
2.10.12. Management of Security passwords ..................................................................................................... 85
2.10.13. User Authentication .............................................................................................................................. 85
2.10.14. Central management of user account ................................................................................................... 85
2.10.18. Status input (32 DI in IO module) .......................................................................................................... 86
2.10.19. Sequence of Events (SOE) feature ......................................................................................................... 86
2.10.20. Control Outputs (16 DO in IO module).................................................................................................. 86
2.10.21. Analog Inputs (4AI capability in IO module) .......................................................................................... 87
2.10.23. Time facility ........................................................................................................................................... 88
2.10.25. Power Supply ........................................................................................................................................ 89
2.11.1. DC Transducer ....................................................................................................................................... 91
2.11.2. Transformer Tap Position Transducer ................................................................................................... 91
2.11.4. Design & Performance Requirements of Transducers .......................................................................... 92
2.12 USER INTERFACES....................................................................................................................................... 93
2.12.1. System Users ......................................................................................................................................... 93
2.12.2. Function and Data Access Security ....................................................................................................... 94
2.12.3. Windows Environment .......................................................................................................................... 95
2.13.2. Design and Coding Standards for smart grid integrated applications................................................. 113
2.13.3. Operating System ................................................................................................................................ 113
2.13.4. Time and Calendar Maintenance ........................................................................................................ 113
2.13.9. Design and Performance Requirements of Software .......................................................................... 124
2.14 CONFIGURATION AND SYSTEM AVAILABILITY ......................................................................................... 126
2.14.1. General ................................................................................................................................................ 126
2.14.2. System Redundancy ............................................................................................................................ 126
2.17 BILL OF QUANTITY .................................................................................................................................... 136
Tender Specification for SMART GRID System
ABD, Ranchi Smart City
2.0 SMART GRID SYSTEM
2.1 GENERAL
This specification is intended to cover the [design, Engineering, manufacture, assembly, testing at
manufacturer's works, supply in properly packed condition for transport to site, Erection, site testing and
commissioning] of Smart Grid System which includes-
i. Advanced metering infrastructure (AMI), with two way communication and Meter
Data Management Systems
ii. Distribution Automation and Substation Automation Systems, Supervisory Control
and Data Acquisition Systems (SCADA)
iii. Advanced Distribution Management Systems (ADMS)
iv. Automation of the substations with modern switchgear and numerical relays
v. Customer portal
vi. Enterprise IT network covering all substations and field offices with reliable
communication systems
vii. Electronic billing systems and customer care systems
viii. Enterprise Resource Planning (ERP)/Asset Management Systems,
ix. Integration of all smart grid systems.
The System should be capable to integrate following system if required in future-
i. Outage management system (OMS)
ii. Demand response
iii. Renewable integration.
The system shall be complete in all respect including all accessories required for efficient and trouble-
free operation of Ranchi Smart City, Jharkhand.
Following Automation is proposed for controlling, monitoring and metering of complete Electrical
System within ABD from a Control Centre (CC) located at Main Receiving Sub Station (MRSS).
Tender Specification for SMART GRID System
ABD, Ranchi Smart City
i. 4 nos. of 33/11kV Distribution Substation Automation through RTUs & Intelligent Electronic
Devices (IEDs) like Numerical relays, Bay Control Units (BCU), Tap Changer Controller (TCC) etc
and SCADA system compatible for communication with IEC 60870-5-104.
ii. 33 & 11kV Distribution Ring Network automation through IEDs, Fault Passage Indicators (FPI),
Self-Healing System and FRTUs
iii. 415V Switchgear automation including Utilities through smart panels like Intelligent MCCs.
iv. Local field control of breaker and isolator will be done only during maintenance and testing.
Parameters to be monitored and control of 33/11kV substation, including Power & distribution
transformers, 33 & 11 kV switchgears, RMUs, CSS placed at different locations-
a) Incoming Phase Voltage, Phase Current, Active Power, reactive Power, Power Factor.
b) Outgoing Phase Voltages, Phase Currents, Neutral Float condition, Active Power, reactive Power,
Power factor, efficiency.
c) FPI (Fault Passage Indicator), Oil temperature, Levels if any, Bus bar palm temperature.
d) Controlling of motorized circuit breaker, etc.
2.2 CODES & STANDARDS
All equipment and materials shall be designed, manufactured and tested in accordance with the latest
applicable Indian Standards (IS) / IEC as given below except where modified and/or supplemented by
this specification.
S.No Activity Standards
1. CIM Standard IEC 61970
2. CIM Standard for Distribution IEC 61968
3. Communication Network for Substation Automation IEC 61850
4. ICCP IEC 60870-6
5. Cyber Security Standard IEC 62351-1-7
6.
Electricity Metering; data exchange for metering, tariff and
load control
IEC 62056
7. Grid Connectivity IEEE 1547 MNRE Guidelines
8. International Telecommunications Union -
Tender Specification for SMART GRID System
ABD, Ranchi Smart City
Equipment and material conforming to any other standard, which ensures equal or better quality, may
be accepted. In such case, copies of the English version of the standard adopted shall be submitted
along with the bid.
The electrical installation shall meet the requirements of Indian Electricity Rules as amended up to date
and relevant IS Code of Practice. In addition, other rules and regulations applicable to the work shall be
followed.
2.3 SYSTEM REQUIREMENTS
Smart Grid system shall include the following:
(i) Connectivity with the State Load Dispatch Centre (SLDC) for the exchange of information
regarding Load Management & Forecast, AT&C losses, Outages etc. for ABD. The system
shall be compatible with the existing IT/ ERP systems of the Utility Supply Company.
(ii) The proposed system shall be capable of Data acquisition, validation, processing, and data
archiving /storage of the electrical network within ABD in order to control and manage the
Load including forecasting and outages, billing, and interface with end consumers through
various portals.
9. National Electricity Manufacturers Association (NEMA). -
10. The institute of Electrical and Electronic Engineers (IEEE). -
11. Instrument Society of America (ISA). -
12. American National Standards Institute (ANSI). -
1.1 General ..................................................................................................................................................... 3
1.3 System Description ................................................................................................................................... 4
1.4 Applicable Codes And Standards ............................................................................................................... 4
1.5 Specific Requirements of Compact Substation .......................................................................................... 4
1.6 System Particulars ..................................................................................................................................... 7
1.7 Installation of CSS ..................................................................................................................................... 8
1.8 Packing – Transport And Installation ......................................................................................................... 9
1.10 Drawings And Data.................................................................................................................................... 9
Technical Specification for COMPACT SUBSTATION
ABD, Ranchi Smart City
1. COMPACT SUBSTATION
1.1 General
This specification is intended to cover the [design, Engineering, manufacture, assembly, testing
at manufacturer's works, supply in properly packed condition for transport to site, Erection, site
testing and commissioning] of COMPACT SUBSTATION
The system shall be complete in all respect including all accessories required for efficient and
trouble-free operation of Ranchi Smart City, Jharkhand
1.2 Scope
(i) All scope for Supply, Installation, Testing and Commissioning (SITC) of the equipment and
systems as specified in this contract/ specification shall be strictly as per specification, rules and
regulations; and, not limited to this specifications and guidelines.
(ii) Each CSS shall typically consist of the following parts:-
a) Metallic Enclosure with ventilation and rain/ dust protection as appropriate.
b) 11kV Ring Main Unit (RMU) (630A, 2 nos. Load break switches as incomers + 1no. self
powered VCB as outgoing) with fault passage indicator.
c) Smart meter
d) 11kV / 0.433kV dry type transformer of respective rating along with required
accessories.
e) LT switchgear & APFC
f) Necessary arrangement required for Eight (8) Hr backup to take care of the DC load
requirements within the CSS.
g) FRTU (Field remote terminal unit), should be part of enclosure.
(iii) All the above components of each CSS shall conform to latest relevant standards, codes and
requirements.
(iv) Civil works for the preparation of equipment foundation, cable trench, earth pits electrodes,
earth grid around CSS and chain link fencing with gate for each CSS is included in the scope of
this specification. GA drawings for same shall be submitted by the Contractor.
(v) Smart meter along with the mounting enclosure and all accessories like CTs, terminals, etc.,
shall be as per distribution company requirement & specifications and should be approved
from Distribution Company.
(vi) All SAFETY considerations in design and manufacturing for safe operation & maintenance by
Employer personnel and safe practices during installation at site shall be in the scope of the
Contractor. Cost towards accomplishing the same shall be included in the BID price and no
extra claim shall be entertained later.
Technical Specification for COMPACT SUBSTATION
ABD, Ranchi Smart City
(vii) Equipments furnished shall be complete in every respect with all mountings, fittings, fixtures,
and standard accessories normally provided with such equipment and / or needed for
erection, completion and safe operation of the equipment as required by applicable codes
though they may not have been specifically detailed in the Technical Specification unless
included in the list of exclusions. Materials and component not specifically stated in the
specification but which are necessary for commissioning and satisfactory operation unless
specifically excluded shall be deemed to be included in the scope of specification and shall be
supplied without any extra cost. All similar standard components/ parts of similar standard
equipment provided shall be inter-changeable with one another.
(viii) The Contractor shall be responsible for the selection and design of appropriate equipment to
provide the best co-ordinated performance of the entire system. The design of various
components, sub-assemblies and assemblies shall be so done that it facilitates easy field
assembly and maintenance.
1.3 System Description
(i) 4 nos. of 11kV/0.433kV 250kVA CSS will be required to feed the LT load of Common services like
Open space lighting, Street Lighting & other loads etc.
1.4 Applicable Codes And Standards
(i) The design, manufacture and performance of equipment shall comply with latest applicable
10.2 Sampling for FAT ............................................................................................................. 8
10.3 Site Acceptance Tests ..................................................................................................... 9
TECHNICAL SPECIFICATION FOR HDPE CONDUIT FOR POWER CABLE
ABD, Ranchi Smart City
HDPE PIPE CONDUIT FOR POWER CABLES
1.0 GENERAL
This specification is intended to cover the [design, engineering, manufacture, assembly, testing at manufacturer's works, supply in properly packed condition for transport to site, Erection, site testing and commissioning] of High-Density polyethylene primarily intended for buried for laying of MV (33kV & 11kV) and LV underground Power cables up to 400 mm2 as per NEMA TC-7 or any equivalent Indian standard with latest amendment. The expected service life of HDPE pipe and accessories shall not be less than 50 years.
2.0 DETAIL REQUIREMENTS OF HDPE PIPE
The HDPE pipe shall be of grade quality PE100 and the pressure rating shall be PN10.
The HDPE pipe of standard make shall have the outer diameter as follows.
S. No. Type of Cable Outer Diameter of Pipe in mm
1 33 kV/11 kV(MV) 200
2 LV cable 200
3 Service Cable 200
TECHNICAL SPECIFICATION FOR HDPE CONDUIT FOR POWER CABLE
ABD, Ranchi Smart City
3.0 CODES AND STANDARDS
All equipment and materials shall be designed, manufactured and tested in accordance with the latest applicable Indian Standards (IS) / IEC/ASTM as given below except where modified or supplemented by this specification.
The PLB (Permeant Lubricant) HDPE pipe shall conform to the following standard and the technical specifications described below.
S.N Standard Number Characteristics Requirement
1 ISO 1183 Density of Raw Material
≥ 930 Kg/m³
2 ISO 1133 Melt Flow Rate The melt flow rate of the duct should be 0.2 to 1.1 Grams/10 Minutes @5kg.
3 ISO 6259 - 1 & 3 Tensile Strength At Yield
Min 18 N/mm²
4 ASTM D 1693 Environmental Stress Crack Resistance
There should be no crack or split when tested with 10% IGEPAL - CO – 630 solution at 50 ± 1º C for 96 hours.
5 IS 4984-1995 Ovality Maximum 2% of outer diameter.
6 IS 4984-1995 Reversion 3.00% Max
7 ISO 6259 - 1 & 3 Elongation Min 350%
8 ISO 4427 /
ISO 18553
Colour Pigment Dispersion (Outer Layer)
≤ Rating A3
9 ASTM D5630 Ash Content of Outer Layer of the Duct
≤ 0.3%
10 IS 12235 (Part 9) Impact Strength There should be no crack / split when 10 Kg load dropped from 1.50 Meter height after conditioning at 0º C for 1 hour.
11 ASTM F 2160 Toe- in
Outside diameter at cut end of the conduit shall not be more than 1.5% smaller than outside diameter that measured at 300mm away from the cut end of the conduit.
12 ASTM F 2160
Friction reduction
Lubrication materials shall be compatible with the conduit & any cable jacketing.
TECHNICAL SPECIFICATION FOR HDPE CONDUIT FOR POWER CABLE
ABD, Ranchi Smart City
Equipment and material conforming to any other standard, which ensures equal or better quality, may be accepted subject to approval of the Owner. In such case, copies of the English version of the standards adopted shall have to be submitted along with the bid.
The electrical installation shall meet the requirements of Indian Electricity Rules as amended upto date and relevant IS Codes of Practice. In addition, other rules and regulations applicable to the work shall be followed.
4.0 MATERIAL:
The raw material used for the HDPE pipe shall meet the following requirements
i. the anti-oxidant establishers, color master batch and other additive used
shall be physiologically harmless and shall be used only to minimum extent
necessary to meet the specification.
ii. Usage of any additives used separately or together should not impair the
long-term physical and chemical properties of the HDPE pipe.
iii. Suitable Ultra-Violet stabilizers may be used for manufacture of the HDPE
pipe to protect against UV degradation when stored in open for a minimum
period of 8 months.
iv. In case of HDPE pipe of three concentric layer construction, the friction
reducing, polymeric material to be used as the inner layer lubrication
material shall be integral with HDPE layer.
4.1 Tests on Material of HDPE pipe:
4.1.1 The base HDPE resin material shall be subjected to following tests and shall satisfy
i. Melt flow Index: ISO 1133
ii. Density: ISO 1183
4.2 Dimension of Pipe:
Duct shall have Nominal Diameter of 200mm and shall have a dimensional ratio of 13.5 (SDR)
4.2.1 Dimensions of HDPE Duct:
Sl. No Description 200 DIA
1 Outer Diameter of Pipe (mm) 200 + 1.50
2 Wall Thickness (mm) 14.80 to 16.50
3 Ovality Max 4
4.2.2 Pipe Length shall be 6 or 12 meters, length of supply preferred to be 12 mtrs.
4.2.3 HDPE Ducts should be sourced from the manufacturer with ISO 9001 accredited manufacturing facility.
TECHNICAL SPECIFICATION FOR HDPE CONDUIT FOR POWER CABLE
ABD, Ranchi Smart City
5.0 ACCESSORIES:
5.1.1 The following accessories are required for jointing the pipe and shall be supplied along with the pipe. The manufactures shall provide complete design details, procedure for method of installation and type of the material used for the accessories.
5.1.2 Plastic coupler: The coupler shall be used to join two HDPE pipes. The coupling shall be able to provide a durable water tight joint between two pipes without deteriorating the strength of the pipes. The strength of coupler shall match the primary strength of the HDPE pipe. It should either snap fit or Split type. The jointing shall meet the air pressure test of 2 kg/cm2 for a minimum period of 2 hours without any leakage.
6.0 WORKMANSHIP:
6.1.1 The pipe shall be free of blisters, shrink holes, break and other defects. The HDPE pipe ends shall be cut as square as possible to longitudinal aspects. The external HDPE pipe surfaces shall be smooth. The color of outer surface should be Red uniform throughout.
7.0 MARKING:
7.1.1 Each straight length of pipe shall be clearly marked hot embossed on white base or ink jet in black on straight length of the pipe at every meter of pipe with the following information:
a) Employer’s name,
b) Manufacturer’s name/Trade-mark,
c) Designation of pipe,
d) Lot number/Batch number,
8.0 TESTS ON FINISHED HDPE PIPE:
8.1.1 Visual Inspection: The external surfaces of the pipes shall be smooth and inner surface of the pipe shall be clean and free from grooving and other defects. The pipe shall be cleanly cut and shall be square with axis of the pipes. Slight shallow longitudinal grooves or irregularities in the wall thickness shall be permissible, if the wall thickness remains within the permissible limits.
8.1.2 Dimensions: The wall thickness and diameter of the pipe, shall be measured by a dial Vernier or ball ended micrometer. The diameter shall be measured with circometer and shall conform to the figures given in the clause 1.4.1.
8.1.3 Reversion Test: This test shall be carried out as per IS: 4984. The dimension of inner layer or outer layer shall not change by more than 3% in the longitudinal direction when a sample pipe placed (sample length 200mm approx..) horizontally in an air-oven at 110+/-2o C for 60 minutes and cooled to the room temperature.
8.1.4 Tensile Strength at yield and Elongation at break Test: The tensile strength and elongation of the HDPE pipe shall be carried out as per ISO: 6259 1& 3.The tensile strength for finished material shall be minimum 18 N/mm2 and elongation at break shall be 350%.
8.1.5 Environmental Stress Crack Test: The test shall be conducted as per ASTM D 1693
TECHNICAL SPECIFICATION FOR HDPE CONDUIT FOR POWER CABLE
ABD, Ranchi Smart City
with the specimen prepared from HDPE pipe after making compression moulding sheet. The specimen shall be immersed in 10% IGPAL (CO 630) Solution at 50± 1o C for 96 hrs. There shall be no crack or split.
8.1.6 Impact Strength Test: The test shall be carried out as per IS:12235 (Part 9). A sample HDPE pipe 150mm in length shall be conditioned at 0◦C for one hour and placed on a heavy rigid block whose faces are at angle of 120o. A striker with a total weight of 10kg shall be allowed to fall freely in a suitable vertical guides through a height of 1.5m. The HDPE pipe shall not crack or split.
8.1.7 Crush Resistance: The test shall be in a sample of 200± 2 mm length of HDPE pipe which shall be subjected to crush load as specified below with compression speed 12.5 mm per minute. The deflection with crush load on period shall not exceed 5%.
i. 200 mm: 1500 N Minimum
8.1.8 Ovality test: The ovality is the difference between maximum outside diameter and the minimum outside diameter of the HDPE pipe at same cross section of the duct at 300mm away from the cut end. The same shall be measured as per IS-4984 as described above.
8.1.9 Raw Material: HDPE Virgin material shall be used. No other reworked or recycled material shall be used
9.0 PACKING AND CONDITION OF DELIVERY:
9.1.1 All materials furnished and all work performed shall be inspected and tested. Deliverables shall not be shipped until all required inspections and tests have been completed, and all deficiencies have been corrected to comply with this Specification and approved for shipment by the Employer.
9.1.2 Except where otherwise specified, the Contractor shall furnish all manpower and materials for tests, including testing facilities, power and instrumentation, and replacement of damaged parts. The costs shall be borne by the Contractor and shall be deemed to be included in the contract price.
9.1.3 The entire cost of testing for factory & site acceptance, routine tests, production tests and other test during manufacture & site activities specified herein including the expenses of Inspector/Employer’s representative shall be treated as included in the quoted unit price of materials.
9.1.4 Acceptance or waiver of tests will not relieve the Contractor from the responsibility to furnish material in accordance with the specifications.
9.1.5 All tests shall be witnessed by the Employer and/or its authorized representative (hereinafter referred to as the Employer) unless the Employer authorizes testing to proceed without witness. The Employer representative shall sign the test form indicating approval of successful tests.
9.1.6 Should any inspections or tests indicate that specific item does not meet Specification requirements, the appropriate items shall be replaced, upgraded, or added by the Contractor as necessary to correct the noted deficiencies at no cost to the Employer. After correction of a deficiency, all necessary retests shall be performed to verify the effectiveness of the corrective action.
9.1.7 The Employer reserves the right to require the Contractor to perform, at the Employer’s
TECHNICAL SPECIFICATION FOR HDPE CONDUIT FOR POWER CABLE
ABD, Ranchi Smart City
expense, any other reasonable test(s) at the Contractor’s premises, on site, or elsewhere in addition to the specified type. Acceptance, Routine or Manufacturing tests to assure the Employer of specification compliance.
9.1.8 The Employer also reserves the right to require any retesting of previously approved tests at the Employer’s expenses. However, if the retest(s) reveal non-compliance to the specification, the Contractor shall bear the expenses for the retesting and remedial action at no cost to the employer.
10.0 Factory Acceptance Test:
10.1.1 Factory acceptance tests shall be conducted on randomly selected final assemblies of all equipment to be supplied. Visual inspection shall be carried out on 100% basis for all the equipment/items offered. Factory acceptance testing shall be carried out on HDPE and accessories.
10.1.2 Material shall not be dispatched to the Employer until required factory tests are completed satisfactory all variances are resolved, full test documentation has been delivered to the Employer, and the Employer has issued Material Inspection & Clearance Certificate (MICC). Successful completion of the factory tests and the Employer approval to dispatch shall in no way constitute final acceptance of the system or any portion thereof. These tests shall be carried out in the presence of the Employer’s authorized representatives.
10.1.3 Factory acceptance tests shall not proceed without the prior delivery to and approval of all test documentation by the Employer.
10.1.4 The factory acceptance test shall demonstrate the technical characteristics of the equipment in relation to this specifications and approved drawings and documents. The factory acceptance test for items shall be proposed by the Contractor in accordance with technical specifications and Contractor’s (including Sub-Contractor’s/supplier’s) standard FAT testing program. For Test equipment, FAT tests shall include supply of proper calibration certificates, demonstration of satisfactory performance, evidence of correct equipment configuration and manufacturer’s final inspection certificate/report.
10.2 Sampling for FAT
10.2.1 From each batch HDPE pipe presented by the Contractor for Factory acceptance testing, the Employer shall select random sample (s). For HDPE pipes, following sampling plans shall be followed.
10.2.2 Sampling plan for Visual inspection and dimensional test
Scale of sampling for Visual inspection and dimensional test shall be as per below table:
No of Pipes in the Lot
Sample No A
Sample Size
Cumulative Sample Size
Acceptance No
Rejection No
(1) (2) (3) (4) (5) (6)
Upto 150 First 13 13 0 2
TECHNICAL SPECIFICATION FOR HDPE CONDUIT FOR POWER CABLE
ABD, Ranchi Smart City
Second 13 26 1 2
151 to 280 First 20 20 0 3
Second 20 40 3 4
281 to 500 First 32 32 1 4
Second 32 64 4 5
501 to 1200 First 50 50 2 5
Second 50 100 6 7
1201 to 3500 First 80 80 3 7
Second 80 160 8 9
3501 to above First 125 125 5 9
Second 125 250 12 13
10.2.3 The number of pipes given for the first sample in col 3 of above Table shall be examined for dimensional and visual requirements given in clause 8.1.1 & 8.1.2. A pipe failing to satisfy any of these requirements shall be considered as defective. The lot shall be deemed to have satisfied these requirements, if the number of detectives found in the first sample are less than or equal to the corresponding acceptance number given in col 5 of above Table. The lot shall be deemed not to have met these requirements if the number of detectives found in the first sample is greater than or equal to the corresponding rejection numbers given in column 6 of above Table.
10.2.4 If, however, the number of detectives found in the first sample lies between the corresponding acceptance and rejection numbers given in col 5 and 6 of above Table, the second sample of the size given in col 3 of above Table shall be taken and examined for these requirements. The lot shall be considered to have satisfied these, requirements, if the number of detectives found in the cumulative sample is less than or equal to the corresponding acceptance number given in col 5 of above Table; otherwise not.
10.2.5 Sampling Plan for performance test
The lot having satisfied dimensional and visual requirements shall be tested for other requirements with the sample size selected as per below Table from the lot. The lot shall be considered to have met the requirements of these tests, if none of samples tested fails.
No. of pips in the lot Sample size
Up to 150
151 to 1200
1201 and 3500
3501 and above
3
5
8
12
10.2.6 Since FAT testing provides a measure of assurance that the Quality Control objectives are being met during all phases of production, the Employer reserves the right to require the Contractor to investigate and report on the cause of FAT failures and to suspend further testing/approvals until such a report is made and remedial actions taken, as applicable.
10.3 Site Acceptance Tests
TECHNICAL SPECIFICATION FOR HDPE CONDUIT FOR POWER CABLE
ABD, Ranchi Smart City
10.3.1 Randoms checks somewhere in the middle of the pipe, by cutting the duct, will be made at site to ensure that ducts supplied are of correct dimension and thickness and there is no compromise on thickness in intermediate length, for saving in materials cost.
10.3.2 100% Duct pipe being supplied would be measured length to cross check the length of the duct pipe.
10.3.3 To keep a check on the use of filler material, ash contents would be determined on randomly selected samples as per ASTM D 1603 method and the value of ash content, thus determined, shall not exceed 0.3% (outer coloured layer).
10.3.4 UV Stabilise Content: UV Stabiliser content of finished duct shall not be less than 0.15%
10.3.5 Third party inspection on above, in addition to inspection at factory, would be carried out by independent agencies. on randomly picked up samples from field for testing of relevant parameters, thereby ensuring right quality of ducts. Failure of samples to pass any of the prescribed tests/parameters would result in immediate invoking of PBG/Blacklisting of the Vendor.