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PAGE No.: 1 OF 39
L&T-VALDEL ENGINEERING LTD
19 PRIMROSE ROAD BANGALORE-560025
INDIA
PROJECT : MHS RE-DEVELOPMENT PROJECT PHASE II
CLIENT/OWNER : ONGC
CONTRACT No. : COWGD725
DOCUMENT No. : COWGD725-75-GEN-301
DOCUMENT TITLE : ELECTRICAL DESIGN BASIS
LTV L&T-OGSP ONGC OD ONGC OW
LARSEN AND TOUBRO LIMITED OIL AND NATURAL GAS
OIL & GAS SPECIAL PROJECTS CORPORATION LIMITED
0 15..04.08 APPROVED FOR DESIGN KV NKS NKS MK
C1 17.03.08 ISSUED FOR CLIENTS COMMENTS KV NKS NKS MK
REV. DATE REVISION DESCRIPTION PREPD. CHKD. APPD. P.M.
LTV5001-1/COWGD725
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PAGE No. 2L&T-VALDEL ENGINEERING
LTDREVISION STATUS SHEET
CONTRACT No. COWGD725
DOCUMENT No.: COWGD725-75-GEN-301 REV. 0 DATE 15.04.08
SIGN. :DOCUMENT TITLE: ELECTRICAL DESIGN BASIS
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NOTE: IF REVISION REQUIRES ADDITIONAL PAGES TO BE INSERTED IN BETWEEN THE DOCUMENT, THE NUMBER OF THE PAGE ATINSERTION SHALL BE NUMBERED WITH DECIMAL (e.g. INSERTION BETWEEN PAGE 10 AND 11 SHALL BE NUMBERED AS 10.1, 10.2 ........)
LTV5046-1/0
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TABLE OF CONTENTS
1.0 INTRODUCTION..................................................................... ............................................................... .........4
2.0 REFERENCES ...................................................................... ................................................................... .........4
3.0 CODES, STANDARDS AND ABBREVIATION.................................................................... .......................5
4.0 GENERAL REQUIREMENTS........................................................................................................................7
5.0 ELECTRICAL SYSTEM DESIGN.................................................................................................................9
6.0 POWER SYSTEM...........................................................................................................................................15
7.0 SPECIFIC REQUIREMENTS FOR EQUIPMENT AND ASSOCIATED COMPONENTS..................17
8.0 ELECTRICAL EQUIPMENT/PRODUCT/MATERIAL SELECTION PHILOSOPHY........................27
9.0 ELECTRICAL EQUIPMENT CALCULATIONS.................................................................. ....................28
10.0 REVIEW AND APPROVAL..........................................................................................................................28
11.0 TAGGING AND NAMEPLATES ................................................................. ................................................ 29
12.0 ELECTRICAL EQUIPMENT INSPECTION & TESTING PHILOSOPHY........................................... 29
13.0 ELECTRICAL EQUIPMENT SPARES PHILOSOPHY ................................................................... ........30
14.0 TRANSPORT AND SHIPMENT ............................................................... ................................................... 30
15.0 WARRANTY...................................................................................................................................................30
16.0 DOCUMENTATION.............................................................. ................................................................ ........31
17.0 MODIFICATIONS ............................................................. ..................................................................... .......33
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1.0 INTRODUCTION
Oil and Natural Gas Corporation Limited, is engaged in exploration & exploitation of
Mumbai High Field located about 165 km. West-North-West of Mumbai located in the
Arabian Sea on the continental shelf of Western India. The field is well developed, with an
extensive infrastructure of wellhead platforms, process platforms and pipelines.
Under this project, ONGC Ltd plans to add 3 nos. unmanned platforms along with
associated pipelines and modification works at SQ well platform and BHS, ICP and SH
process platforms. The works include installation of 3 nos. well platforms namely RS-15,
RS-16 & RS-17. In addition, the associated works include laying of sub-sea pipelines,
sub-sea cables, modifications on existing platforms and miscellaneous works.
2.0 REFERENCES
This document is prepared based on the following provided along with the bid package.
Background and general (Basic Bid Work) MHS Re-Development (Phase-II) Project,
Rev.0
Description of work (Basic Bid work) for MHS Re-Development (Phase-II) Project (RS-15, RS-16 & RS-17), Rev.1, Volume- II
Design Criteria for Well Platform (Submarine Cable), Rev.0
Addendum I
Addendum to Volume -1
Annexure X of Instrumentation design criteria Vol-II Rev 2
COMPANY Reply to Bidders Queries
Further, these documents describe the brief scope of work and design criteria to be followed
for the electrical works for the MHS Re-development Project Phase-II covered in the bid
package. The electrical work shall consist of design, detailed engineering, supply, erection,
testing and commissioning of the complete electrical facilities for the project as per theDesign Criteria, Equipment Specifications, Data sheets, Drawings and Standards included in
the bid package.
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3.0 CODES, STANDARDS AND ABBREVIATION
Design of the electrical systems shall be based upon the requirements of the latest versions
of all applicable International Standards, Codes, Regulations and Code of Practice being
followed by the Industries world-wide. Some of them are listed below
CODE DESCRIPTION
API RP 500 (1997)
Recommended Practice for Classification of Locations for
Electrical Installations at Petroleum Facilities Classified as ClassI, Division I and Division 2
API RP 14C (2001)
Recommended Practice for Analysis, Design, Installation, and
Testing of Basic Surface Safety Systems for Offshore Production
Platforms
API RP 14F (1999)Recommended Practice for Design and Installation of Electrical
Systems for Offshore Production Platforms
IEC 60079-1(2005)Electrical apparatus for explosive gas atmospheres.
IALA (1984) International Association of Light House Authorities
IEC-60228 (2004) Conductors of insulated cables.
IEC 60332-1-2
(2004)
Tests on electric and optical fibre cables under fire conditions -
Part 1-2: Test for vertical flame propagation for a single insulated
wire or cable - Procedure for 1 kW pre-mixed flame.
IEC 60332-3
Category A (2000)
Tests on cables under fire condition-Part3: Tests for Vertical flame
spread of vertically mounted bunched wire of cables Category
A.
IEC 60079-10
(2002)
Electrical apparatus for explosive gas atmospheresPart 10:
Classification for hazardous area.
IEC 60331-11
(1999)
Tests for electric cables under fire conditions - Circuit integrity -
Part 11: Apparatus - Fire alone at a flame temperature of at least750 C
IEC 60079-14
(2007)
Electrical Apparatus for explosive gas atmospheres Part 14:
electrical installation in hazardous area (Other than Mines)
IEC 60947-3
(2005)
Low-voltage Switchgear and Control gear - Part 3: Switches,
Disconnectors, Switch-Disconnectors and fuse-combination units.
NEMA FG 1
(1994)Fiberglas Cable Tray Systems (Revision to FG1-1993)
SOLAS (IMO 110E
2004)
International Convention for Safety of Life at Sea 1947, and its
protocol of 1988. Articles, annexes.
33 CFR 67(2004) Navigation and Navigable Aids.
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DNV-RPB-401
(2005)Recommended practice for Cathodic protection design
IS 2026 Part -1
1977Power Transformers: Part 1 : General
IS 11171 - 1985 Specification for Dry-Type Power Transformers
ABBREVIATIONS
CCE Chief Control of Explosive
CCTV Closed Circuit TelevisionCP Cathodic Protection
ESP Electrical Submersible Pumps
LV Low Voltage
HV High Voltage
LCS Local Control Station
kV Kilo Volts
kW Kilo Watt
HMI Human Machine Interface
IMCS Integrated Motor Control SystemP&ID Piping and Instrumentation Diagram
MCT Multi Cables Transit
ONGC Oil and Natural Gas Corporation
API American Petroleum Institute
BIS Bureau of Indian Standards
ASTM American Society for Testing of Material
NFPA National Fire Protection Agency
IALA International Association of Marine Aids to Navigational and
Lighthouse Authorities
ANSI American National Standards InstituteSOLAS Safety of Life at Sea
NESC National Electric Safety Code
DNV Det Norske Veritas
NACE National Association of Corrosion Engineers
IEC International Electrotechnical Commission
NEMA National Electrical Manufacturers Association
IEEE Institute of Electrical and Electronics Engineers
NEC National Electric Code
BSI British Standards Institution
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BASEEFA British Approvals Service for Electrical Equipment for Flammable
Atmospheres
UL Underwriters Laboratories Inc.
FM Factory Mutual Research Corporation
SLD Single Line Diagram
VFD Variable Frequency drive
HMI Human Machine Interface
HPMV High Pressure Mercury Vapour
In the event of conflict between codes being used, the most stringent one shall be
followed.
4.0 GENERAL REQUIREMENTS
4.1 Well platforms do not have their own generating source of electrical power to meet the
requirements of electrical drive, communication and instrumentation equipments, platform
illumination, fire and gas system etc. Well platforms shall be connected to a nearby process
platform or well platform already connected to cable for electrical power. This designbasisbroadly outlines the minimum requirements for the design, selection, sizing on the well
platforms connected to process platform by submarine power/composite cable and also the
process platform for the modification purpose .
The electrical systems on well platform shall be designed to provide safety to personnel,
equipments, safety to personnel, equipments, reliability of service, minimal fire risk, ease of
maintenance, remote operation of electrical breakers, automatic protection of all electrical
equipment through selective relaying system, adequate provision for future expansion and
modification, fail safe features.
4.2 Site Conditions
All electrical equipment and accessories / material shall be suitable for installation and
operation under extremely saline, humid, corrosive and hostile marine environment with
specified degree of hazard.
In general, all outdoor electrical equipment shall be designed for 40 deg C temperature
and maximum 90% relative humidity while the indoor equipment shall be designed for 45
deg C and maximum relative humidity of 90%.
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4.3 Fire Integrity
All cable penetrations through firewalls, switchgear room walls and between safe and
hazardous area shall be sealed using Multi Cable Transits to maintain fire integrity of the
system and prevent gas migration. Multi Cable Transit shall be fitted where cables pass
through:
a) Decks and walls to open air
b) Fire walls
c) From safe to hazardous area
Such cable transit frames shall be designed to include 25% spare capacity for future use .
Cable transit frames are to be supplied with test certificates from an accredited
independent test authority to confirm a fire and blast adequate for the deck or wall in
which they are to be installed.
4.4 Design Life
The electrical system including CP System shall be designed for reliable and trouble freeperformance for 25 years of design life.
4.5 Material, Workmanship & Suitability
All material to be used in the construction of electrical equipment, cables, mounting and
fastening devices, etc., shall be of latest specifications, new and in manufacturers current
production. Should any material proves unsatisfactory it is to be rejected notwithstanding
any previous satisfactory examination on test of similar material or of equipment.
4.6 Units and Information
All quantities shall be expressed in SI / metric units. All information, manuals,
certificates, data and inscriptions shall be in English language.
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5.0 ELECTRICAL SYSTEM DESIGN
5.1 Electrical Loads
5.1.1 Utilization Category
Loads shall be divided into following three classes according to usage.
Continuous - Loads which draw power at continuous rate.
Intermittent - Loads which draw power for a fraction of time given by the duty
cycle of the load.
Standby - Loads which are connected with power supply and ready to act as
and when required.
5.1.2 Load Assessment
An electrical load list shall be developed by contractor based on estimated load as
identified in mechanical equipment list and the electrical loads envisaged. This data shall
be used to design the capacity of the power transformers and the switchgear configuration.
In evaluating load summary, utilization category is applied as follows:
a) Continuously operating equipment- 100% of operating load
b) Intermittent load - 50% of the total intermittent load or the largest
intermittent load, whichever is greater
c) Standby equipment - 10% of total standby load or largest standby
load, whichever is greater
d) Margin for future load growth - 10% of sum of (a), (b), (c) above
The total load shall be sum of (a), (b), (c) and (d)
5.2 Generation and Utilization Voltage Levels
5.2.1 Voltage Level Classification
a) Low Voltage (LV) - Up to 1000 Volts
b) High Voltage (HV) - Above 1 KV and up to 33 KV
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5.2.2 Generation Voltage Level
The generation voltage on a process platform in ICP is 6.6 KV and in MSP 11KV.
5.2.3 Utilization Voltage Levels (Nominal)
Sl.No Voltage Description
a) 6.6 / 11KV AC, 3 , 50 Hz For motors rated 150 KW and above
b) 440 V AC, 3 , 50 Hz For motors rated at 0.37 KW up to 150KW,
Pressurization and ventilation system,
battery chargers, Heat tracing, etc.
c) 250 V AC, 1 , 50 Hz For motors rated below 0.37 KW, Anti-
condensation space heaters, Convenience
outlets, etc.
d) 240 V AC, Phase to Phase Platform Illumination System (Normal
Lighting)
d) 110 V DC, 2 wire Critical lighting, Switchgear Controls,
Telephone System etc.
e) 24 V DC, 2 wire Instrument supply, Fire & Gas detection
system, Video Monitoring (CCTV) system,
Communication system, etc.
f) 12 V DC, 2 wire Navigational Aids system
5.3 Calculation Methods
5.3.1 Faults levels
As part of detailed engineering, initial fault current calculation shall be carried out based
on typical vendor data for machine parameters, cable parameters of the sub-sea cables,
taking account of design tolerances. However, minimum fault current of HV bus bar shall
be 25 KA for 1 sec. The calculations should identify the maximum expected values of
switchgear making and breaking fault currents. Calculations are to be done as per IEC
60909. Switchgear are to be designed such that actual fault levels are at least 20% below
the switchgear ratings, considering transient, fault break, fault make and peak fault levels.
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Calculations shall be checked by:
a) Preliminary hand calculations to test the order of magnitude of results
b) Computer modeling of the power system using internationally recognized software
Final calculations shall incorporate actual equipment data.
5.3.2 Cable Sizing
During the detailed engineering, all power and control cables shall be identified and sized
according to the requirement of Indian and International standards. All main power cables
on the platform, including feeders to switchboards and MCCs, tie cables between
switchboards and all HV motor cables shall be individually calculated and sized.
The sizing calculations shall take into account the following design criteria:
Connected load
Current carrying capacity
Voltage drop
Short circuit temperature rise for HV and main feeder cables. Laying conditions
Wherever possible, power cables and control cables should be run separately or with
adequate spacing.
Conductor current rating shall be established on the basis of 125% of design load current
at an ambient temperature of 40oC and de-rated for grouping and method of installation.
The voltage rating of cables shall be as per the standard international practice for the
utilization voltages defined.
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5.3.3 Voltage Drop
a) The maximum allowable voltage drop in any feederload on the same platformunder
steady state condition is to be maintained as follows:
Description Allowable Voltage drop
Motors 3%
Switch Boards / Distribution
Boards, Lighting / Power Panels
1%
Lighting Points 2%
DC System 3%
b) The voltage available at motor terminals during start-up shall be sufficient to ensure
positive starting and acceleration to full speed by the motor (even in fully loaded
condition of motor, if required) without causing any damage to the motor. However,under no circumstances, the voltage at motor terminals during starting is allowed to
fall below 80% of the nominal voltage.
5.3.4 Lighting Levels
Lighting levels shall be designed to meet Indian standards supplemented by the
requirements of API RP 14F and shall include a further 10% design allowance to cover
lamp deterioration and dirt accumulation on the fixture lens over a period of time.
The minimum illumination levels recommended by IES (illumination Engineering
Society) as per API-RP-14F, is as tabulated below:
Area Minimum Lighting level
for Normal Lighting (Lux)
Staircase/ Walkways 20
Open deck area 50
Open process area 50
Electrical Switchgear room/
battery Room/ VFD room 300
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AreaMinimum Lighting level
for Critical Lighting (Lux)
Staircase/ Walkways 20
Open deck area 5
Electrical Switchgear room/
battery Room/ VFD room50
5.4 Earthing
Power System earthing shall be as given below:
LV (AC) - Neutral solidly grounded
HV (AC) - Neutral grounded through low resistance
Plant earthing shall be as per API-RP-14F. Double earthing (two independent earth
connections to earth grid) for all electrical equipments shall be used. Double earth bonding
shall be required for all metal equipments and structures. However, the lighting fixtures
shall be wired with 3 core cables (2 phases and earth). Where cables are not used,separate earthing wire of same size as phase and neutral shall be run for earthing the
lighting fixtures.
The minimum size of earth bonding conductors on local control station enclosures shall be
6 mm2. The minimum size of earth conductors for electrical panels shall be 16 mm2.
Vessels, tanks, and mechanical packages not directly welded to the structure shall be
bonded to structural earth pad or boss using at least two independent 70 mm2 conductors.
Items such as pipes and duct work that have insulating material (i.e. gasket) betweenconnected sections shall be made electrically continuous by bonding with a 6 mm2
earthing cable or equivalent earthing strip.
All electrical panels shall be provided with a tinned copper earth bar.
5.5 Plant Layout
Switchgear room shall be located in safe, non-hazardous and well-ventilated area.
Ventilation and pressurization system as described in the basic bid work shall be provided
in these switchgear rooms. All electrical equipment in the switchgear room shall be
designed considering inadequate ventilation in the room.
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All batteries shall be located in battery room. The battery room shall be located in safe
area. Batteries shall be designed considering inadequate ventilation in the room.
The Contractor shall install electrical equipments only in approved locations, with due
consideration of the following:
Lighting fixtures shall be fitted so that they can be serviced and removed by a single
person.
Cables and cable ladders shall not be fixed to gratings or handrails.
Cables shall be properly tied in FRP cable trays at 600/800 mm interval.
Stainless steel tags shall be provided at each bend, near terminations and while passing
through wall/MCTs or one deck to another.
Cable tray height must be minimum 2.5 meters for safety and convenience.
The minimum clearance between electrical equipment or between other items and
electrical equipment shall be as tabulated below:
SI
No.
Description Clearance
A Floor Mounted Equipment
1 Front clearance for HV, Switchboards 2000 mm
2 Front clearance for all other switchboards / panels 1500 mm
3 Rear clearance for panels having only front access Maximum 50 mm
4 Rear clearance for panels 1000 mm
5 Side clearance between two switchboards (but not less
twice the width of each panel)
1500 mm
6 Side clearance between switchboard and nearest
obstruction
1500 mm
7 All around clearance for transformers 1000 mm
B Wall Mounted Equipment
1 Front clearance 1000 mm
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C Battery Bank
1 Battery rack to wall clearance for following arrangements:
1.1 Single row, single/double tier 100 mm
1.2 Double row, single tier 100 mm
1.3 Double row, double tier 750 mm
2 Rack to rack front clearance 750 mm
3 Rack to rack side clearance < 150 or >
750mm
D General
1 Head room clearance for all above equipments excepting
transformer
800 mm
2 Head room clearance for transformer in transformer room 2000 mm
6.0 POWER SYSTEM
6.1 Main Power
6.1.1 Main Power requirement for the platform shall be sourced from process platform to well
platform by submarine composite cable. Power transmission shall be at 6.6 / 11 KV. This
shall be stepped down by two identical HV/440 V 3 phase cast resin copper wound indoor
distribution transformers. Each transformer shall be designed to supply the whole
electrical power of the well platform independently with of 10% for future load growth.
However, minimum power rating of each transformer shall be 100 KVA. The transformers
shall be complete with all accessories, marshalling box, off load tap changer (OLTC). The
OLTC shall be able to compensate for voltage variations in all conditions ranging fromfull load to no load. The Transformer tapping shall be of range 5% in 2.5% steps in RS
15 & RS 16 platform and 10% in 2.5% steps in RS 17 platform.
6.1.2 The project specific requirements are as follows
6.6 KV, 3 core 400 sq.mm with 24 Core fiber optic composite cable shall be connected
from ICP process platform to unmanned SMART well platform RS17.
11 KV, 3 core 70 sq.mm with 24 Core fiber optic composite cable shall be connected from
MSP process platform to unmanned SMART well platform RS16.
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11 KV, 3 core 50 sq.mm with 24 Core fiber optic composite cable shall be connected from
unmanned SMART well platform RS16 to unmanned SMART well platform RS15.
6.1.3 The Transformer shall be connected to 440V, 50 Hz, 3 phase & neutral LV switchboard
with two incoming, one bus coupler and required number of outgoing circuits.
6.1.4 A parallel redundant 24 V DC Battery Charger system for Video Monitoring System
(CCTV) / platform surveillance system, instrumentation loads and communication with
Ni- Cd battery banks with a backup time of 24 hrs shall be provided.
6.1.5 A parallel redundant 110V DC Battery charger system for Switchgear control, Telephone
system & Critical Lighting with back up of 24 hrs shall be provided.
6.1.6 A parallel redundant for 12 V DC Nav-aid system (considering an operation of 14 hrs/ day
with 7 days backup) shall be provided.
6.1.7 Two nos. Lighting Transformer with 440 V/ 240 V phase to phase shall be provided and
connected to a lighting distribution board for lighting purpose.
6.1.8 Small Power and Space Heaters Distribution panel shall be fed from LV switchgear and
shall be 440 V 3phase 4 wire 50 Hz.
6.2 ESP Power
A separate switchgear room having pressurization and ventilation system with space
requirements for future transformers and VFD panels for supply to ESP in RS17 well
platform, shall be considered.
6.3 Critical Power
Critical supply for the platform shall be met by various DC Systems to be provided on the
platform.
6.4 Power Distribution System
Overall power distribution of the platform shall generally be as per the indicative power
distribution scheme described in the scope of work. The power distribution system for RS
15, RS16 & RS17 platform shall be as per Overall Single Line Diagrams COWGD725-75-
1-RS15-1001, COWGD725-75-RS16-1001 and COWGD725-75-1-RS17-1001.
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6.5 D.C. System
6.5.1 Separate battery banks with battery chargers shall be provided at RS15, RS16 & RS17
platform for 110V, 24V and 12V DC System to meet the DC power requirement. All
battery banks shall have 10% spare capacity to meet future load growth requirements. The
DC systems where 2 nos of Battery chargers are provided shall be of dual redundant
configuration.
6.5.2 DC power system for communication and instrumentation loads such as telemetry &data
transmission system, video monitoring system, gas detection, well shutdown control, well
testing , critical lighting, Telephone system, Switch gear controls,etc., consisting of Ni-Cd
batteries with battery rack, battery chargers shall be designed as per FS 4023. Back up
time for this system shall be 24 hours.
6.5.3 The navigational aid along with associated Ni-Cd Batteries with battery rack, battery
charger shall be provided on the platform as per FS 4023. Battery for Navigational Aids
shall have backup time of 7 days
6.5.4 The video monitoring system shall be designed as per specification. The video data shallbe sent to process platform through fiber optic cables as described elsewhere in the bid
package.
7.0 SPECIFIC REQUIREMENTS FOR EQUIPMENT AND ASSOCIATED COMPONENTS
7.1 Corrosion
For outdoor locations, corrosion resistant material shall be considered for electrical
equipment. As a minimum material / equipment requirements shall be as follows:
Cable ladders and trays shall be of fiberglass reinforced plastic and UV protected.
Explosion proof junction boxes, light fittings, control stations, etc., shall be
manufactured from cast stainless steel or copper-free aluminum with an epoxy finish.
Cable glands shall be nickel plated brass or equivalent.
All electrical panels shall be epoxy coated.
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7.2 Degree of Protection
The degree of protection against dust and water ingress, necessary for individual electrical
items will be determined by the equipment duty, its environment, its location and the
hazardous area classification. The equipment located outside or those subject to deluge
from fire water system shall be of weather proof construction and protected against the
most adverse conditions that are anticipated. These enclosures are to be classified to IP-56
as a minimum degree of protection, increased as necessary where the location/situation
demands. Indoor equipment will be a minimum of IP-42 protection and accessible
equipment within enclosures will be a minimum of IP-20 degree of protection. Where
indoor has specific ventilation requirement lower ingress protection rating may be
considered subject to approval by the company. The degree of protection for Transformer
indoor shall be IP 23 and for outdoor IP45.
7.3 Hazardous Area Classification and Equipment Requirements
7.3.1 The hazardous areas Classification shall be in accordance with API-RP-500 (1997)
Contractor needs to follow any one standard throughout the project.
7.3.2 Hazardous area classification drawings of the platform shall be prepared by the Contractor.
All equipments on the platform shall be designed for the respective area in which it shall be
installed as shown in the approved area classification drawing.
Selection of Electrical Equipment shall be done
a) As per Section 4 of API RP 14 F if area classification is as per API-RP-500.
b) As per API RP 14FZ / IEC 60079-14 if area classification is done as per IEC 60079-10.
c) Increased safety (Ex e) equipment shall not be used in class 1 Division 1 or Zone 1
areas.
7.3.3 All the equipment selected for use in Hazardous area shall have surface temperature limited
to 200C (T3). All equipment meant to be used in hazardous area shall be certified by
BASEEFA, UL, FM, CMRI or an internationally Recognized Certification Agency for the
area and service in which they could be used.
7.3.4 Outdoor equipment which are required to be powered during an emergency shall be suitable
for Class1 Division 1 or Zone - 1 irrespective of their location.
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7.4 Allowance for future / spare capacity:
In general a spare capacity of 20% shall be provided in switchboards and distribution
boards.
7.5 LV Switchgear
Feeders for 400 ampere rating or more shall be provided with ACBs. Feeders for more
than 63 ampere rating and up to 400 ampere rating shall be provided with MCCBs.Feeders up to 63 ampere rating shall be provided with MCBs. However, all motor feeders
below 63 amps shall have only MCCBs regardless of ampere rating. Bus bar and isolating
devices shall be rated at 125% of design load. Bus bars are generally identified as R, Y &
B with phase colored as red, Yellow and blue. All the switchgears shall be industrial
grade equipment installed in freestanding sheet metal cubicles of modular design.
Protection relays for main incomer circuit breakers shall be intelligent relays with serial
communication to the process platform. It shall be possible to remotely operate and
control the main incomers from process platform.
Electrical Switchgear shall be installed in non air conditioned room and hence shall bedesigned for high humid and corrosive atmosphere. The panels shall be EPOXY painted.
7.6 HV Switchgear:
6.6/11 KV, 50 Hz, 3 phase, sheet steel enclosed floor, mounted switchboard as per
functional specifications shall be installed. All HV switchboards shall be complete with
VCB/SF6 Circuit breakers, intelligent numerical relays, meters, components etc. for
power distribution to various switchboards / panels etc. All feeder panels shall be digitally
communicable. It shall be possible to remotely operate the circuit breakers from the
associated process platform. Communication interface for this is described in the basic
bid work. All protection relays shall be numerical relays capable of communicating
digitally with network equipment (network switches). For details, refer to basic bid work
of communication and Instrumentation lt. shall be possible to reset and configure all
relays remotely through this digital communication interface from the process platform.
All upstream and downstream relays shall be properly coordinated so that faults are
discriminated. A well designed relay co- ordination scheme shall be implemented as per
international standards for proper discrimination of fault. The protection schemes shall be
approved by ONGC before procurement of any related items. The panels shall be EPOXY
painted.
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7.7 HMI
A communication and control network along with an HMI system between the Process
platform and well platform through fiber optic shall be designed and Installed by the
contractor. The detailed network architecture shall be designed by the contractor and the
same shall be got approved from ONGC before procuring of the items.
The following functionalities are envisaged as minimum.
It shall be possible to open, close all HV and main incoming LV breakers at the well
platform remotely from the process platform.
It shall also be possible to monitor breaker status (such as opened / closed / trip) from
the process platform for all HV feeders and incoming LV feeders.
lt shall be possible to monitor and configure the relays of HV and main incoming L V
breakers at the Well platform remotely from the process platform.
lt shall be possible to monitor voltage, current, power factor, power and energy
consumption for the main incoming HV feeder remotely from the process platform.
It shall be possible to monitor trip circuit healthy and DC failure for HV Switchgear
and incomers of LV Switchgear.
In addition, the following functions of well platform shall also be monitored from process
platform
Video monitoring system
Monitoring and control Pressurisation and ventilation system of all platforms
Monitoring and control of ESP system for RS17 Well platform.
o ESP controls: Pump start, stop (normal), speed raise/lower, emergency stop,
fault reset.
o ESP indications: Motor current, Motor frequency, Drive ready to run & Drive
running, Drive alarm, Fault / Drive tripped, Pump alarm and pump tripped.
The monitoring and controlling system shall have 20 % spare capacity for future addition
of feeders. This HMI shall be located at process platform. Laptop for trouble shooting at
well platform shall be provided.
7.8 Power Transformers
7.8.1 The main LV switchgear is supplied from two transformers enabling either transformer to
accept the entire LV load. The transformers shall be sized, using the natural air-cooled
rating. Each shall be rated for 110% of the predicted distribution design load.
Transformers shall normally be Dy connected, natural air cooled, cast resin dry type
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vector group Dyn-11. Minimum power rating of each transformer shall be 11 KV or 6.6
KV /440 V, 100 KVA.
7.8.2 The power transformers shall be located in a transformer room in RS15, RS16, RS17 with
suitable ventilation (Grilled rolling shutter shall be provided). However in RS17 the VFD
transformers for ESP shall be located in a completely enclosed room with pressurization
and ventilation.
7.8.3 Two lighting transformer of 3-phase, 440 V /240 V AC 50Hz, AN, Dy11, cast resin dry
type shall also be provided upstream of Lighting, and shall be located in the Switchgear
room with pressurization and ventilation.
7.9 Electric Motors
Continuous output rating of motors shall be at least 110% of the maximum shaft KW
demand of the driven equipment.
7.9.1 LV Motor
All LV motors shall be totally enclosed fan cooled (TEFC) motors with class F insulation,
temperature rise limited to class B. Selection of motors for Hazardous area shall be as per
section 7.3 above (Hazardous area requirements).
Any motor rated 75 kW and above, shall be fitted with positive temperature co-efficient
thermistors. If motors are used with variable speed drives, they shall also be fitted with
positive temperature coefficient thermistors. Motors rated 3.7 KW or above are to be
fitted with anti-consideration space heaters which will be energized when the motor is not
running.
7.10 Lighting
7.10.1 The lighting fixture shall be as per area classification. Lighting system shall consist of
normal lighting and critical lighting. Critical lighting shall have backup of 24 hours.
7.10.2 Voltage level shall be 240 V AC line to line for normal lighting and 110 V DC for critical
lighting. Power for the lighting shall be drawn through two lighting transformer
(secondary voltage is 240 V between lines) installed in the switchgear room (refer 7.8.3
above). Each lighting transformer shall be rated to supply the complete lighting power
independently.
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7.10.3 Normal and critical lighting system for Electrical/ Instrumentation room, Battery room,
bunk house, pig launching/receiving area shall be provided. Lighting levels shall be
designed to meet Indian standards supplemented by the requirements of API RP 14 F and
shall include a further 10% design allowance to cover lamp deterioration and dirt
accumulation on the fixture lens over a period of time.
7.10.4 Critical lighting shall provide a minimum horizontal level of illumination as per API RP
14 F (standby lighting). Critical lights shall be fed through the chargers. All Critical
lighting fixtures shall be suitable for class1 Division 1 Gas Group D Temp class T3 (as per
API RP 500) or for Zone 1, Gas Group IIA and IIB, Temp Class T3 (as per IEC 60079-10)
7.10.5 Type of lighting fixtures shall be restricted to minimum and shall preferably be supplied
from one vendor. Lighting fixtures shall not be based over rotating equipment. Indoor non
hazardous area shall be provided with industrial fluorescent luminaries. External areas of
platform shall be provided with fluorescent luminaries suitable for the area classified but
as a minimum shall be for class 1 division 2. Critical lighting shall be provided by 100 W
Incandescent Well glass lighting fixtures. Ingress rating of these fittings shall be
minimum IP 56.
7.10.6 Total 6 Nos flood lights (flame proof HPMV of minimum 400 W) shall be provided in
Main deck (2 Nos), cellar deck (2 Nos) and boat landing (2 Nos). Proper access platforms
with vertical caged ladders shall be provided for the same.
7.11 Protection Equipment
7.11.1 Transformer Protection
The following protections shall be provided for transformers as a minimum.
Earth fault and Over current protection
Over temperature protection
7.11.2 Motor Protection
LV motor starters incorporate the following protective devices:
MCCB for short circuit
Single phasing prevention
Earth fault protection for motors above 37.5 KW
Overload
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7.11.3 LV Feeders
ACBs/ MCCBs used for LV feeders shall have short circuit and over load protective
devices. MCCBs / MCBs used for DC incomer feeders and DC distribution feeders are to
be provided with short circuit and overload protections as a minimum.
7.12 Socket Outlets
7.12.1 Two types of socket outlets are provided on the platform.
440 V, 50Hz, 3 wire plus earth 63 amp, 4 pin for welding sets
250 V, 50Hz, 2 wire plus earth, 15 A, 3 pin
They shall generally be industrial type, metal clad and surface mounted construction,
however, the sockets provided in control rooms and building areas shall be decorative
type. These outlets provided outdoors shall be as per clause 7.3. The number of socket
outlet for 15 Amp shall be such that at least one outlet is available for every 15 meters
distance. 63 Amps welding outlets shall be such that any point on the platform can be
reached using a 50 meters cable. Socket outlets shall be provided with earth leakage
protection, 30mA for 250 V, outlets and 300mA for 440 V, welding outlets via dedicateddistribution board.
7.12.2 250 V socket outlets shall be considered indoor and not for outdoor areas for the well
platforms and the indoor sockets shall be connected from a dedicated distribution board.
The 440 V socket outlet shall be considered only for outdoor and shall be fed from the LV
Switchgear.
7.13 Junction Boxes and Start/Stop Control stations (Push button stations)
Junction boxes and Start/Stop Control stations shall be provided as per clause 7.3 and
fabricated from the following material.
SS-316
Epoxy coated copper free aluminum
They shall be suitable for service during the entire life of the platform.
The cable entry glands are nickel plated brass material and of double compression type
with Ex (d) protection.
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7.14 Cables
Cable shall be heat and oil resistant, flame retardant (HOFR) type suitable for service in
environmental conditions described for the platform. All (normal and emergency) cables
have flame retardant characteristics to IEC 60332-3 category A.
Cables for safety systems like critical lighting system, navigational aids, F&G system and
Communication system shall be fire resistant type to the requirement of IEC 60331.
Cable joints via cast resin kit or other type are not permitted on the offshore installations.
Special care shall be taken to the routing and separation of cables to minimize the effect of
fire on emergency and essential supplies and production operations.
All cables are identified with SS316 Tags.
In addition, the minimum distance between power/control wiring and electronic signal
wiring on prolonged cable route will be as follows:
Power / Control Cable Minimum distance from electronic /
signal cable
Up to 125 V 150 mm
Up to 300 V 150 mm
Up to 1000 V 300 mm
Above 1000 V 450 mm
7.15 Earth Conductor
Earth cable shall be 6 mm2, 16 mm2, 70 mm2, or 240 mm2, stranded copper conductor with
CSP or EVA insulated with green / yellow insulation sheath.(Also refer section 5.4)
7.16 Cable support System
The cable system comprises cable installed on cable tray or ladder with 25% spare
capacity for future extension.
HV cables shall be installed on dedicated trays/ladders.
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Intrinsically safe circuit cables shall be separated from other cables by 50 mm spacing or
metallic barrier.
Cable straps or ties shall be of SS-316.
7.17 Cable Tray/Ladder
Fourprimary cable tray / ladder system shall be installed on the platform wherever
possible. However, in case of space restriction low voltage power and control cable shall
be considered in the same tray with adequate spacing.
High voltage
Low voltage power
Control cable
Instrumentation, communication and ESD
The cable trays / ladders shall be heavy duty type capable of being loaded to 120 kg/m
with 6 m support spans to NEMA 20B. Cable ladders/trays are to be manufactured from
FRP material with UV protection features.
Cable ladders are fitted with removable, ventilated covers where there is exposure to
chemical spillage, falling object or direct sunlight. The covers are suitable for cyclone /
monsoon conditions.
Cable trays shall be installed in accordance with manufacturers recommendations and
specifically supported each elbow. The overhead cable trays shall be installed a minimum
of 2.5 meter above deck.
7.18 Cable Glands
Suitable size double compression type glands shall be supplied for all cables. For entries
into Ex (d) enclosures, barrier type (or compound filled) glands shall be provided. All
cable glands and adaptors will be made up of nickel plated brass and shall be fitted with
soft sealing nylon washer. Fiber washers shall not be used. Lock nuts shall be used for
entry into sheet steel boxes and enclosures. Cable termination shall be made with Tinned-
copper lugs.
Industrial cable glands are not used on offshore platforms. All cable glands are to be type
tested and certified of use in specified hazardous area.
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7.19 Cathodic Protection
Cathodic Protection for Structures and J-tubes shall be designed in accordance with the
functional specifications enclosed in the bid package.
7.20 Navigational Aids
4 Nos. Nav-aid lanterns (1 at each corner of the platform) shall be provided in each well
platform.
The Navigational Aids and its Junction box shall be suitable for a hazardous area of Class
1 Division 2.
7.21 Video Monitoring system
Four new cameras shall be located in each well platform and shall be integrated to the new
console located in the existing process platform through the fibre optic cable.
7.22 Electrical Heat Tracing for RS15 & RS16
7.22.1 The process and piping documents specify the operating temperature range for each
piping. For electrical heat tracing design/calculations, the maximum operating temperature
specified shall be considered as maintenance temperature i.e. for operating temperature
35- 75C, maintenance temperature shall be 75C.
7.22.2 The minimum temperature for heat tracing design/calculations shall be considered as
30C as per process requirement.
7.22.3 Hot insulation compatible with the electrical tracing shall be used. Insulation details i.e.
type of insulation and thickness shall be as indicated in the piping documents.
7.22.4 The fluid data to be considered for heat tracing design shall be as per the Process input.
7.22.5 Thermostats shall have adjustable settings and shall be mounted at accessible
positions/places. Heat tracing system shall be designed in such a way that the temperature
of pipeline at any stage shall not exceed the temperature indicated in the Process
documents.
7.22.6 The tracer for instruments, valves, flanges and vessels shall be provided with adequate
looping of heat tracer tape, in order to facilitate removal of heater tracer tape for
maintenance.
7.22.7 The heat tracer and accessories shall be certified for use in Class 1, Division 2, Gas Group
D (Zone 2 Gas Group IIA, IIB) Temperature Class T3 hazardous area.
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Functional specifications and electrical design basis in respect of each individual
equipment
Applicable Standards, Codes & Recommended Practice
Reliable & trouble free performance for 25 years of design life
Safety
General Operating / Site conditions
Hazardous area classification
Suitability for the specified requirement for use in outside pressurized rooms and
inside pressurized rooms
Suitability for the corrosive effects of the saline and humid marine atmosphere,
galvanic action, etc.
9.0 ELECTRICAL EQUIPMENT CALCULATIONS
Certified calculations, as listed below, for electrical equipments of well head platform in
respect of size / rating / power / capacity, etc., are to be provided by the contractor for
approval of ONGC during Detailed Engineering:
Transformers (Load List)
Electric Motors (SLD, Load list)
Switchgear and control gear(SLD)
Power and control cable (Cable sizing)
MCTs (MCT schedule)
Area lighting fixtures (Lighting Calculation)
Cable trays (Cable tray layout)
Battery & Battery Charges for various system (by Battery system Vendor)
Earthing cable/conductor (Legend and Notes for Earthing)
Lighting transformer (Load list)
Cathodic protection system (by CP system Package Vendor)
These calculations form part of the relevant Purchase Specification to be submitted during
detailed engineering.
10.0 REVIEW AND APPROVAL
All Purchase Specifications along with list of deviations calculation sheets, offers of the
vendor and all relevant documents are to be furnished for ONGCs approval during
detailed engineering. Contractor is advised not to place order for purchase of any item
without obtaining prior approval from ONGC in writing.
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Contractor prepares and furnishes the list of all drawings / documents enlisted in the bid
document for document for ONGCs review. The category of drawings / documents (i.e.
whether to be reviewed / approved by ONGC is generally decided in consultation with
contractor and ONGCs consultant after award of Contract.
All vendor drawings are to be submitted for ONGCs review after the contractors
engineering consultant approves them.
11.0 TAGGING AND NAMEPLATES
All equipment (Motors, push buttons, motor control centers, push button stations, pull
boxes etc.) are provided with SS tag or nameplate of a permanent type with identification
number and service description.
The Contractor assigns individual tag numbers in accordance with ONGCs established
system to all electrical equipment. The tag number that pertains to a electrical equipment
appears invariably on all drawings and documents.
Nameplates and identification tags are to be provided to properly identify each equipmentand / or their component.
All panel electrical equipment nameplates are to be made up of white laminated plastic
plates with black engraved lettering and securely fastened with SS-316 screws.
All front panel mounted equipment are to be identified with a metal or plastic nameplate
attached to the rear of the device and easily device and easily visible via the rear access
doors.
All wiring, power and control cables, junction boxes and auxiliary equipment are to be
suitably identified as per applicable codes and practices. Plastic adhesive tapes are notused for identification. All wirings are to be tagged with slip on or clip on wire marker at
both ends with the wire number specified on the drawing.
12.0 ELECTRICAL EQUIPMENT INSPECTION & TESTING PHILOSOPHY
The contractors quality plan includes a comprehensive fully documented inspection and
testing plan specific to the project and it is to be submitted to ONGC for review and
approval. The inspection procedures include inspection specifically for compliance with
hazardous area requirements. The Contractor is also required to provide suitable
workshop, equipment and all necessary tests for electrical equipment.
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ONGC reserves the right to reject any or all test work, if found unsatisfactory/not up to the
mark.
In addition to yard testing of loop checking and setting for safety devices like overload
relays etc. and simulation testing of all interlock and shutdown systems, they are required
to be carried out in offshore also.
All testing and pre-commissioning activities are required to be done by the Contractor.
The Contractor is also required to provide assistance for ONGCs commissioning
activities.
The Contractor is required to provide written results of all above tests, it so required by
ONGC. Also, the contractor is required to furnish reasonable evidence of the satisfactory
condition of test equipments.
13.0 ELECTRICAL EQUIPMENT SPARES PHILOSOPHY
For all major equipment, the Contractor is required to include normal commissioning
spares as a part of the equipment. The Contractor is also required to furnish separately,list of recommended spares for two years trouble free operation along with the prices for
purchasers review.
The spares requirement of individual systems shall be as per the relevant functional
specification.
14.0 TRANSPORT AND SHIPMENT
All electrical equipment, cables and trays etc. are required to be securely anchored to the
skid. All equipments that could be damaged in shipment shall be removed, tagged and
crated in weather proof box. Weather proof box shall protect the equipment from dynamicforces.
All openings, flange thread connections and cables exposed as a result of cable removal
are required to be protected in a manner to prevent damage during shipment.
15.0 WARRANTY
All equipments and systems supplied by the contractor / his vendor is required to perform
satisfactorily and meeting all criteria as per specification. The warranty / guarantee from
the contractors side to this effect shall be governed by the warranty / guarantee clause
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mentioned in the general terms and conditions of contract and special conditions of
contract.
16.0 DOCUMENTATION
The contractor shall provide hard copies plus electronic copies on CD for all the
documents.
16.1 Equipment Documentation
The contractor shall provide the following documents as a minimum:
Engineering, Design and calculation books
Operating philosophy of the system and proposed maintenance schedule of all major
components, for the design life of the system including replacement requirements of
parts
Specifications, test certificates and data sheets for all items
Deviation schedule for items if any
Anode location drawings
Single line diagram, schematic diagram and functional wiring diagram of LV
Switchgear and all DC panels
Bill of materials
Cable and tray routing drawings and cable schedule
Earthing layout
Lighting fixtures and obstruction light layout drawings
Interconnection and hook up drawings
MCT frame drawing
Equipment layout drawing in electric room and as build drawings
Battery / Battery rack layout
Minimum 3 (three) sets of Dossier shall be provided to the Company.
The contractor shall be responsible for the authenticity of the drawings & data provided by
the vendor as well as sub-vendor(s).
Each vendor data items requested above must be identified by the Purchase Order number
and equipment tag number located on the cover sheet or first page of said item and in the
case of engineering drawings on each and every drawing.
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Any additional data/drawings required, as a result of issuing supplements to a purchase
order or during detailed engineering, shall be furnished by Vendor and handled in the
same manner as the original order.
All drawings and literatures shall be in English language and in the Metric Measurement
System.
The reproducible drawings, 279mm x 432mm (11 x 17) size and full size are to be of
such quality that clear legible prints can be made.
16.2 Electrical Equipment Index
The contractor shall provide an electrical equipment Index.
The index shall include the information listed below:
Electrical Tag Number
Service Description
Rating/type
Electrical drawing (single line, schematic and wiring Drawing)
Data Sheet Number
The electrical index shall form the basis for documenting all electrical drawing and shall
be listed in alphanumeric order of electrical tag number and shall contain all relevant
information for each electrical item. The index shall be based on Microsoft Access.
16.3 Electrical Equipment Data Sheet
A duly data sheet shall be provided by contractor for every item of electrical equipment,
including those which are part of packaged plant. The data sheet shall include but notlimited to the following:
Manufacturer name
Model/type
Standard and code reference
Electrical parameter details
Construction materials details
Performance details
Mechanical/physical details
General arrangement drawing showing electrical equipment and details of interface
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Test certificate
Hazardous area classification and certificate details (type of protection, certifying
authority)
17.0 MODIFICATIONS
In addition to the above the following shall also be applicable for modification in Process
Platform.
17.1 General Requirements
The offshore platforms generally have their own generating source of electrical power to
meet the requirements of process utilities and other electrical drives, living quarters,
platform illumination system, communication and annunciation system, fire and gas etc.
17.1.1 General Safety
The electrical system shall employ safety margins to ensure that platform is safe under all
operating conditions, including those associated with the start up and shutdown ofequipment and throughout intervening shutdown periods. The emphasis in equipment
selection is on operability, prevention of accident / fault and functionality for the intended
design life.
17.1.2 Evacuation
All services required for safe evacuation of the facility shall be designed to operate for
sufficient time after loss of both main and emergency power at the platform. The support
duration is in line with the risk assessment study.
17.2 Electrical loads
17.2.1 Voltage Level Classification
a) Low Voltage (LV) - Up to 1000 Volts
b) High Voltage (HV) - Above 1 KV and up to 33 KV
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17.2.2 Generation Voltage Level
The generation voltage on a process platform is usually 6.6 KV and in some cases 11KV.
Emergency power generation is generally at 415V.
17.2.3 Utilization Voltage Levels (Nominal)
Sl.No Voltage Descriptiona) 6.6 / 11KV AC, 3 ,
50 Hz
For motors rated 150 KW and above
b) 415 V AC, 3 , 50
Hz
For motors rated at 0.37 KW up to 150KW,
battery chargers, HVAC, bulk AC loads (like
Process heaters)
c) 240 V AC, 1 , 50
Hz
For motors rated below 0.37 KW, Platform
communication system, Anti-condensation
space heaters, Convenience outlets, Platform
Illumination system ( Normal Lighting etc.,)
d) 110 V DC, 2 wire Critical lighting, Switchgear Controls, DC
motors for Emergency lube oil pumps,
compressors UCP, etc
e) 24 V DC, 2 wire Instrument supply, Fire & Gas detection
system, etc
f) 12 V DC, 2 wire Navigational Aids system
g) 110 V AC, UPS Distributed Control System, ESD, FGS
h) 240 V AC, UPS Telephone Exchange, CCTV system, Radio
system, Paging & Intercom system, Telemetry,
telecom and computer system
17.2.4 Cable Sizing
LV Motor cables shall be selected from a standard Motor Cable Selection chart. . For
branch circuits and feeders, conductor current rating shall be established on the basis of
125% of design load current at an ambient temperature of 40oC and de-rated for grouping
and method of installation. Final sub-circuits shall be sized from standard cable selection
charts based on circuit breaker rating, and voltage drop limits.
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17.2.5 Lighting
The lighting system shall be designed in accordance with recommendations of
Illumination Engineering Society (IES) and to achieve minimum levels of illumination as
per API RP 14F. Power for the lighting shall drawn through a lighting transformer
(secondary voltage is 240 V single phase installed in the switchgear room.
Luminaries shall be circuited such that illumination in any area shall not be lost if one sub
circuit fails.
Type of lighting fixtures shall be restricted to minimum and shall preferably be supplied
from one vendor.
Mounting height and location of lighting fixtures shall permit ease of maintenance and
lamp replacement. Lighting fixtures shall not be located over rotating equipment.
Indoor non hazardous area shall be provided with industrial fluorescent luminaries.
External areas of platform shall be provided with fluorescent luminaries suitable for the
area classified but as a minimum should be for class 1 division 2. Ingress rating of these
fittings shall be minimum IP 56.
Floodlighting shall be provided for large and open areas such as main deck, jacket
walkways and boat landing etc. Proper access platforms with vertical caged ladders shall
be provided for the same.
Lighting for gauges shall be provided with local On/Off switch.
Lighting on the platform is divided into 4 categories, Normal lighting, Emergencylighting, Critical lighting and Special lighting. Each category is defined in the following
sections.
Normal illumination level is the total illumination provided by normal and emergency
lighting. DC lighting and Special lighting shall no be considered for this.
Critical illumination level is the total illumination provided by DC lighting only.
Emergency lighting shall not be considered for this.
All light fittings are to be secured and fastened using SS-316 fasteners and accessories.
The highest point on the platform is fitted with omni directional red obstruction light.
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17.2.5.1 Normal Lighting
Normal lighting on the platform shall provide safety to operating personnel and also
ensure effective and efficient job performance.
17.2.5.2 Emergency Lighting
Emergency lighting fixtures of fluorescent type with self contained battery / inverter
having duration of ninety (90) minutes shall be located near exit points, in buildings,
near rotating equipment and other areas.
Outdoor emergency lighting shall also be provided by using similar type of fixtures as
above. Ingress protection shall be minimum of IP56.
All emergency lighting fixtures will be suitable for Class 1 Division 1/ Zone-1, Gas
Group D.
Emergency light fittings shall be in accordance with IEC 60598-2-22 and hence shall
have battery autonomy of 90 minutes after 4 years of continuous operation.
17.2.5.3 Critical Lighting
DC critical lighting fixtures shall be provided in all areas to provide safe access for
personnel evacuation points and in the control and other building areas to permit
emergency operation for safe shutdown of the platform in the event of mains failure.
Critical lighting shall provide a minimum horizontal level of illumination as per API RP
14F (standby lighting).
Critical lights shall normally be kept ON and fed through the charger and beautomatically switched over to battery banks in case of AC failure.
All critical lighting fixtures shall be suitable for class 1 Division 1 Gas Group D Temp
class T3 (as per API RP 500) or for Zone 1, Gas Group IIA and IIB, Temp class T3 (as
per IEC 60079-10).
Lighting fixtures provided in each EXIT leading to walkways and life boat stations
shall be fitted with green lens.
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17.2.5.4 Special Lighting
In addition to the normal lighting, incandescent lamp AC fixtures shall be provided in
operational areas and these shall be powered by the output of a dimmer stat to vary the
voltage to the fixtures and consequently the illumination level which may be required in
a special situation. The dimmer stat shall be installed in the switchgear room and there
shall be provision to control the dimmer stat from remote. These incandescent fixtures
shall not be considered for calculations of normal lighting illumination level.
17.3 Power System
17.3.1 Main Power
Main Power requirement for the platform shall be source form one of the following:
a) Main generators installed on the new platform
b) Additional power, if available, from the existing bridge connected platform
Basic Bid Work (Electrical) enclosed in the Bid Package shall be referred for project
specified requirements.
17.3.2 Emergency Power
Emergency power requirement for the platform shall be sourced from one of the
following:
a) Emergency generator installed on the new platform
b) Additional emergency power, if available form the existing platform bridge
connected to the new platform
Basic Bid Work (Electrical) enclosed in the Bid Package shall be referred for project
specified requirements.
17.3.3 Critical Power
Critical supply for the platform shall be met by various DC Systems and UPS system to
be provided on the platform.
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17.3.4 Power Distribution System
Overall power distribution of the platform shall generally be as per the indicative power
distribution scheme enclosed with the basic bid work (Electrical).
17.3.5 Operating Philosophy
Please refer to the basic bid work (Electrical) for the operating philosophy for electricalequipment installed on the platform.
17.4 Protection Equipment
The equipment defined provides adequate safeguards against the effect of any fault
occurring on the system or component parts.
All protective devices, including relays and current transformers (CTs) etc. are to be
adequately rated to withstand the prospective short circuit current, which can flow or be
induced.
Unrestricted over current relays provided shall have IDMT characteristics of the
standardized type A, B or C in accordance with IEC 60255-4.
The relay protection devices are such that a clear indication is given of the fault which
caused at trip. Circuit breakers should not be able to re-close without first resetting the
appropriate master trip relay.
17.4.1 Modification of Existing Switchgear
The existing 11kV AC, 3Ph, 50Hz, 2200A, 50kA (1sec) HV Switchgear (M-5300 -ABB
Unigear make) Feeder number B05 in Switchgear Room at MSP Platform, spare motorfeeder shall be used to feed the new SMART Well Platforms RS-16 and RS-15.
The existing 6.6kV AC, 3Ph, 50Hz, 1200A, 40kA (1sec) HV Switchgear (201-Westing
House make) feeder number VS#10 in Switchgear Room at ICP Platform, spare motor
feeder shall be used to feed the new SMART Well Platform RS-17. For more details
please refer Pre-engineering Survey report COWGD725-30-GEN-105).
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17.5 Navigational Aids
If the platform is bridge-connected to an existing platform, Navigation Aid System of new
platform shall be synchronized to the Navigation Aid System of the existing platform. In
this project the MSP platform is bridge-connected to existing SA platform
17.6 Video Monitoring System
The location of the CCTV system at existing process platform control room of BHS and
ICP platform shall be as per pre-engineering survey report.
17.7 Telephone System
A new telephone system in the well platform shall be interfaced with the existing
exchange in the process platform.