B.2.2_Elec Design Guidelines

Sheet 1 of 43HINDUSTAN PETROLEUM CORPORATION LIMITED MUMBAI DHT PROJECT ENGINEERING DESIGN GUIDELINES ELECTRICAL DOCUMENT NO: 44LK-5100-00/E.02/0002/A4 Rev No. Issue Date Pages Rev Description Prepared By Checked By VDV VDV VDV Approved By RBD VDV VDV A B C 16.02.2008 29-08-2008 12-09-2008 43 43 43 Issued for Approval Issued for Engineering Revised after incorporating HPCL comments & Issued for FEED Approved by HPCL & Issued for Implementation MSJ MSJ MSJ 0 08-10-2008 43 MSJ VDV VDV ENGINEERING DESIGN GUIDELINES ELECTRICAL TABLE OF CONTENTS 44LK-5100-00/E.02/0002/A4 Sheet 2 of 43 Revision 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 SCOPE STATUTORY REQUIREMENTS, CODES & STANDARDS ELECTRICAL SYSTEM DESCRIPTION AREA CLASSIFICATION SYSTEM DESIGN PHILOSOPHY EQUIPMENT DESIGN PHILOSOPHY SYSTEM LAYOUTS INSTALLATION FIELD TESTING AND COMMISSIONING MAKE OF COMPONENTS 3 3 4 5 6 17 31 39 39 40 42 ANNEXURE – I :LIST OF REFERENCE STANDARD SPECIFICATIONS : ENGINEERING DESIGN GUIDELINES ELECTRICAL 1.0 SCOPE 44LK-5100-00/E.02/0002/A4 Sheet 3 of 43 Revision 0 This Engineering Design Guidelines along with the Engineering Design Basis Document No. 44LK-5100-00/E.02/0001/A4 shall form the basis for developing detailed design and engineering for electrical facilities included in the bid Document. All data required in this regard shall be taken into consideration for acceptable, satisfactory and trouble free operation of the system as per good engineering practices. Compliance with these specifications and / or review of any of the contractor documents shall in no case relieve the contractor of his contractual obligations. 2.0 STATUTORY REQUIREMENTS, CODES & STANDARDS The design and the installation shall be in accordance with established codes, good engineering practices and shall conform to the statutory regulations applicable in the country. Contractor shall be responsible for obtaining necessary approvals from the statutory authorities e.g. Electrical inspectorate, CCE as applicable before commissioning of electrical facilities. 2.1 The main codes, standards and statutory regulations considered as minimum requirements are as given below: Latest version of these shall be followed: Indian Standards OISD standards Indian Electricity Act Indian Electricity rules International Electro technical commission The Factory act The Petroleum Rules API Standards / IEEE Some of the bare minimum relevant Indian Standards / OISD Standards are as listed below. However, system / equipment design shall be in line with latest edition of all applicable standards. IS 5572 IS 5571 IS 12360 IS 13234 IS 3716 IS 9676 IS 3043 Classification of hazardous areas for electrical installations. Guide for selection of electrical equipment. for hazardous areas. Voltage bands for electrical installations including preferred voltages and frequency. Guide for short circuit calculations. Application guide for insulation co ordination. Reference ambient temperature for electrical equipment. Code of practice for earthing. ENGINEERING DESIGN GUIDELINES ELECTRICAL IS 732 IS 6665 IS 3646 IS 1944 IS 13346 IS 13408 44LK-5100-00/E.02/0002/A4 Sheet 4 of 43 Revision 0 Code of practice for electrical wiring installations system voltages not exceeding 650V. Code of practice for Industrial lighting. Interior illumination: Part I & Part II. Code of practice for lighting of Public through fares. General requirements for electrical apparatus for explosive gas atmosphere. Code of practice for the selection, installation and maintenance of electrical apparatus for use in potentially explosive atmospheres. Guide for control of undesirable static electricity. Code of practice for the protection of buildings and allied structures against lightning. Code of practice for fire safety of buildings and electrical installations. Code of practice for fire safety of industrial buildings - Electrical generating & distributing stations. National Electrical Code (NEC) - BIS Publication. Classification of areas for electrical installation at hydrocarbon processing and handling facilities. Inspection and safe practices during electrical installations. Design aspects for safety in Electrical system. Fire prevention and protection system for electrical installation. Lightning protection. Code of practice for fire protection of cable runs. IS 7689 IS 2309 IS 1646 IS 3034 SP 30 OISD 113 OISD RP 147 OISD RP 149 OISD 173 OISD GDN 180 IS 12459 2.2 2.3 Any other standard may be followed provided it is equivalent or more stringent than the standards specified above. In case of any conflict / deviation amongst various Documents the order of precedence shall as be as follows: Statutory regulations. Job specification. Design basis / Engineering Design Guidelines. Standard specifications, installation standards, etc. 3.0 3.1 ELECTRICAL SYSTEM DESCRIPTION Total power requirement of ISBL facilities (DHDT, HGU, SRU/ARU, and SWS/TGT) and OSBL facilities shall be catered by Tata Power Company (TPC) supply at 110 kV. Primary distribution to different substations for DHT project is at 6.6 kV. Secondary distribution is at 6.6 kV and 0.415 kV for HT motors / distribution transformers and LT load respectively. 3.2 3.5. overhead structures.95 shall be supplied.5 3. water ingress. etc.5.1 AREA CLASSIFICATION Following factors shall be considered for proper selection of electrical equipment for use in hazardous areas: Area classification (Zone 0 / Zone1 / Zone2) Gas Group classification (Gr. fabrication activities. etc.5.ENGINEERING DESIGN GUIDELINES ELECTRICAL 3.3 44LK-5100-00/E. EPCC contractor shall include adequately rated sub distribution boards.3 .0 4.6 kV system is designed for 450 MVA withstand for 3 seconds and 415 V system is designed for 35 MVA withstand for 1 seconds. which are to be supplied and maintained by the EPCC contractor. office.Other electrical apparatus specifically designed for Zone 1 Zone 2 . installed and maintained by the EPCC contractor. 4. Selection of equipment for hazardous areas shall be as follows: Area Classified Zone 0 Zone 1 Type of protection .2 All electrical equipment installed in classified areas shall be selected as per IS 5571.4 4. etc. For Zone 2 areas as a minimum Ex (e) type of equipment shall be used. It shall be EPCC contractor’s responsibility to maintain power factor more than 0.2 CONSTRUCTION POWER EPCC contractors shall make their own arrangement for construction power supply and power supply for office lighting purpose. for feeding loads to carry out construction.5.No electrical equipment to be installed.95 at all power distribution boards. EPCC contractor shall provide adequate area lighting at site of construction.02/0002/A4 Sheet 5 of 43 Revision 0 6. power supply cables. Power factor improvement capacitors as required for maintaining a power factor more than 0. flood lighting poles. .3 3.Flameproof enclosure . OISD-113 and other relevant standards.Pressurised . other associated material.Intrinsic safety category ‘ i ‘ .Increased safety ‘e‘ ‘d‘ ‘i‘ ‘p‘ ‘s‘ Symbol 4. trenches. by means of high flood light masts.1 3. road crossings etc.All Equipments suitable for Zone 1 . 3. fabrication yards. II A / IIB / IIC) – Characteristic of the gas / vapour involved Temperature classification (T1 to T6) Environmental conditions – selected electrical equipment shall be protected against corrosive and solvent agencies. chemically polluted atmosphere as determined by the environmental conditions. The power distribution boards shall be provided with ELCB / CBCT with ELR for all its feeders. dusty. UL / FM for the service and the area of installation and shall be approved by CCE.7. Increased safety apparatus located outdoor shall be provided with minimum IPW55 protection as per IS 4691. All electrical equipment installed inside a compressor shed where hydrogen is being processed / handled shall be flameproof type (Ex’d’) suitable for gas group-IIC for area being classified as Zone-1 and shall be increased safety type (Ex’e’) suitable for gas group-IIC for area being classified as Zone-2.7.7. All electric motors for agitators. As additional safety features.7 4. irrespective of zone classification of zone 1 or zone 2. Light fittings in hazardous areas shall be with EX ’d’ enclosure only. 4. Even though fired heaters in process units are not considered for area classification.6 4.visual alarm. electrical equipment shall be switched off with audio . BASEEFA.11 5. on failure of pressurisation system. All indigenous flameproof equipment Ex (d) shall be under BIS license.5 4.7. Irrespective of the area classification (whether Zone-1 or Zone-2) all motors and lighting fixtures within the storage areas. All equipment inside the process units shall be suitable for Zone-2 and shall be increased safety Ex (e) & temperature class T3 irrespective of area being safe. All electrical equipment installed for an analyser room shall be flameproof type Ex’d’ suitable for gas group-IIA.7.4 For pressurised electrical equipment installed in hazardous area.7. Motors for hazardous area application.2 4. 6. all electrical equipment associated with fired heaters in process units shall. the following requirements for electrical equipment shall be followed. and metering pumps handling flammable material shall be flameproof type Ex’d’ irrespective of the area being classified as Zone-2 or Zone-1.10 4. Process units having different types of gas groups like IIA/IIB/IIC or different area classification like Zone-1 or Zone-2 or safe shall have electrical equipment to meet all gas groups / area classification to facilitate installation and minimum spare inventory and uniformity.9 4.0 5.7 4. However in case CMRI test certificate is not available for Ex’e’ type as per IS 6381-2004. Safe conditions shall be ensured under all operating .6 kV motors in hazardous areas shall be either with EX ’d’ or EX ‘p’ enclosure only.7. All electrical equipment for hazardous areas shall be certified by testing authorities like CIMFR. then flameproof type (Ex’d’) suitable for gas group-IIC shall be supplied. as a minimum be suitable for installation in Zone-2 area.6 4.8 4.1 4. IIB.02/0002/A4 Sheet 6 of 43 Revision 0 4. PTB. All electric motors for vertical oil sump pumps shall be flameproof type Ex-d.5 4. mixers.7. IIC irrespective of the area being classified as Zone-1 or Zone-2.ENGINEERING DESIGN GUIDELINES ELECTRICAL 44LK-5100-00/E.3 4.7.4 4. when fed from frequency controller VSD panel shall have enclosure protection flameproof Ex’d ’ irrespective of area classification.1 SYSTEM DESIGN PHILOSOPHY The design of electrical installation shall ensure provision of a safe and reliable supply of electricity at all times.7.7. pump house associated with storage areas and within the loading / unloading gantries shall be flameproof type Ex’d’. irrespective of zone classification of zone 1 or zone 2. ENGINEERING DESIGN GUIDELINES ELECTRICAL 44LK-5100-00/E. the quality or the quantity of product. data logging and maintenance of the equipment. 5. operating duty cycle (continuous. For such load reliable source shall be ensured. spares and overload capacities to achieve desired reliability and flexibility requirement.02/0002/A4 Sheet 7 of 43 Revision 0 conditions including those associated with start up and shut down of plant as well as those arising out of failure of electrical equipment. when failing in operation or when failing if called upon. efficiency. power factor. The isolation of part of system of electrical equipment due to either maintenance or shut down shall not compromise safety. critical) etc. All the electrical consumers within the battery limit shall be correctly identified and listed to have complete details of rating. category of supply required (emergency. Required redundancy (based on specific process / operating needs) shall be built in substation which feeds power supply to process unit / important facilities so that in case of tripping of one feeder. the short circuit current shall be kept within limits keeping in view of the market availability of switchgears. emergency / essential or vital / critical loads as per the concepts defined below: 5. Some of the loads which can be identified as emergency / essential load but not essentially limited to following: Electrical loads required for continuous operation of process plants / utility etc. cleaning and maintenance with the care to safety in operation and personnel protection To provide reliability and flexibility of service Adequate provision for future extension and modification Maximum interchangeability of equipment Desired level of operator interface to achieve co-ordinated efficient and failsafe operation.3. Such feeders shall be grouped on a separate bus-section in the respective MCCs. At the same time. While sizing the system necessary consideration shall be given to restrict the system voltage drop within permissible limits during starting of large rated motor or group of motors.2 System shall be designed considering following aspects in general: To facilitate inspection. Electrical loads required for safe shut down of facilities Emergency lighting All communication facilities Fire Alarm System / Fire fighting equipment Level gauge / vessel lamp illumination . will affect the continuity of operation. stand by.3 Load Grouping Electrical consumers shall be classified as 'normal / non-essential. normal. To decide redundancy. standby). Power distribution system shall constitute substations located near load centres as far as practical. Reduced voltage starting (soft starter feature) for motors may be considered as per system requirements. 5.1 'Emergency' or 'essential' loads shall be identified on the criteria that. the unit may not be adversely affected and continuity in operation is achieved. intermittent. 415V PCC/PMCC. if any. UPS supply shall be provided to facilitate uninterrupted supply.6 kV Switchgear.4 5. thereby restoring power supply to the affected section. Hence the non-essential load does not require any special measure such as standby feeder or standby source to safeguard the continuity of service.3. Working & standby load shall be distributed on different bus sections. the bus coupler shall be closed through automatic bus transfer. equipment and / or personnel 5. SYSTEM VOLTAGES Following factors shall be taken into account while selecting the voltage levels: Short circuit level Availability of the switchgear with suitable current rating and short circuit rating. Switchgears (MV. Upon failure of any of the incomer in ‘ON’ due to loss of power supply.ENGINEERING DESIGN GUIDELINES ELECTRICAL 5. For critical loads if any. when failing in operation or when called upon. 5. LV) to be supplied by contractor shall have 2 incomers and 1 no. Buscoupler.3. standards as well as the voltage of existing installations Overall economy for optimum voltage selection. . In case of 6. Non-essential service is a service. Normal operation shall be with both the incomer in ‘ON’ position and bus coupler in ‘OFF’ position. Some of the load which can be identified as critical / vital load but not essentially limited to following: Loads providing control and protection to plant equipment Loads serving critical equipment for safety of plant.3.2 UPS / Battery charging equipment Control room AC equipment 44LK-5100-00/E. Size and location of loads Choice of voltage may also be affected by local regulations. The loads on UPS are PLC / DCS etc. which is neither 'essential' nor 'vital'.02/0002/A4 Sheet 8 of 43 Revision 0 Essential ventilation system for offices / manned areas of other buildings 'Critical' or 'vital' loads shall be identified on the criteria that. Once the power supply is resumed / fault is cleared on affected incomer. MCC shall be provided with 2 incomers and one no. closing of the incomer and tripping of bus coupler shall be done manually. jeopardize life or cause a major damage to the installation. can cause an unsafe condition of the installation. Existing available voltage levels in the refinery. Critical drives if any. Utilisation voltages of various equipment Provision of future extension. bus-coupler. with momentary paralleling of two incomers through synchro check relay.5 All the components of electrical system shall be designed to take into account following: Maximum demand under most severe operating conditions Intermittent service loads. shall be provided with DC motors. 20 % spare for future addition. 5 % Max. 50Hz 240 V AC. 110V DC PMCC/MCC for MV Switchgears and 110V.37KW . AC for any other control supply to be derived from UPS. TPN. 6 Cables from ASB/PDB to Power Points Circuit between LDB and lighting points . SPN. SPN.5 % 3% 3 4 Cables between HV Switchgear and HV motor Maximum Voltage drop upto LT motor terminal during running condition during starting condition 5% 20 % 4. 110V.upto and including 160KW Motors rated below 0. Control supply from UPS for excitation panel. 50 Hz 240 V AC. 1 2 System Element Maximum Permissible Voltage Drop Bus duct / Cable between transformer secondary and switchgear (HV / MV / LV) Cables between PMCC and MCC/PCC or auxiliary switchboard Location of switchboard: Near PMCC Remote 0. 50 Hz 220V DC 240V SPN AC for MCC to be derived from control bus in each vertical section of MCC. 50Hz 110 V SPN for Instrumentation loads 415 V AC. No. 50Hz 415V AC.37KW UPS system AC lighting / Auxiliary boards Normal lighting Telephone system Critical lighting Control supply : : : : : : : : 44LK-5100-00/E. 50Hz 240V AC. 5. 2. AVR.5 % 5% 5. AC for DCS / PLC control supply to be derived from UPS.5 % 0. TP.6 PLANT UTILITY LEVELS: Motors rated above 160 KW Motors rated 0.02/0002/A4 Sheet 9 of 43 Revision 0 6.7 VOLTAGE DROPS: The maximum voltage drops in various sections of the electrical system shall be within the limits stated in the following table: Sr.ENGINEERING DESIGN GUIDELINES ELECTRICAL 5. Fire Alarm system and Paging system. SPN.6 kV TP. Motor fdr 5. & 4 cores 630 – 1 core .8 Sr. – Power fdr & transf. the voltage available at the motor terminals must not be less than 85 % of the rated value during start-up or re acceleration.6/0.8.8. no.8. 5. the resistance value shall be chosen to limit the earth fault current to a value recommended by motor manufacturer for insulation protection and sufficient for selective and reliable operation of earth fault protection system.8.3 5. – 1 sec 5.ACB controlled incomers to MCC/PCC/ASB etc. 415 V switchgear 35 MVA for 1 sec.02/0002/A4 Sheet 10 of 43 Revision 0 5% As per instrumentation requirement. For LT motors. .433kV transformer and the fault contribution from motors) Sizing of high voltage cables shall be based on short circuit withstand capacity in addition to the current capacity. (In case the upper limit of 6. the voltage available at the motor terminals must not be less than 80 % of the rated value during start-up or re-acceleration.Transf.6 kV 300 – 3 core 1000 – 1 core 1 Sec. then if necessary.11 For resistance grounded systems. The .433kV transformer is increased to more than 2000kVA.2 5.1 DESIGN CRITERIA FOR CABLES: Design Criteria Recommended limiting size of multi core cable (mm2) Short circuit withstand time 6. 6.up must be sufficient to ensure positive starting or re acceleration of the motor (even with the motor fully loaded. For HT motors.25 Sec.4 5. 5. the fault level of the 415V switchgear shall be appropriately increased taking into account the impedance of the 6. 6. 5. The voltage available at the motor terminals during start . Fdr 0. 3½. To PMCC – 1 Sec.6 Unearthed XLPE – kV Earthed XLPE 415 V 300 – 3.ENGINEERING DESIGN GUIDELINES ELECTRICAL 7 8 DC supply circuits (Electrical controls) UPS circuits 44LK-5100-00/E.6/0. if required) without causing any damage to the motor.6 kV switchgear .9 Insulation voltage grade Type of cable insulation SHORT CIRCUIT CAPACITIES All the switchgears shall be designed for following fault level withstand capacity.457 MVA for 3 secs.10 INSULATION SYSTEM Following factors shall be considered while designing the Insulation of Electrical system System voltage System grounding Switching over voltages Lightning surges For MV motors (VCB controlled) surge arresters shall be provided. Relays shall support features like remote relay parameterisation. Bare minimum Protection devices for power distribution system shall be as indicated below.1 5.12.3 . bus couplers. Restricted earth fault protection shall be provided for transformer secondary.1. incomers.12. however EPCC shall provide any other necessary protection relays required for complete protection of system: - 5.12 PROTECTION AND METERING SCHEMES Selection and co ordination of Protection and metering system shall be such as to ensure: 5.12. 100% redundancy shall be provided for communication. sensitive and reliable protection of equipment against damage due to internal or external faults or atmosphere discharge. 5. In general.12. tie feeders etc so that the protection zone gets extended upto the last breaker / zone for which differential protection is provided.02/0002/A4 Sheet 11 of 43 Revision 0 value of limited earth fault current shall not exceed 100 % of transformer full load current.ENGINEERING DESIGN GUIDELINES ELECTRICAL 44LK-5100-00/E. Protective relays / releases shall be numerical and communicable type with open protocol (such as modbus) of latest version suitable to communicate with MMI and ECS.1 Selective.1. disturbance recorder etc. Uninterrupted operation of healthy system Personnel & plant safety Important plant feeders such as source feeders shall be provided with differential protection.2 5.1. fast acting relays (with time delays if required) shall be used and all fault tripping shall be done through high speed tripping relays. The CT arrangement / locations provided for differential protection shall be such that overlapping zones are formed for differential protections provided for MV feeders. comprehensive unit providing protection. winding ≥ 6. 46.433 kV) Yes Motor Feeder MV MV Outgoing Feeder LV PCC/ PMCC Yes MV Incomer LV PCC/ PMCC 51 IDMTL over-current relay 51N IDMTL earth-fault relay 51 G backup E/F relay (secondary neutral) Motor protection relay with locked rotor feature 50.ENGINEERING DESIGN GUIDELINES ELECTRICAL 44LK-5100-00/E. . 2 under-voltage relay with timer Yes (11) Yes Yes (20) Yes Yes (20) Yes - NA NA NA Yes (14) No No Yes Yes Yes No No No NA - Yes (4) Yes (4) All relays shall be with non-volatile memory.02/0002/A4 Sheet 12 of 43 Revision 0 Type of Relay Transformer Feeder (HV side) (L. 64 R instantaneous restricted earth-fault relay (secondary side) 50 instantaneous over-current relay 50N instantaneous earth-fault relay 87 differential protection relay Yes - Yes Yes Yes Yes No - Yes Yes Yes Yes Yes No - NA No No No No No Yes NA Yes (7) No No Yes Yes - NA No Yes (21) Yes (21) Yes Yes Yes Yes - NA NA NA No No No No No No Yes (1) No Yes (2) No Yes No (13) 86 tripping relay Yes Yes Yes (14) 95 trip circuit supervision relay 63 Auxiliary relay (transformer) 27.V. 50N.V.6 kV) (L. 50L/R etc. winding ≤ 0. 49. Special protection for any feeder such as differential. Lock out relay shall be conventional type with hand reset facility.5 / 5 sec). MV breaker controlled motor feeders or contactor feeders with DC control supply. 86 relay shall be part of the Numerical relay and shall have provision for hand reset. It shall be possible to set / operate the relay from the front facia. directional distance power relays etc. 12. 10. One for electrical tripping and other for process tripping and each relay shall be hand reset type only. 14.02/0002/A4 Sheet 13 of 43 Revision 0 metering. Separate Electromechanical relay shall not be provided. U/V tripping of motors in 6. 15. Value of stabilising resistor for Differential relay (CAG 14) to be selected suitably based on fault level 18. DC supply supervision relay (80) shall be provided for each incoming DC supply to the switchboard 13. The breaker contacts for critical logic (upstream / downstream tripping. NA For motor feeders rated 75 kW and above. Instantaneous overcurrent 50 and earth fault 50 N shall be provided only for transformer with delta primary. 3. 8. 2. Notes 1. 11. 5. restricted earth fault.6 kV system shall be based on critical / noncritical selection (0. 6. NA The bus tie feeder in switchboards shall be provided with 51. Bus differential protection shall have overlapping zones. control and communication with MMI. 51N. 4. 86 and 95 relays. NA 16. One no.ENGINEERING DESIGN GUIDELINES ELECTRICAL 44LK-5100-00/E. For motors rated 1000 kW and above NA For switchgears where auto transfer feature is provided. For transformers rated 5 MVA and above and shall include primary & secondary busduct / cables also. 7. PT fuse failure relays in MV / LV panels and Busbar differential supervision relay (VTX-31) to be installed 17. One set of bus differential relays (87B) and bus wire supervision relay (95 B) for each bus section shall be provided for MV switchboards.) shall be provided directly from breaker auxiliary contacts and not from auxiliary contactors. Two sets of 86 relays shall be considered for each HT motor feeder. Bus differential protection IN / OUT selector switch shall be provided on panel with indication. . 9. shall also be through numerical relay having serial port for monitoring. changeover etc. The feeders shall be provided with timers for delayed tripping on bus under voltage while the under voltage relay shall be common for the bus. power. Transformer auxiliary protection: Buchholz.9kV Transf.ENGINEERING DESIGN GUIDELINES ELECTRICAL 44LK-5100-00/E.12. Bus A V Hz MW M W H X Hour Run - MVAR MVAH MVA PF X - - X X - - - X X X X X - X X X X X X - - X X - - - - X X X - - - X - - - - - 6.6kV Swgr Bus Tie 6. voltage. Memory / History of the Numerical relay shall not get erased due to loss of auxiliary supply of the relay. OT.6/0.12. Metering instruments shall be provided to keep record of power consumption and supervision of all concerned parameters like current. OLTC alarm / trips to be provided. WT. Preferably similar make of relays to be installed in one particular substation.1.4 Capacitor Banks shall be provided with following protection: 5. Feeder Type 110/6. 20. MOG.T. all the metering shall be a part of comprehensive metering and protection relay unit.6kV P.6kV Capacitor PMCC/MCC Incomer X X X X - X X (kW - X - - - - .6kV Swgr Incomer 6.6KV Plant Feeder 6.02/0002/A4 Sheet 14 of 43 Revision 0 19.6kV Motor Feeder X - - - X (kW h) X - - - - 6. Except voltmeter and ammeter. frequency. For transformer secondary side. Feeder 6. 5. 21.433kV Transformer 6.2 IDMTL overcurrent with high set element for protection against short circuits Instantaneous earth fault Neutral phase displacement Undervoltage Overvoltage Built in fuse for each basic capacitor unit. power factor etc. All the instruments shall be flush mounted. . 3 number CTs shall be connected on three phases with Ammeter Selector Switch for 1 number Ammeter.ENGINEERING DESIGN GUIDELINES ELECTRICAL h) Feeder Type PCC/MCC Bus Tie PMCC Bus P. Above 11 kW Ammeter shall be connected through CT connected on Y phase. For motors rated 37 kW & above. However. Up to 11 kW ammeter shall be directly connected to Y phase. 3 X X X X (kW h) X (kW h) X (kW h) X X X X A V Hz MW M W H Hour Run - 44LK-5100-00/E. analogue type voltmeter and ammeter shall be separately provided. 2. Field ammeters are to be provided for all 3 phase motors Ammeter shall be provided on all motor feeders.02/0002/A4 Sheet 15 of 43 Revision 0 MVAR MVAH MVA - X - - - - - - - - - - - - - - - LV Motor - - - - - - - - - - - - - - - - - - - - All metering shall be a part of comprehensive relay.T ACB Outgoing X X (kW h) X (see note3) PCC/ASB Incomer MCCB/SFU Outgoing (≥ 250 A) LDB Incomer DG Set X X X X (kW) Notes: 1. All numerical relays shall communicate to its data concentrator / bay module / RTU serially on dual redundant RS 485.7 .4 5. User-friendly windows based software shall be provided for interactive display of substation data in multi-window feature. 5. continuously polling. MMI system shall have two distinctive passwords one for viewing of data metering etc. MMI system should be either of Siemens or ABB make and shall be integrated with the existing GFEC MMI system. Signals. Data concentrator/ Bay module shall be interfaced with RTU of integrator’s system on dual redundant RS485. Softwares shall have the capability to display substation single line diagrams. CPU during detail engineering shall not have any commercial implications. fault disturbance record of each relay.6. Data concentrator shall have dual redundant architecture including internal bus and processor for the reliability of data communication. mod bus / proprietary protocol. kV) and LV system (if relay make is different) shall be separate for faster and effective communication for control.13. 5. System configuration shall be latest proven model and upgradable. EPCC / LEPCC contractor shall visit site if required for collecting the details of the existing MMI system for the purpose of integration of the New MMI system with the existing GFEC MMI system. suitable protocol converter shall be supplied as a part of supply of data concentrator/ Bay module.1 DATA CONCENTRATOR / MMI / INTERFACE TO DCS SYSTEM 0ne number laptop shall be provided as engineering workstation. display for electrical system parameters. Suitable switching hardware shall be provided for selection of required data concentrator with click of a mouse from MMI. Existing GFEC MMI system is of ABB make. All softwares shall be written for operating on a common operating system platform plant wide and shall be able to communicate with other/existing system.13. The display shall have electrical system overview and detailed information about its sub system. relay supervision. mod bus protocol.6 5. MMI shall allow minimum of the following functions Feeder status monitoring Data Logging Relay parameterisation Event recording Annunciation View of historical data and generating trends Preparation of maintenance schedule.13 5. relay programming. and second for authorisation for change in relay setting etc. Audio / Visual Alarm annunciation shall be provided alongwith hooter. tripping features.3 Data concentrator for MV switchboard (6.02/0002/A4 Sheet 16 of 43 Revision 0 5. data logging.ENGINEERING DESIGN GUIDELINES ELECTRICAL 44LK-5100-00/E.13.13.13. relay monitoring. daily and monthly data logging. A change of operating platform for MMI.2 5. monitoring and supervising the electrical system. Scan time of Relay LAN shall be less than one second.5 5. In case relays are communicating serially to data concentrator/ Bay module on proprietary protocol. graphic representation and trending of data etc. data as required for MMI/ ECS system serially and through hard wiring as designed elsewhere shall be wired upto RTU panel.13.13. Data not available on relay LAN shall be acquired through hardwired connections to MMI RTU. reports. alarm annunciation. 14 5. intermittent and stand-by: Type of load Continuous Intermittent Stand-by Diversity Factor to be Considered 1.1. Electrical switchgear control Critical lighting Critical DC drives MMI 5.10 5.8 5.15 EMERGENCY POWER SUPPLY The emergency power supply system shall be designed to feed the following types of loads as required: Electrical loads essential for safe shut down Emergency lighting Loads critical for process.13. Each MMI shall also have provision of interface with remote DCS located at centralised place and necessary port RS485 etc. c.13.11 5.13.13. While sizing the transformer following guidelines shall be followed for various types of loads i. independent DC power supply systems shall be provided for following a. Each relay / MMI system shall be time synchronised with GPS. Lighting transformers shall be dry type. marking and identification. Transformer sizing shall be such as to take care of continuous maximum demand.1. b.ENGINEERING DESIGN GUIDELINES ELECTRICAL 5. as required shall be included. plant and personnel safety. d.1 6. 3-phase.1 EQUIPMENT DESIGN PHILOSOPHY TRANSFORMERS The transformers except lighting transformers shall be ONAN.e. 6.3 0.02/0002/A4 Sheet 17 of 43 Revision 0 The system shall be complied with standard IEC 60073 .Basic and safety principles for man-machine interface.0 6. continuous.0 0. DC POWER SUPPLY Unless otherwise specified. oil immersed / Dry type.9 44LK-5100-00/E.1 1) 2) & 3) 6. All hardware and software shall be suitable for substation operation and integration with ECS-RTU and to achieve minimum but not limited to the requirement as defined elsewhere. starting of highest rated induction motor with other load in running condition and minimum 20 % spare capacity for future requirement.2 . double wound type suitable for outdoor installation. The transformer impedances shall be as per Indian standards unless otherwise required.4 6. Bus coupler rating equal to largest incoming circuit breaker rating.15MVA may be considered as a special case by Owner/PMC. 100 % standby transformer shall be provided in substation.50 % of their ONAN rating. distribution transformer from each lot to be selected for type test in addition to routine test For all other requirement refer ESS: 44LK-5100/E.6 kV) All switchgears and associated equipment shall be rated for the rating of transformer /motor being fed from it under any circuit configuration.1 for stand by loads need to be considered for only those loads/drives which are required to be started before switching off of the normal working loads/drives when there is a planned change over to standby system (other standby loads need not be considered for transformer sizing) 2) 3) 6.433 kV) shall be normally limited to 2.1. Power transformers shall be of low losses type. However. However. buscoupler and outgoing feeders of MV switchgear shall be same.2 per unit of rated peak line to earth voltage. if space availability and layout restriction dictates so and is subject to the condition that the overall size of all the related equipments is such that it can be accommodated in the available space and the equipments are rated for corresponding increased fault level and have valid type test certificates corresponding to the increased fault level.1. for 6. breaker and busbar rating of incomers.1. Usually no load & load losses shall be optimised for operation around 40 .2.7 6. 6.6 6. shall be provided in each panel.3 6.8 6. rating and % impedance of each transformer shall be selected to limit the short circuit current to values within the current rating and rupturing capacity of switchgear available and also to ensure the voltage drop within permissible limit.1.5 MVA. Required surge arrestors may be provided for this purpose.0).4 Minimum 25 % spare feeders or one no.2 6.0) The diversity factor of 0. relaxation to maximum rating up to 3. Maximum rating of distribution transformers (6.6/0.2. whereas for power transformers (110 /6.5 6. One no.433kV transformer.2.1. power transformer and one no. The standby loads to intermittent loads which will come into operation only when the working intermittent load fails/trips need not be considered for transformer sizing (Diversity Factor = 0.2.2 MV SWITCHGEAR (6. Rating of Bus coupler shall be suitable for following conditions: Maximum running load on either side of bus section. lighting system unless otherwise specified.3 In general. .1. In case of MV vacuum circuit breaker.6/ 0.1 6. Should not be less than bus bar current rating. 6.02/0002/A4 Sheet 18 of 43 Revision 0 The loads which are required to be operated only during start-up of the plant and which are not required to be operated during normal operation of the plant need not be considered for transformer sizing (Diversity Factor = 0.ENGINEERING DESIGN GUIDELINES ELECTRICAL 1) 44LK-5100-00/E. of each rating and type. whichever is more.9 kV) rating shall be limited to 30 MVA.02/004. adequate provision shall be made for motor switching to limit the over voltage to 2. 5 44LK-5100-00/E.3.10 6.3 6. Numerical relays in 6.3 6.3. max. welding receptacles may be looped from single feeder.9 9. for feeders rated 630A & above.13 . 2 nos.6 6.3.5 6. For tie feeders.2. MV switchgears shall be supplied with necessary earthing trollies / earthing rods / breaker lifting trollies.3. Service breaking capacities (Ics) for all breakers and MCCBs shall be equal to or higher than the maximum fault level at the point of installation.8 6.3.3. LV SWITCHGEAR (PMCC / PCC / MCC / MLDB / ASB) Switchgears shall have rating at least equal to maximum demand under any circuit configuration and provision for 25 % future requirement Minimum 25 % spare feeders or one no.6 KV switchgear shall be suitable for communication with ECS/MMI/DCS using IEC 61850 protocol.7 6.3.2. Electrical & mechanical interlock (castle key) shall be provided between Incomers & bus coupler.7 6. MLDBs & ASBs. The incoming / tie feeders shall be with heavy-duty type load break switches / ACB suitable for key interlocks. All loads rated 22 kW and above shall be equipped with core balance CT and earth leakage relay.3.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6.3. whichever is more.1 6. irrespective of their ratings shall be provided with ammeters. receiving end circuit breaker shall have ON / OFF control and indicating lamps for sending end circuit breaker with selective closing of secondary end breaker. All motor feeders shall be provided with IEC type 2 co-ordination. Motors rated above 55 kW shall be breaker controlled and shall be fed from PMCC.4 6. All loads rated less than 22 KW shall be provided with ELCBs.2.3.3.12 6. Motor Control Centres with two breaker incomers and breaker bus coupler shall be provided with manual change over scheme. All the switchgear components shall be designed to withstand maximum expected short circuit level for a minimum time of 1 second. However. In case of MCCs.6 6.9 6.10 6.2. Electrical running loads shall be uniformly distributed on each bus and it shall be ensured that running and standby loads are fed from two different bus sections. In case of PCC / PMCC all outgoing feeders shall be minimum 800A ACBs. fuse switch units shall be provided. For all other requirement refer ESS: 44LK-5100/E. Separate feeders shall be provided in the switchboard for each load / motor. The maximum rating of incomers / bus couplers of motor control centres / auxiliary switchboards / power distribution boards / lighting distribution boards shall be preferably limited to 800A. Electrical running loads shall be uniformly distributed on each bus and it shall be ensured that running and standby loads are fed from two different bus sections.11 6. of each rating and type.3.02/0002/A4 Sheet 19 of 43 Revision 0 The rating of Circuit breakers /contactors used in Motor feeder shall be at least 125% of the maximum continuous motor rating.2 6.8 6.02/006. All emergency / critical drives.2. ACBs shall be provided and that below and including 400A.3. shall be provided in each panel. Numerical relays in 415V PCC / PMCC / MCC / MLDB / ASB shall be suitable for communication with ECS/MMI/DCS using IEC 61850 protocol 6.2. direction of rotation.9 6. shall be started through variable speed drive system having soft start feature Starting current of motors rated upto 75 kW shall be limited to 600% (including +ve tolerance) of normal current.5 MW shall be limited to 500 % (inclusive of + tolerance). 6.6kV motors. The terminal box of MV motor shall be designed to withstand the specified short circuit current for 0.8 6.02/002 & ESS: 44LK-5100/E.4.2 6.02/0002/A4 Sheet 20 of 43 Revision 0 For all other requirement refer ESS: 44LK-5100/E.5 MW unless otherwise required by process. Motors shall be totally enclosed fan cooled suitable for outdoor application.14 44LK-5100-00/E. mounting type.7 6. starting torque requirements etc. Generally. Starting current of motor rated more than 75 KW and upto 160 kW shall be as per IS-12615-2004. three phase squirrel cage induction motors designed for direct on line starting shall be used. Vertical motors shall have thrust bearings suitable for the load imposed by the driven machinery. Dual dial type temperature indicator without contacts for bearing also shall be provided for all 6.4 6. indoor/outdoor. The type of enclosure for motors (i. industrial / increased safety/ flameproof) shall be adequate for the application and area in which it is to be used. The mechanical parameters such as duty. shall be designed for continuous duty with rated load. Generally. All 6.5 MW & 7.02/003. starting current limitation or method of starting):Starting current of MV motors rated upto 2. 6.4.1 6.10 - .4. except for application such as crane.4. For hazardous area application motors with variable speed drive system shall be Ex ‘ d ’ type.4 6.3 MOTORS In general. Motors with sleeve bearings may require proximity probes to measure shaft vibration adjacent and relative to the bearings. shall be adequate for the application. hoist. turbine / engine starting.4.3.4. duplex RTDs for bearing temperature detection. Sleeve or anti friction type bearings shall be used.6 6. A separate neutral terminal box shall be provided for making star connection and it shall be adequately sized to accommodate the current transformers for differential protection.4.5 6. All motors operating on VSDs shall have embedded temperature detectors / thermistors for winding with thermistor relay which will trip the motor in case the temperature of winding exceeds the permissible limits. Flameproof motors operating on variable speed drive system shall have CMRI or equivalent authority certifying the suitability of drive motor with VSDs.4. These jackscrews along with the plate are required for moving the motor during alignment.g.5 MW shall be started through Soft starter and motor rated above 7. All the motors shall have class ‘ F ’ insulation with temperature rise limited to class ‘B’. Motors shall be capable for 20 % overspeed without danger of mechanical failure.4.25 second without damage.6kV motors shall be provided with 6 nos. all motors. shaft extension.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6. All LV motor including & above 75 KW shall be provided with PTC thermistors. Limiting Conditions for Motor start up (e. Type of motors that require variable speed drive system shall be suitable for variable speed range with temperature rise within limit and also shall be suitable for area classification. When the motors and pumps are mounted on the common base frame jackscrews with plate of suitable size shall be provided on all four sides of base frame. duplex RTDs for winding temperature detection and 2 nos. motors rated between 2.e.4. soft starter.5. Motors of rating above 55 kW shall be provided with space heater.1 6.5.2 6. All motors above 55 kW up to 160 kW and any critical drive shall be controlled from PMCC using ACB.5.16 6. It shall be suitably supported at regular intervals and both busbars and supports shall be adequately sized and clamped to withstand rated short circuit current without permanent deformation.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6.6 kV & LV Bus bars shall be of Copper. One no.4.02/001. Motors shall be rated for starting at 80 % voltage at motor terminals.7 6.02/0002/A4 Sheet 21 of 43 Revision 0 Any assisted type of starting method (e. ensuring proper acceleration of the driven equipment.1 6.5.5 MW rating. shall be subjected to type test.6 6.4. Minimum 10% additional RTD points shall be provided.5 6. Auto transformer etc.6. and also ensures the protective relay operation.4.4. Motors and Transformers). Outdoor motors shall be provided with canopy. 6.12 6.18 6. For all other requirement refer ESS: 44LK-5100/E.4. Bus-duct shall be supplied with bus-bar flexible links for connection at both the ends and expansion joints for every 3m of bus-duct and bus-duct support materials.8 6. 6. The value of the NGR shall be such as to limit the earth fault current to a value. Insulation for these motors shall be designed for 140 % of rated insulation level to take care of any over voltages that might result during changeover.13 6. Openings with cover at suitable locations shall be provided on bus-duct for accessing the bus-bars for maintenance. Earth bus shall run along the full length of bus duct without any break. which does not harm the equipment (Generators. Ammeter shall be provided on the panel for the space heater circuit.14 6.) for MV / LV motors may be considered for regulation / motor drop within limits. Re-acceleration for identified critical motors shall be provided to cover brief interruption up to 5 seconds in normal power supply.2 NEUTRAL GROUNDING RESISTOR (NGR) Neutral grounding resistor shall be housed in a sheet metal enclosure and shall be naturally ventilated.02/007. Winding temperature and bearing temperature alarm and trip shall be provided for all MV motors. Outdoor bus-duct shall be weatherproof to IP-55 and shall be provided with canopy. For all other requirement refer ESS: 44LK-5100/E. All motors rated up to 55 kW shall be controlled from MCC.19 6.5.5.4.5.4.17 6. 6.15 6. The bus insulators shall be of non-hygroscopic and non-inflammable material.3 BUS-DUCT (if Required) MV busduct shall be phase segregated and LV bus duct shall be non-phase segregated type.6 6.6.5.4. motor from each lot for motors more than 1.4.5 6.g. .11 44LK-5100-00/E.4 6. Batteries shall be adequate to meet the requirements as per duty cycle. ageing factor and maintenance factor shall be considered.3 6.2 .8 6. 6.7.8. the charger shall have single module of float cum boost charging unit.1 UNINTERRUPTED POWER SUPPLY (UPS) The UPS shall have duty and ratings of feeders adequate for the application and shall be suitable for indoor use. the charger shall have dual parallel redundant modules of float cum boost charging unit. static switches. All batteries shall be Ni-Cd type.7.3 6.6 BATTERIES While sizing the batteries temperature correction.2 6. facility for bypassing inverter. UPS system shall be sized to take care of the crest factor of the load current.8.7. unless otherwise specified. Isolator shall be provided for battery bank isolation near battery. The rating of the charger shall be adequate to trickle / boost charging of batteries and to feed the DC load requirement with minimum 10 % spare capacity.2 6.8.2 6. For all other requirement refer ESS: 44LK-5100/E. Each UPS unit shall have dual parallel redundant modules. static switch for maintenance and ACDB. design margin. and full rated current (100%) for a minimum duration of 10 seconds. For all other requirement refer ESS: 44LK-5100/E. Each module shall consists of rectifier transformer. facility for manual transfer between inverter supply and bypass line.5 6.3 6.6.9.7.7. set of batteries (for each UPS module).7.8. filter circuit. For all other requirement refer ESS: 44LK-5100/E.02/005. 20 % spare capacity for future requirement.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6.02/0002/A4 Sheet 22 of 43 Revision 0 NGR shall be able to carry at least 10 % of its rated current continuously. back-up time.1 6. type of load and min.1 BATTERY CHARGER For batteries meant for switchgear control. adequate to supply required rated output for half hour. 6. For batteries meant for DC critical lighting. 6.4 44LK-5100-00/E.02/017. Batteries shall be complete with batteries and battery racks.9 6.02/005. 6.4 6. 25% spare outgoing feeders for future use shall be provided in each DCDB for each rating and type of feeder.7 6.5 6.6.9. bypass transformer. rectifier-cum charger. One summary fault contact shall be provided for remote alarm.8. Battery back-up time shall be considered as 2 hours for switchgear control supply battery and 1 hour for DC critical lighting battery.7. inverter.4 6. 5 6. The rating of the largest branch circuit shall not exceed 25% of the system rating. For all other requirement refer ESS: 44LK-5100/E.9 6. PPs & DCDB shall be provided for complete lighting & power distribution adequate for the respective areas of each EPCC/LEPCC contractor.10. Plant lighting circuits shall be single phase (P & N) rated 240 V AC.2 6. of LPs shall be considered based on location / area served and total loading. Redundant outgoing feeders shall be provided in ACDB.9 6.9.9.02/0002/A4 Sheet 23 of 43 Revision 0 Under normal operating conditions.8 6.10 .6 6. Isolation transformer shall be provided wherever necessary in outgoing feeders of ACDB. the inverter shall be operated in synchronised mode with the bypass line and manual transfer forward/ reverse shall be effected without any break. of LPs.10.9.9. For LPs. In case of mains failure.10. 6. Plant lighting circuits shall be fed from dedicated lighting distribution boards installed in a safe area.3 6. 25% spare outgoing feeders for future use shall be provided in each ACDB for each rating and type of feeder. Inverter in turn shall feed the load through the static switch.10.4 LIGHTING.4 6. the battery shall supply the necessary power to the inverter. If the inverter malfunction or get overloaded. Each lighting transformers shall be sized to feed the entire plant normal lighting load with 20 % as a minimum spare capacity.1 6.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6. the rectifier cum charger shall feed the inverter and charge the battery set.10. POWER & DC DISTRIBUTION BOARDS No. Normally.7 6. Fused disconnect switch shall be provided for each outgoing feeder of the UPS and the fuse shall be of fast clearing type.10 6.02/025 6.10. The fuse rating shall be selected to achieve coordination to protect the UPS during short circuit. Plant lighting distribution board shall include 25% spare outgoing circuits.6 6. The overload capacity & current limiting shall be adequate for the application. The UPS rating shall be adequately sized considering 25% spare capacity for future load.5 % shall be planned for feeding the lighting system of the package units.10. Lighting distribution boards fed through 415 / 415 V lighting transformers with off circuit taps +2.9.9.7 6.8 6. Adjacent lighting fittings shall not be fed from the same circuit. the load shall be instantaneously transferred to the bypass line through the static switch.10.9. Two incomers shall be fed from two bus-sections of PMCC and the third incomer shall be fed from Emergency PCC. Lighting distribution board shall have three incomers and two bus-couplers. Normally about 8-10 fittings shall be wired in each circuit.3 44LK-5100-00/E.10.5 6. Each circuit shall be rated to 16A but not loaded more than 8 A. Harmonic filters if required shall be considered at input side.10. Three separate source supply shall be provided to UPS Incomers. incomer shall be provided with MCB and outgoings shall be with MCBs + ELCBs for control and protection of lighting circuits. Deleted No. A minimum of 25% of MCBs of each board shall be left as spares. 12. Two numbers of stop push buttons shall be provided for the motors.13 6.11.7 6.02/001.11.11. selector switches. In Auto mode switching shall be controlled through photocell. Lighting control scheme shall also be designed to trip the entire lighting system in case of air raid warning.2 6. In addition it shall be possible to switch ON/ OFF entire lighting from ECS and local switchboard.11. For all other requirement refer ESS: 44LK-5100/E.02/012 and 44LK-5100/E. Control stations shall be provided for each motor in the field. which are critical.11.5 6. low noise level etc. which are installed at elevated platforms. System shall be highly reliable. requirement refer ESS: 44LK-5100/E. heater etc. LCS for all emergency / critical drives shall be provided with ammeters.3 . efficient and shall provide high power factor. Local control station shall be provided with ammeter for motors rated 15 kW & above.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6. ammeters. Lube oil pumps. lamps etc.14 6.10.12.02/010 and ESS: 44LK- 6.12.2 LOCAL CONTROL STATIONS (LCS) The local control stations shall be of Die cast Aluminium.10. One of the push buttons shall be installed at ground level and the other near the motor. low harmonic distortion.11.10.1 6. shall be based on the functional requirements of the control scheme and the type of equipment. Auxiliary relays as required for remote switching ON / OFF of lighting system shall be included in lighting distribution board.11. Push button shall be shrouded type. If the application calls for a continuous speed variation over a certain range and requires automatic control/change/adjustment of speed through a feedback control system (or open loop control system). 6.11. All outdoor control stations shall be provided with FRP canopy. System shall be provided with complete by pass circuit to ensure the power supply reliability in case of VSD failure. corrosion resistant etc.02/0002/A4 Sheet 24 of 43 Revision 0 Plant lighting circuits (excluding level gauge lighting) for open to sky areas shall be designed for auto/manual switching.12 6.9 6. For all other 5100/E. The type and number of switchgear components such as push buttons.8 6.3 6. shall be provided with ammeter irrespective of motor rating. Enclosure of the control station shall be suitable for site conditions such as weather proof. Stop push button shall be of stay put type.11 6.11 44LK-5100-00/E.11. dust proof.02/013 6. push button type emergency push button station shall be provided near transformers to trip the transformer feeder in case of emergency. however it can be of momentary type in case of drives such as lube oil pump etc.12 6. Weatherproof.10.1 VARIABLE SPEED DRIVES (VSD) Microprocessor based variable speed drive shall be communicable type and shall be able to communicate with MMI / ECS / DCS.4 6. such as cooling tower fan etc.6 6. flame proof. Local control station for aux. motor insulation. For MV motor drives soft starter can be connected to neutral side of motor.12. Soft starter shall be as per standards IEC 34/ BS 4999 / IS 325 / BS 5000. The system shall be suitably designed with due care for long length of cables. For all other requirements refer ESS : 44LK-5100/E.02/0002/A4 Sheet 25 of 43 Revision 0 The system shall be suitable for load characteristics.13.8 6. In case the cable lengths from VSD to motors are very much on higher side.13. ammeter. chokes.12. For all other requirement refer ESS: 44LK-5100/E.5 6.12. For the same.13 6. VSDs shall be of ABB or Siemens make only.6 6.13. Drive shall be able to accelerate the load over the full speed range (0 – 100 %) with incoming line voltage regulation of 10 %.12. Required local control equipment shall have start. The soft starters shall be so designed that the minimum possible supply voltage drop shall occur keeping in mind the accelerating torque requirement of the drive motor & the load.5 6.14 6. 6.13. output filters.9 6. For LV motor dives. to full rated speed.13. stop speed raise and lower push buttons.12. cable voltage grades etc.6 6. The system shall be designed for 150 % over current withstand for 1 minute. The EPCC contractor shall super impose the motor torque Vs speed curve at reduced voltage (to motor terminals at starting) on torque Vs speed characteristics of the driven equipment to confirm correct operation i.1 CABLES (MV / LV) Cables shall be sized considering the following factors. acceleration to rated speed. Soft starters shall be of ABB or Siemens make only.13.02/031 6.4 6.7 6. The EPCC contractor shall also calculate acceleration time at reduced voltage (based on these Torque Vs speed curves) required for accelerating the drive.3 6. continuous speed control and shall be with soft start feature. This acceleration time shall be sufficiently less than the hot withstand time of the motor. .ENGINEERING DESIGN GUIDELINES ELECTRICAL 6. then suitable number of output reactors shall be provided as well as higher rating of VSD shall be selected.14. The VSD panel shall be selected for location in the clean air conditioned room preferably in the sub-station / MCC room.4 44LK-5100-00/E. speed indicator. phase segregated terminal box shall be provided for the neutral side of the motor. soft starter shall be connected to line side of the motor.2 SOFT STARTERS The soft starters shall be solid state microprocessor control type with self torque adjustment (during controlled start) feature with bypass contactor.1 6. The VSD panels to be supplied shall be of proven model.02/065. The system shall be equipped with an automatic restart facility with preset time within 0 – 15 seconds which will restart the system in case of voltage dip over 20 % or power interruptions less than 4 seconds and recovery of voltage to 95 % with a facility to block the automatic restart.13. ON/OFF/READY status selector switches as required and shall be installed near the motor.e.12. Soft starter shall be designed with starting current limited to 350 % to 400 % (However EPCC contractor shall ensure that this reduced starting voltage is suitable to develop necessary starting torque requirement of the respective motor) .7 6. stranded copper conductor with XLPE insulation.5 sq. All LV power cables shall be with stranded aluminium / copper conductor with XLPE insulation.14.5 sq.12 6.6 6. In case of difficulty in connecting the cables to instrument or relay terminals.2 6. grouping and proximity of cables with each other. All power and control cables shall be in continuous lengths (except for very long feeders) without any joints. Control cables shall be twisted pair or shielded wherever electro-magnetic / electrostatic interference is anticipated.mm Cu conductor.14. mm.5 sq.14 .14.6 kV cables shall be unearthed grade.ENGINEERING DESIGN GUIDELINES ELECTRICAL Maximum continuous load current Voltage drop System voltage Laying conditions 44LK-5100-00/E. conductor screen. control. All control cables shall have 20 % spare cores. Cable outer sheath should have the cable size embossed.14. Power cables with conductor size upto and including 16 sq mm shall be with copper conductor. insulation screen and construction as per IS 7098.14. PVC sheathed armoured and construction as per IS 1554/IS 7098. shall be taken into account) Short circuit withstand criteria as per Cl.02/0001/A4.14.mm.02/008 6.14. All MV power cables shall be made of stranded aluminium or copper conductor with dry cured XLPE insulation. 6. PVC sheath.7 6. with proper colour coding.14. 6. shall be aluminium or copper conductor as indicated in Design basis 44LK5100-00/E. For all other requirement refer ESS: 44LK-5100/E.11 6. minimum 1.14. thermal resistivity of soil etc. For all LPs / PPs incoming power supply cable shall be 4 core of required cross section.4 6.13 6.14.10 6.02/0002/A4 Sheet 26 of 43 Revision 0 (Derating due to ambient air temperature. All control cables shall be with 2. signal cables shall be FRLS PVC outer sheath.8 6.mm Cu.8 – design criteria for cables Transformer cables shall be sized to continuously carry transformer full load current. PVC sheathed armoured.5 6.14. data. For lighting inside the building. PVC insulated wire shall be used in conduit system (for circuit and point wiring). All LV power cables shall be 3 core / 3 1/2 core / 4 core with stranded aluminium / copper conductor with XLPE insulation and construction as per IS 1554. All cables shall be armoured and shall have extruded inner and outer sheath Cables connected in parallel shall be of the same type. conductor size above 16 sq. ground temperature.9 6. Cables for Fire alarm system and DC lighting shall be FRLS cables. Cable joints in hazardous areas shall not be permitted. cross section and terminations. All cores shall be identified with numerical core numbers printed on core instead of colours.14. minimum cross section may be reduced to 1.14. 5.3 All power. armour and construction as per IS 1554. The cables used for lighting and wires in conduits shall have appropriate junction boxes with adequately sized terminals. 70 kg concentrated load at centre span shall be considered. For tray system design. store. in addition to self load and wind forces. decorative.16 6.2 CABLE TRAYS 44LK-5100-00/E.15. Bends. droppers etc.02/0002/A4 Sheet 27 of 43 Revision 0 Cable trays shall be run in either cable trenches / on overhead cable rack or along the pipe rack to suit the site conditions. compressor room etc.room.15.15. administrative building.16. : 2 x 36 W fluorescent mirror optic. 2 x 36 W fluorescent industrial.3 D. following guidelines for design shall be considered. However.1 6.2 6.15. 1 x 250W / 400W HPMV medium bay or high bay 6. 6. crosses. All structural steel design shall be as per Indian Standards. shall have the required bending radii as recommended by the manufacturer with 10% allowance for various cable sizes with a minimum of 300 mm.15. with mounting height more than 6 meters . alternative / different type may also be used depending upon application where the fittings are to be installed.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6.1 6.6 In addition to this. workshop MCC room. Separate cable trays shall be selected for:MV cables LV power cable LV control cable Instrumentation cables/communication cable Cable trays shall be sized considering single layer of cables. All cable trays and accessories shall be FRP/GI.4 The trays shall not show deflection / bend / deformation after laying of cables. Indoor areas Control room.3 6.15 6. tees. All ballasts shall be with copper winding and capacitor for power factor improvement (to 0. reducers.G. LIGHTING EQUIPMENT Lighting fittings shall be of energy efficient type.15.5 6. Support span Cable load for • • • • 150 mm wide cable tray 300 mm wide cable tray 600 mm wide cable tray 750 mm wide cable tray : : : : 30 kg/m 60 kg/m 90 kg/m 120 kg/m : 2000 mm 6.16.16. Generally following types of fittings shall be used for the application mentioned. security office canteen Sub-station.95) shall be provided with fixtures as applicable. Stainless steel (316) Painting . Reflector . Aviation warning lights shall be installed in accordance with the recommendation by the International Airport Authority of India. etc.16. Keeping in view the re strike time lag and to avoid complete darkness in case of a voltage dip/black out condition necessary incandescent lamps may be judiciously distributed throughout the plant area.7 6. Low pressure / High pressure sodium vapour lamps shall not be installed in hazardous areas.16.16.ENGINEERING DESIGN GUIDELINES ELECTRICAL Outdoor areas Platforms. skids.mirror finished. manufacturer’s standard material of construction is acceptable.10 6.16. weatherproof aviation warning light shall be used for chimneys. The material of construction shall be same as mentioned in clause 6. heavy duty. HPMV lighting fittings / Fluorescent lighting fittings : HPMV & MLL lamps shall generally be used for outdoor plant lighting. pump bays. Control gear for well glass and medium bay / high bay fittings shall be separately fitted in the control gearbox where it is not possible to have integral control gear.5m is possible Transformer bay pump bays. where mounting height upto 3 m to 3. The material of construction shall be as follows :Body – FRP in safe areas & Die cast Aluminium in Hazardous areas. non-corrosive atmosphere or pressurisation is maintained.Epoxy painting.12 .Stainless steel (316) Guard . Floodlight fittings on lattice type structure/high masts shall be provided for illumination of tank farm / general area. Fittings to be installed in the hazardous area shall be suitable for the zone and CMRI certified with CCE approval. etc.8 6.9 6.16. 6. otherwise the material mentioned above shall be applicable. The lamp fittings shall consist of a double lamp unit with automatic switchover to the stand-by lamp upon failure of the operating one.Aluminium stainless steel/chromium plated steel .6 6. All fittings to be installed outdoors shall have ingress protection of IP 55 minimum and shall be weatherproof and have a guard.16. Hardware . LED type.16.10 .EPDM or neoprene with u/v resistant and corrosion resistant properties.16.4 : 44LK-5100-00/E. Gasket . 6. tank farm. switchyard. All chemical handling facilities shall be provided with chemical resistant fixtures.16.5 6. Fluorescent lamps shall be used for indoor lighting for non process building and control room.11 Fittings for indoor installation where clean.02/0002/A4 Sheet 28 of 43 Revision 0 1 x 125 W HPMV well glass for safe areas and HPMV lighting fittings for hazardous areas.16. Safe area street and area lighting may employ sodium vapour lamps. 6. 5 6.19.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6. These receptacles shall be provided at selected locations in the plant. 240V. Welding receptacles shall be provided at suitable locations to make sure the receptacle is accessible from any point of the process area with a trailing cable of 30 meters length. single phase.1 6.02/058 PUBLIC ADDRESS (PA) SYSTEM PA system shall meet the requirements of plant operations.20. near static/rotary equipment with a trailing cable of 15 meters length.17.20 6. but the temperature rise shall be limited to a temperature equivalent to class B. Junction boxes installed in classified hazardous area shall be explosion proof Ex’d’ only irrespective of area classification.17. the motor shall be protected. For all other requirement refer ESS : 44LK-5100/E. corrosion resistant etc. JBs shall be provided with earthing stud.02/0002/A4 Sheet 29 of 43 Revision 0 The Junction boxes/Telephone Tag boxes shall be FRP construction with IP 55 degree of protection suitable for installation in classified areas. microphone etc. limit switches etc.20.2 Microprocessor based central exchange. Anti-condensation heater shall be provided for the actuator. master station with external loudspeaker.4 6. However for hazardous areas 240/24V transformer shall be provided within socket to supply 24V to the portable equipment. blowers etc to provide power for portable equipment. dust proof.1 6.18.19 6. The MOV shall be designed to start with 75% of the motor terminal voltage.2 6. three pin sockets shall be provided at suitable locations to make sure that the receptacle is accessible from any manholes of the equipment. local/remote selector switch.18. wall mounted call stations suitable for area classification with horn type loudspeaker. Necessary interlocks and earthing facilities shall be provided as per safety requirements. flame proof. ACTUATORS FOR MOTOR OPERATED VALVE MOVs shall be provided with an integral control box consisting of starter. The power supply for the control circuit shall be AC . hazardous areas. The welding receptacle shall be rated for 63A.17 6.1 6. 415V. The motor insulation class shall be class F. CONVENIENCE / WELDING RECEPTACLES Enclosure of the convenience receptacle shall be suitable for site conditions such as weather proof. torque switches. 3 phase and shall have a scraping earth. 20A. MOV actuators shall be of Rotork make only. It shall consist of: 6. The mechanical design shall be such that in case of torque or limit switch failure.3 6.19. 415V.18. 3 phase receptacle (with scraping earth) shall be provided at suitable location near major equipment like compressors.3 6.19. Outdoor receptacles shall be provided with FRP canopies.18 6. & Desk type call stations alongwith external loudspeaker for installation in buildings.1 JUNCTION BOXES 44LK-5100-00/E. 63A.18. start/stop switches or push buttons. It shall be suitable for terminating or looping armoured signal/power cables. It shall be suitable for wall/column/structure/ceiling mounting. .2 6.2 6.18. 22. The equipment for outdoor shall be weatherproof type conforming to IP 55 degree of protection & shall be provided with canopy. Page & Party system shall comprise of one channel for paging & one channel for party talk. Page & Party in each zone.22.22. substations etc. This mode shall be used for actual conversation.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6.23 6.1 6.22.11 6. gas group & temperature class. For all other requirement refer ESS: 44LK-5100/E. Solid state components shall be used throughout & assembled in plug-in type modules.22.22.3 . For all other requirement refer ESS : 44LK-5100/E. Paging system shall have battery backup for 8 hours in case of power failure.1 44LK-5100-00/E. While paging. Separate UPS with batteries shall be provided for each exchange The design of the system shall be such as to provide two channel communication i.7 6. Equipment shall be made tamper proof by use of non standard screws. conversation shall not be heard over the loud speaker but it shall be carried out on the handsets. substations.02/062 TELEPHONE SYSTEM The process plant.2 6. administration building & other nonprocess/plant buildings etc.23. All equipment & accessories shall be given tropical protection against fungus. For classified hazardous areas flameproof equipment shall be provided duly certified by recognised certifying authority for the area of installation.2 6.8 6.22.22. control rooms. impact resistant.4 6. shall be provided with sophisticated microprocessor based intercom telephone system to facilitate intercommunication.22.6 6. The equipment shall be sturdy. it shall automatically mute the loud speaker near the paging handset to eliminate the acoustic feedback.10 6. exchange of information etc.23.9 6. insects & corrosion.02/024 6. Also it shall be possible to have direct communication with the MCS. EPABX system. off the hook switch & pressing the “press to page” switch.22. Paging speakers provided in areas having ambient noise levels shall produce a paging sound level at least 10 db above the anticipated ambient noise level.02/0002/A4 Sheet 30 of 43 Revision 0 Stand alone systems shall be provided for different process units.e.22. dust & damp proof generally conforming to minimum IP 55 degree of protection. rotating beacons shall be installed such a way that that the operator is alerted in the area. It shall be possible to communicate between two field stations without the interference of the MCS / operator. It shall be possible to make a paging call by lifting the handset. System shall also be designed such that it can be integrated to centralised control. A facility to monitor the health of the system including field stations / speaker shall be provided in the system. In the Party mode. Telephones installed in classified hazardous area shall be flameproof type suitable for the area classification.23. The typical area where the provision of rotating beacons are envisaged are compressor house. Acoustic hoods shall be provided for call stations located in high noise areas. which shall be suitable for interfacing with Fire alarm system. The paging message shall get transmitted over all the loud speakers when the paging person speaks in the microphone of the handset. Where it is not possible to achieve the sound level of above 10 dB above the ambient.3 6. Radio Paging system etc.5 6. which can be opened only by means of special keys supplied by the manufacturer. 1. Substation shall be sized to take care of present and future needs and to maintain adequate clearances between equipment for ease of maintenance. battery charger and other hardware.6 7.5 7.1 7. intelligent. control room etc.2 FIRE ALARM SYSTEM 44LK-5100-00/E.1 7.0 7.24. siren. EPABX. The Substation shall be preferably a separate building with RCC roofing and brick walls.1. repeater panel. The Ground floor of the s/s floor shall be suitably raised from adjacent grade level to avoid water ingress. one entry for equipment / normal entry and the second for emergency exit.02/063 6. Space for two adjacent panels for future extension on each side of switchboard shall be maintained. Gas Detection system and HVAC system. FRLS armoured cables shall be used for the system.1 6.3 7. Positive pressure of 2 mm shall be maintained inside the s/s.ENGINEERING DESIGN GUIDELINES ELECTRICAL 6.1.24.7 7. Detectors and Manual call points shall be connected in separate loop. hooter.5 6. System shall be designed to provide necessary audio visual signals at the main control panel with mimic panel and repeater control panel. However system shall be suitable for integration with CCTV. rated for complete fire alarm system operation for failure of power supply for at least 48 hours. smoke/heat detectors.24.6 6.1. It is to be ensured that the inlet air of the pressurised system shall be free from moisture and hazardous mixtures.1. Room housing critical power supply equipment and operators room of large substations located close to process units shall be of blast proof design in case of main control room being of blast proof construction. Battery and charger shall be provided for each panel separately. PA.24.3 6. System shall comprise of individual break glass type manual call points. System shall be stand alone for entire plant area consisting of process unit. The system shall be hooked up with main fire control panel located at fire station control room.24. digital addressable type.24. 7. main panel. Substation building shall be without any columns within the switchgear room to ensure optimum space utilisation. Substation shall have minimum two entries.4 SYSTEM LAYOUTS SUB-STATIONS Layout of substation shall comply with OISD regulations.02/0002/A4 Sheet 31 of 43 Revision 0 Fire Alarm system shall be microprocessor based.4 6. battery.1. All S/S shall be pressurised. TAC regulations and any other applicable statutory rules and regulations.8 .7 7. For all other requirement refer ESS : 44LK-5100/E.24 6.24. IE rules. substation.2 7. The roof shall be given adequate water proofing treatment to ensure that rain water does not seep into the s/s.1.1. 1. . . shall be complying with the requirements of I. UPS battery chargers. soft starters etc.g. earthing rod shall be provided for each Switchgear room floor of substation (except cable cellar). MMI shall be kept in VSD room.ENGINEERING DESIGN GUIDELINES ELECTRICAL 7. The layout of MV & LV switchgear.E. Rubber mats shall meet the latest IS specifications.Round bottom fire buckets filled with clean dry sand. Name and address together with telephone no. breaker lifting trolley each of MV and LV . PDBs. Switchgear room shall be provided with following minimum (but not limited to) equipment : Suitably rated rubber mats in front of panels for their entire length.Adequate no. Normally transformers shall be installed outdoor. variable speed drives. Battery banks shall be located in a separate freely ventilated room in the s/s building along with the necessary exhaust system and water connection. Electronic equipment like UPS / VSDs / excitation panel of synchronous motor shall be installed in a separate Airconditioned room.Battery impedance tester . shall be properly acid/ alkaline resistant / painted with / alkali resistive paint. Transformer yard / bay shall be provided with fencing and gate and shall have fire isolation walls (fire rating commensurate with the extent of fire which could be encountered). Adequate access and lifting / loading / unloading facility shall be provided to bring in or take out switchgear panels.10 7.1. Light fittings in this room shall be chemical resistant and FLP type. systematic and uncluttered cabling in the cable alley. and size of CO2 fire extinguisher and dry chemical powder suitable for dealing with fire.13 . - 7.1.One No. . LPs. Floor of battery room and the walls upto height of 1 m. load shedding and local monitoring / alarm purposes.Earthing truck . . .11 7. .Two Almirahs for each floor of substation (except cable cellar).Adequate furniture (table/chair) shall be provided on each floor of substation (except cable cellar). .Framed single line diagram . relay parameterisation (setting).1.One No. Wall shall be carried upto a height of at least 600 mm above the top of the equipment (e. Minimum 1000 mm clearances shall be provided all around the transformer.Electrically tested rubber gloves kept in dust free MS box with chalk powder.12 7. transformer conservator) level. Fire wall shall extend at least 600 mm beyond the width of transformer and cooling radiators. of nearest doctor should be entered in it.First aid box easily accessible containing full compliments of ointments and medicines for treatment of electrical burns.Rules and TAC recommendations and shall be developed to have neat.1.02/0002/A4 Sheet 32 of 43 Revision 0 Substation shall be equipped with MMI having 1 laptop as per purchaser’s requirements and shall be installed in an air conditioned room in the substation for co-ordination. . In general 230 mm thick RCC wall or 355 mm brick wall shall be considered to provide adequate fire protection.9 44LK-5100-00/E.Framed shock treatment instruction card in English and local language. 1. All cables from main receiving substation to FW pump house shall be directly buried separated from all other cables as per TAC guidelines.2.1. provision shall be made to drain away the oil to OWS system located away through suitable drain pipes of 150 mm or 200 mm in diameter. Fire proofing/painting for all power cables on 3 meter length of cable at motor end and load end in the field and panel end in the substation shall be provided.17 7.1 CABLE LAYOUTS / ROUTING. All entry and exit openings for cables crossing in substation.2 7.02/0002/A4 Sheet 33 of 43 Revision 0 Oil immersed transformers with oil capacity exceeding 2000 litres shall be provided with a soak pit of sufficient capacity to take the whole of the oil of the equipment. Concrete lined trenches shall have suitable drainage arrangement to avoid water collection or these trenches shall be connected to nearest storm water drain. Cabling system for various areas shall be generally as under. Fire barriers shall also be provided below the opening of all MV and LV switchboard in all substations. Cable trenches shall be sized depending upon the number and voltage grade of cables used for different applications. However.1. shall be provided with fire barrier and it shall have minimum three hours rating. In unpaved areas cables may be directly buried in ground. Where oil capacity of transformers exceeds 9000 litres. Pipes laid for mechanical protection shall be sealed at both the ends.3 7.2.ENGINEERING DESIGN GUIDELINES ELECTRICAL 7. For process units RCC lined trenches shall be waterproofed & filled with sand For offsites & utilities areas. 7. as far as possible existing cabling system shall be followed in OSBL areas. All substation / MCC rooms shall be located outside the hazardous area. Trenches in hazardous areas shall be filled up with sand.4 7. At road crossing. Staircases in substation building shall be sufficiently wide so that 2 persons can climb simultaneously. The top of cable trenches before entering the substation shall be maximum 1m above the ground level and also all cutouts shall be properly sealed by a fireproof (4 hr) sealing compound.2.2 7. RCC trenches and directly buried for paved and unpaved areas respectively.15 7.2. - 7. Lighting.14 44LK-5100-00/E.1. communication cables shall be laid directly buried in road berms. control room etc. Concrete lined cable trenches shall be sealed against ingress of liquid and gases.5 .16 7. cables shall be laid through culverts / hume pipes / pre-cast RCC duct banks etc.2. fire alarm. Cable cellar shall be provided with all required fire & safety provisions as per latest OISD guidelines. The communication and fire alarm cables shall be laid in road berm opposite to the berm where street lighting cables are laid. Nitrogen injection fire prevention system shall be provided for all oil – filled transformers having oil content more than 2000 litres or rated above 10MVA. Cable installations shall provide minimum cable bending radii as recommended by cable manufacturer. Underground cable routes shall be designed to avoid close pipe crossings and adjacent runs with underground pipelines.2. strip of adequate size (75 x 8 mm min.14 7. Earthing lead connections from MEL shall be taken by providing earth plates of adequate size to serve a particular group of devices.7m above grade. supports etc. these shall be run in a single layer form in FRP/GI cable trays. cable tray support shall be sized to ensure lowest tray level to be min. Cable trays shall be covered whenever they are running below pipes. Fire protection for cables shall be provided as per IS 12459: code of practice for fire protection of cables. avoiding as much as possible crossings with instrument cable trenches and pipelines and preferably away from restricted areas.9 7. Necessary supports shall be provided for the same. Separate trays shall be provided for AC and DC signal / control circuits. control and communication cables.2 7.3 7. Whenever cables will be required to run above ground. Necessary tees and bends shall be provided to have neat and easily accessible routing. racks and trenches shall be sized to allow for 25% future cables.2.3 7. Above ground cables shall be well supported on cable trays and shall be suitably protected against mechanical damage.I.8 7. The main earthing loop (MEL) shall be G.3.1 EARTHING LAYOUTS Entire earthing system shall be designed as per IEEE 80 / IS 3043 code of practice for earthing.2. For directly buried under ground cables.6 44LK-5100-00/E.E Rules. 2.2. Separate cable trays shall be provided for MV power.02/0002/A4 Sheet 34 of 43 Revision 0 The offered painting and fire barriers shall be tested at site and comply to the requirement defined in the BS: 476 (part – 20) Method of determination of fire resistance of element of construction and IS: 12458 Fire resistance test of fire barriers and UL: 1479 Fire test of through penetration fire barriers.3.7 7. Earthing leads connecting equipment enclosures. Cable trays.ENGINEERING DESIGN GUIDELINES ELECTRICAL 7.2.3.2. OISD standards for earthing shall be strictly adhered to.13 7. Plant cables shall run in either of the two directions formed by main axis.2. to MEL shall be of G.10 7. Further the requirements of I.I.3. Cables running between cable tray and the equipment shall either run through flexible or rigid PVC conduits. at cable joints and where direction of cable trench changes.2.2.11 7. Cable joint pits shall be sand filled. A distance of at least 30 cm between cable and pipe shall be maintained.4 . route markers shall be provided at every 15m interval all along the cable routes.15 7.12 7. LV power. Wherever pipe rack / pipe sleepers are not available for laying of above ground cable trays.2. Cables shall preferably cross underneath buried pipelines Parallel / Duplicate feeder cables shall be laid separately as far as possible 7. strip / wire /unarmoured aluminium cables of adequate size. 7. Routing shall be decided to avoid interference with hot surfaces or places subject to undue fire risk.) This MEL shall also be connected to existing MEL at different locations wherever possible. 3. control stations. steel Pipe racks shall be earthed at every 25 meters.3. - 7.Cable shields and armour .Transformers / Generator neutrals. For L.13 Independent earthing loop for each S/S shall be connected with MEL Earth pit engraved markers shall be provided for each earth pit.Lighting poles & masts .Storage tanks. receptacles junction boxes etc.Fence / gate for transformer . DCS.3. Overall grid resistance shall be less than 1 Ω. Equipment located remote from main earth network. lighting fixtures.Electronic equipments / DCS / PLC etc All utility / process pipelines shall be earthed on entering or leaving the hazardous area.V. Floating roof tank shall have separate earthing at least six places.3. vessels.ENGINEERING DESIGN GUIDELINES ELECTRICAL 7. This shall be kept galvanically isolated from the system and safety earthing. except where conflicting with the requirements of cathodic protection.Cable armour .11 7. may be earthed by means of individual earth conductors and earth electrodes.Steel structures / pipe racks etc.3. Underground earthing strips to be provided with 50 % corrosion allowance. columns and all other process equipment. cable trays. . .10 7. terminal boxes.6 44LK-5100-00/E. For lighting protection value of resistance of 5 Ω shall be desirable but in no case it shall be more than 10 Ω.3. Value of resistance of an earthing system to the general mass of earth shall be as follows For electrical system and equipment a value that ensures operation of the protective device in the electrical circuit but not in excess of 1 Ω. equipment earth loop impedance shall be such as to effect circuit disconnection in a time less than 1 second under solid earth fault conditions taking in to account the manufacturer’s nominal time / current characteristics of protective device.02/0002/A4 Sheet 35 of 43 Revision 0 Number of earth electrodes shall be decided based on the requirements of IE. 7. . Earth continuity shall be ensured across all the flanges in process units & other hazardous areas.5 7.3. PLC and other electronic instruments shall be provided with clean earth as recommended by the manufacturer for safe and nuisance-free operation. motors.9 7.7 7.Any other equipment required to be earthed / bonded . Rules and to stabilise the potential gradient of the MEL & earth to a safe limit. lighting / power panels.8 Earthing shall be provided for following (but not limited to) as a minimum:Metallic non current carrying parts of all electrical apparatus such as switchgears.3.3. . control panels. In addition. .12 7. 5. shall be earthed with a minimum of three earth electrodes equally spaced round the tank Any other tall structures.4. Where equipment is insulated from plant steel work two earthing connections shall be taken to the earthing network or to adjacent earthed steelwork. In hazardous areas.5.4. vessels stacks and premises shall be checked for risk assessment as per IS 2309. Separate lighting protection system shall be provided for tank farm areas considering high mast meeting the requirement of OISD standards and IS.4. Combined resistance shall not exceed 10Ω.5 7. Where equipment is mounted on steel structures and is in direct contact with plant steel work. Where the resistance across a flange connection exceeds 10Ω.5. 7. earth strips. columns. Where lightning protection is found to be necessary. connection such that removal of one connection shall not isolate any other item of equipment.4.1 44LK-5100-00/E.4. jumpers shall be provided.5 7. GI bonding strap shall be fitted across the flange under one of the flange bolts. 7. towers. Selfconducting structures may not be provided with aerial rod and down conductors. strips/wires of adequate size and shape. A dedicated system of an adequate number of electrodes shall be provided.3.7 . Storage tanks above 30m dia.5. STATIC EARTHING AND BONDING Vessels and pipelines. Faraday cage and down conductors shall be of G.4 7.2 7.I.4 7.1 LIGHTNING PROTECTION All structures. Plant steel work shall be connected to the earth network at a minimum of two points.2 7.5 7. no further bonding is necessary. Air terminations.4 7.7 7. columns etc. An independent earthing network shall be provided for lighting protection and this shall be bonded with the main earthing network only at the point of buried earth electrode. and these shall be properly bonded and earthed to system/safety earth to avoid accumulation of charge.6 7.5. the recommendations of the standard shall be strictly followed.14 7. They shall however be connected to the earthing system at minimum two points at the base. which are considered to be likely recipients of lightning strokes by virtue of their height.5.ENGINEERING DESIGN GUIDELINES ELECTRICAL 7. can lead to static charge generation due to friction. All pipelines shall be bonded together and connected to the earth network at the plot boundary and also the boundary between a hazardous and non-hazardous area.3 7.5. relative to surrounding structures shall also be earthed as described above. These electrodes shall be pipe electrodes.6 7. by the process of movement of flow of liquids.02/0002/A4 Sheet 36 of 43 Revision 0 The LSTK Contractor shall carry out earth resistivity measurements at different locations as required.4.3 7.4. storage tanks upto 30m in diameter and the tallest structures and columns shall be directly connected as close to the base as possible to a minimum of two earth electrodes by 32 x 6 GI strip. ring. Necessary earthing pads. Equipment shall normally be bonded to earthing system by bolted. A maintenance factor of 0.2 7.6.5. Area Roads and tank farm Pump house.ENGINEERING DESIGN GUIDELINES ELECTRICAL 7. down conductors and air termination shall be provided. pipe racks. LIGHTING LAYOUTS The lighting layouts shall be designed to meet the illumination levels recommenced in IS 3046. sheds Main operating platforms & access stairs Ordinary platforms Process areas. heat exchangers.8 44LK-5100-00/E. However. cooling tower. Switchgear room Cable cellar Battery room Control room. Minimum illuminations levels as specified below shall be achieved while designing the lighting system.1 7. Lux (minimum) 10 100 60 20 60 60 200 70 150 500 500 500 100 200 300 7.02/0002/A4 Sheet 37 of 43 Revision 0 Where structure of equipment are not electrically continuous or made of poorly conducting material.6. Additions bonding shall be applied to structures as necessary in order that resistance from the highest point to earth does not exceed 10Ω.6.3 Lighting design shall conform to relevant International Codes &Standards. laboratory SRR Rack Room area Console area Ware house Compressor area Office heater. pump bays etc. for dusty areas. IES Hand Book and shall take into consideration the requirements from point of view of safety and ease in operation and maintenance.6 7. maintenance factor as per relevant codes and standards shall be considered. . separators.8 shall be assumed for lighting illumination level calculation for normal areas. Escape route for safe evacuation of operating personnel. wire guard) .6.5 7.9 Generally 15 % of normal lighting load shall be considered for AC emergency load. condensers. where specific safety operations are to be carried out.6. Areas around drives fed by emergency supply.6 Normal & emergency lighting system shall be on 415 / 240 V system.g. Sufficient lighting shall be provided so as to enable plant operators to move safely within the accessible areas of plant and to perform routine operations./ T. armoured cables run along the column/platforms and structures. Barring gears of turbine. Wiring for lighting and convenience outlets in outdoor areas shall be carried out with copper conductor. Recommended areas for AC emergency lighting : Control rooms Fire stations Staircases Platforms with ladder changing directions Strategic locations in process.G / G. To facilitate carrying out of specified operations. The armoured cable shall enter lighting fixture / JB through double compression gland for safe area and through flameproof glands for Ex(d) and Ex(e) equipment.6.4 Generally plant lighting shall be classified as under: Normal lighting Emergency lighting Critical lighting 7. such as Areas near heat exchangers.6.02/0002/A4 Sheet 38 of 43 Revision 0 7. where critical lighting shall be on 220 V DC. Any other specific areas requiring critical lighting .ENGINEERING DESIGN GUIDELINES ELECTRICAL 44LK-5100-00/E.7 Lighting requirements provided during the failure of power supply for normal lighting shall be broadly.6. suitable mechanical protection shall be provided for lighting fixtures (e.6.8 7. Any other specific areas requiring emergency lighting. Recommended areas for critical lighting : Control rooms Main substations D.T room Central fire station Fire water pump house First aid centre Emergency escape route.G. PVC insulated. 7. To gain access and permit ready identification of fire fighting facilities. 7. for safe shutdown of the plant. Where required. For all other requirement refer standard specification doc. Battery room shall have fitting mounted on wall in order to facilitate easy replacement of fused lamps. and all intermediate joints to ensure that terminal chambers and other enclosures are clean. of junction boxes shall be provided for branch connections.6.14 7. Adequate no.6. 9. for Furnace shall be located on ground level and shall be of FLP type and with canopy. Further. All lighting fittings shall be wired using armoured PVC cable of suitable no.6. temperature rise. For buildings with false ceiling. in control rooms and sub-stations is avoided.6.ENGINEERING DESIGN GUIDELINES ELECTRICAL 7.15 7. DC critical lighting shall employ incandescent lamps.13 44LK-5100-00/E. wiring correctly dressed and labelled and no obvious faults are present. noise and vibration.02/0002/A4 Sheet 39 of 43 Revision 0 The lighting installations shall be designed to obviate stroboscopic effect. Substation / cable gallery lighting shall be centrally controlled from push button near main entrance Soot Blower panel. rooms allocated for operating and maintenance personnel etc.7 8.1 .6.18 7. neat routing/layouts.0 INSTALLATION Installation of all electrical equipment shall be carried out with high standard of workmanship.6.6. if any. no. Necessary type and no. of ceiling fan points shall be provided in offices. 2 pole isolation devices shall be used for controlling fixtures in hazardous areas to isolate phase as well neutral. Soot Blower panel shall be Timer controlled and not PLC controlled. Acceptance of the complete electrical installation shall be contingent upon inspection and test results.6.6. Switches controlling the fittings and exhaust fan shall be installed outside the battery room.16 7. Lamp fittings in structures shall be so located that maintenance and lamp changing can be effected without use of ladder or scaffolding.12 7. The lighting fittings shall be situated in such a way that reflection on instruments / VDU etc. 9. After installation the system equipment shall be tested for pre-commissioning test as recommended by the manufacturers & established practises. No joints shall be allowed inside these pull boxes. and clearances/access as per recommendations by the manufacturer.6.19 7.0 FIELD TESTING AND COMMISSIONING Field tests as per the procedures approved by the Owner shall be performed on the electrical equipment before being put into service. if any. 7.20 7. Field tests shall include but not be limited to the following: A visual inspection at both ends of a cable/conduit run. concealed conduit wiring below the false ceiling and surface conduit wiring above false ceiling shall be considered. and BMS panel. of pull boxes shall be used. commissioning tests shall be conducted to prove agreed performance within specified tolerance. joints tight and sound.6. 44LK-5100/E.17 7. of cores and size.11 7. Adequate no.10 7.02/026. 0 Sr. 44LK-5100/E.4 9. no. 9. ELECTRICAL TESTS SHALL INCLUDE : An insulation test for each winding and circuit with a separate test for each core of power circuit. No 1) 2) MAKE OF COMPONENTS Component Circuit Breaker (6. Earth continuity test for all circuits.10 9.12 9.13 10.ENGINEERING DESIGN GUIDELINES ELECTRICAL 9.3 9. all the covers shall be replaced and cover screw (and gaskets.3 9.3. A close visual inspection of all electrical equipment in hazardous area shall be made to ensure that the equipment is both suitable and correctly installed.3.3. For all other requirement refer standard specification doc. if any) checked to be present and tight. Main circuits shall be checked for correct phasing and rotation. After the above tests and inspection are completed.3.3.02/026. All relays must be checked for settings. ECP ( polymer cage) type bearings shall not be provided in motors. A copy of such test reports shall form a part of completion report.2 9.9 9.1 9.3.3.8 9.3.11 9.5 9. Continuity test for all power circuits and windings. Grease tube shall be of MS.3. An earth resistance measurement for each group of electrodes.6 9. and the earthing system as a whole Lighting installation shall be tested for correct illumination levels with the fittings installed. After completion of tests EPCC contractor shall prepare a joint test report for each test carried out on each equipment and shall get signed by PMC/Owner representative. Fittings shall be operated only with their designed size of a lamp or tube.6 kV) Circuit Breaker (LT) : : Make Siemens/ ABB / Jyoti Siemens (3WL) / L&T (UPower) / Schneider (Merlin Gerin Master Pact Imported make) 3) 4) Switch (Incomer) Switches for Motor feeder / Power feeders : : Siemens / L&T / Schneider Siemens / L&T / Schneider 5) Fuses : 1) Power 2) Control : : : HRC link type Siemens / L&T / Schneider HRC link type Siemens / L&T / Schneider Siemens / L&T / Schneider 6) Contactor . All motors except those having sealed prefabricated ball bearings shall be checked for proper lubrication prior to energisation and shall be tested for correct rotation.3.3.3. All protective relays and meters shall be tested and calibrated. Only ECJ / ECM (steel / brass cage) type shall be accepted. Control circuit shall be tested for correct operation under all operating combinations and proved correct before applying power to main circuits.7 9.3. Capacity test shall be carried out on UPS / batteries / battery charger after installation at site.2 44LK-5100-00/E.02/0002/A4 Sheet 40 of 43 Revision 0 After visual inspection. AE Make. Pf Meter – GEC/Simco.GEC / Simco . Siemens / Teknic / L&T. A & V Meters . Elmex make . KWH/KVARH Meter .02/0002/A4 Sheet 41 of 43 Revision 0 Siemens / L&T / Schneider Silkans / Precision / Pragati / Kappa / Prayog / Jyoti Silkans / Precision / Pragati/ Kappa / Prayog / Jyoti. 12) Terminals : a) Power b) Control : : : : : : : : : : : Elmex . ABB /Siemens Siemens / L&T / Jyoti (PLUGGING TYPE) Kaycee Siemens / L&T ABB/Allen Bradley /OEN ABB/Southern Transducers / Rochester (USA) Perfect Controls / Precimeasure Perfect Controls / Precimeasure BHEL / CGL / Easun Reyrolle 13) 14) 15) 16) 17) 18) 19) 20) 21) Relays Auxiliary Contactors Selector switch Timer Interposing relays Transducers WTI OTI Tap Changer Assembly .ENGINEERING DESIGN GUIDELINES ELECTRICAL 7) 8) 9) 10) 11) Overload relays Current transformer Potential transformers Push buttons Meters : : : : : 44LK-5100-00/E. Indoor Type (Up to 33kV) Bus Duct (HV/LV) Medium and High Voltage Heavy Duty Cables Main Lighting & Power Distribution Boards Lighting Panels.02/009 44LK-5100/E. Work Motorized Valve Actuators 3-Phase Alternating Current Generators Upto 1.02/024 44LK-5100/E.C.S) Electrical Installation Electrical Content of Package Unit HV Capacitor Bank AC Variable Speed Drive System. 44LK-5100-00/E.02/007 44LK-5100/E.02/059 44LK-5100/E.02/004 44LK-5100/E.C.02/008 44LK-5100/E.02/027 44LK-5100/E.02/003 44LK-5100/E.02/002 44LK-5100/E.02/006 44LK-5100/E.5MVA For Standby Duty Public Address System Fire Alarm System .02/011 44LK-5100/E.02/062 44LK-5100/E.02/058 44LK-5100/E.02/010 44LK-5100/E.02/025 44LK-5100/E. No.ENGINEERING DESIGN GUIDELINES ELECTRICAL ANNEXURE – I :List of reference standard specifications: Ref. 44LK-5100/E.02/031 44LK-5100/E.P.02/013 44LK-5100/E.02/012 44LK-5100/E.02/035 44LK-5100/E.02/005 44LK-5100/E.02/063 Title Induction Motors L. Lighting Transformers Conduit Installation for Conduits and Fittings Embedded in R.02/032 44LK-5100/E.V.02/029 44LK-5100/E.02/017 44LK-5100/E.02/0002/A4 Sheet 42 of 43 Revision 0 Lighting and DC Distribution panels with MCBs Industrial Local Control Stations Flameproof Local Control Stations Neutral Grounding Resistors Telephone System Static Uninterruptible Power Supply Unit (U.02/001 44LK-5100/E.02/026 44LK-5100/E. Switchgear Motor Control Centres (MCC) Power Transformers Battery & Charger HV Switchboards . 02/070 44LK-5100/E.02/0002/A4 Sheet 43 of 43 Revision 0 ANNEXURE – I :List of reference standard specifications (Contd.02/071 44LK-5100/E. Electrical system for E.02/072 ECS Soft Starter Flameproof distribution panel.) 44LK-5100/E. T.02/067 44LK-5100/E. plugs.ENGINEERING DESIGN GUIDELINES ELECTRICAL 44LK-5100-00/E. Crane High Voltage Synchronous Motors Thyristor Control Panel for Electric Heaters Electrical Heaters . O. lamps and Light fittings for Hazardous locations.02/065 44LK-5100/E. sockets.02/069 44LK-5100/E.02/064 44LK-5100/E.