SUBSTATION LAYOUT, SWITCHING SCHEMES AND GENERAL ARRANGEMENT16.02.2009 (15:45 TO 17:15) MANOJ KUMAR, MANAGER (S/S), MOGA [email protected][email protected] Mob. : 09417215560 General Arrangement A Designer perspective, but fine tuned at site Placement of switchyard Control Room placement Fire fighting pump house placement DG set placement LT station placement (ACDB, DCDB, Battery Bank & Battery Charges Identification of roads & rail tracks Identification of boundary wall and fencing Identification of approach roads Space for colony and other infrastructures Switchyard Layout Single Line Diagram Bus Switching Scheme Normal rating with temperature rise, Short time current rating Rating & insulation levels of the equipments Bay numbering General Arrangement LAYOUT (PLAN & SECTION) OF SWITCHYARD PLANNING ASPECTS: • • • • • Switching scheme to be adopted. Type of Layout (D or I) Details of feeders requirements. Future/anticipated expansion of the substation . Available size of plot . Major factors deciding a layout … Standard factors Electrical clearances Heights of different levels & electric field Shape of land & feeder orientation Bus bar arrangement Type of isolator used Arrangement of lightning protection Location of control room building, FFPH Roads and rail tracks Variable factors General Arrangement Following factors determine the switchyard area Conventional (AIS) OR GIS D Type OR I Type Layout Automation (SAS) OR without Automation . 14 acre (27m bay width) 7969.5 sqm=2.5sqm=1.969 acre (24m bay width) 3504 sqm = 0.865 acre (24m bay width) .GA:.Area occupied by one Dia in D & I Layout 8662. . Jack bus.Layout (Plan & Sections)… Selection of conductor for main bus. Transfer bus. equipment interconnection AAC conductor ACSR conductor AAAC conductor Aluminium pipe Space for a bay (bay width) Phase to phase clearance Phase to earth clearance Section Clearance ….under worst condition . t clearances. .r. insulation levels.Minimum Clearances for Layout (at altitude <1000m above mean sea level)… Voltage Level (Rated) 765 kV 400 kV 220 kV 132 kV Ph-Ph (mm) 7600 4000 2100 1300 Ph-E (mm) 4900 3500 2100 1300 Sectional Clearance (mm) 10300 6500 5000 4000 110 kV 66 kV 33 kV 1100 630 320 1100 630 320 3800 3500 2800 Altitude corrections w. creepage and oil temperature rise of the equipment shall be considered for altitudes more than 1000 m above mean sea level. Design Calculation for Layout … Sag tension calculation & Sag tension Chart w.r. maximum temperature rise etc.t initial static tension. Short circuit force calculation and determination of spacer span as per IEC:865 Direct Stroke Lightning Protection (DSLP) Calculation By Lightning Masts By Overhead earthwires Design of earthing system Touch & step potential control Grid resistance as low as possible Location of fencing . 5m 325 Ligtning Impulse : 1.7m 7.2/50 micro sec Switching Impulse: 250/2500 micro sec .Bay widths & levels… Voltage Level Bay width First Second Level Level Third level BIL kVp SIL kVp 765 kV 38m 14m 8m 27m 15m 11.8m 650 9.6m 4m 16.5m 6m 39m 22m 2100 1550 1550 1050 650 NA NA 400 kV 27/24m 220 kV 18/16m 5.9m 132 kV 12m 4.6m 66 kV 7.2m 1050 10. To understand Single Line diagram & Layout plan drawing… . To understand Layout Section drawing… . 5m NIL NIL 7.5 m ±30 deg ±30 deg 0 deg 0 deg 0 deg 0 deg ±30 deg ±30 deg End Middle End Middle Corner/ 2beams Middle/ 3beams Corner/ 2beams Middle/ 3beams .5m 7.5 m 7.STANDARD CLASSIFICATION OF TOWERS Wind Zone : 47m/Sec Height 400kV Height Tower First Second Type Level Level TA TB TC TD TE TF 15 m 15 m 15 m 15 m 15 m 15 m NIL NIL NIL NIL NIL NIL Peak 7.5 m 7.5 m 7.5 m 7.5 m 7.5m 7.5 m 7.5 m 7.5m Angle of End /Middle Deviation ±30 deg ±30 deg 0 deg 0 deg 0 deg 0 deg End Middle End Middle End Middle TG TH TI TJ TK TL TM TN 22 m 22 m 22 m 22 m 15 m 15 m 15 m 15 m NIL NIL NIL NIL 7m 7m 7m 7m 7. NON-STANDARD TOWERS (MOGA) Tower Type Description 400kV TG TSP G5 GSP Beam at 15 m with peak 23m Beam at 23m with peak 30 m Beam at 15m (Twin Moose) Beam at 23m Beam at 11m Beam at 11m & 17.5m Beam at 11m & 17.5m (Single Moose) 220kV TA TB TC G1 G2 G3 .5m with peak 22m Beam at 11m (Single Moose) Beam at 11m (Twin Moose) Beam at 17. 5 m - 3m 2m 2m 1.5 m 4m 3m+road+5 m 3.5 m - 3.8 m 2m - .8 m 2.5 m 1.75m 2.5 m 3.5 m 2.5 m 7m 7m 6m 6m 7m 15 m 6.Typical dimensions between equipments… 400 kV 220 kV 132 kV 66 kV CB&ISO ISO&CT CB&CT Gantry Tower &ISO SA &PI& CVT LA & SR Road & SR 10. 48V) Battery Chargers Lighting Transformers Lighting Distribution Boards Rooms of Station-in Charge & staff Miscellaneous .Control Room Building Placement of Control. Relay & Protection Panels PLCC Panels AC Distribution Board DC Distribution Board Batteries (220V. Fire Fighting Pump House Placement of AC driven main pump DG driven stand-by pump Jockey Pump Air Vessels AC Distribution Board cum pump control panels Fire Water Tank . Miscellaneous Placement of LT Station (ACDB. Battery Bank & Battery Chargers) Diesel Generator Set with AMF Panel Security hut Office Buildings Other residential buildings . DCDB. Gas Insulated Substation (GIS) GIS in POWERGRID POWERGRID is constructing 132kV. 220 kV & 400 kV GIS substation Construction of 800 kV GIS is under consideration Technical Advantage of GIS All equipments are compact in size and enclosed in SF6 gas with metallic enclosure Area requirement of GIS is approx. Hence less execution time Costlier than AIS . 20% of conventional AIS Lesser structures & foundation works. Bus Bar Switching Schemes… Factors dictating choice of bus switching scheme 1) Reliability No Power interruption during Bus fault CB Maintenance No Power interruption during CB maintenance. Taking out CB for maintenance shall be easy 2) 3) Bus Bar Maintenance No Power interruption during Bus bar maintenance . Power interruption during such extension works.Bus Bar Switching Schemes… 4) Simplicity of protection arrangements Protection arrangements shall be simple for easy commissioning and regular checking Ease of Extension Extension of Bus bar necessary to take care of future expansion. 5) 6) Cost Optimal techno-economic solution . Bus Switching Schemes… Single Main Bus Scheme – with sectionaliser & without sectionaliser Single Main & Transfer Bus Scheme Double Main Bus Scheme Double Main with by-pass isolator Bus scheme Double Main & Transfer Bus Scheme One & Half Breaker Bus Scheme Double bus two breaker Scheme Ring Bus Scheme . .SINGLE BUS SCHEME Simplest and cheapest bus bar scheme Maintenance and extensions of bus bars are not possible without shutdown of the substation. Operation & maintenance of bus bar is easy. . SINGLE BUS WITH SECTIONALISER Similar to the single bus scheme except the sectionalising breaker or isolator. If a bus section breaker is provided busbar protection can detect fault on any section and trip the breakers connected to that section and isolate it. By keeping the sectionaliser open one section can be in service and the other can be taken for maintenance or extension. . The transfer bus coupler acts as the breaker for the circuit under by pass. Individual circuits have a bypass isolator to connect to the transfer bus and this isolator will be closed during bypass operation of that particular circuit. .SINGLE MAIN AND TRANSFER SCHEME Individual CB can be taken out for maintenance on-load at a time. For maintenance & extension of any one of the buses the entire load will be transferred to the other bus. On load bypassing of any circuit for breaker maintenance is not possible.DOUBLE BUS SCHEME Load will be distributed on both the buses and the bus coupler shall be normally closed. On load transfer of a circuit from one bus to the other bus is possible through bus isolators provided the bus coupler is closed and thereby two buses are at the same potential. . DOUBLE BUS WITH BY-PASS SCHEME . . The bus to which the transfer bus isolator is connected can be used as a transfer bus also. During the time a circuit is under bypass. the bus coupler will act as the breaker for the bypassed circuit.DOUBLE BUS WITH BY-PASS SCHEME This bus arrangement provides the facilities of a double bus arrangement & a main and transfer bus arrangement. . in addition to the two main buses there will be a separate transfer bus also. Since separate transfer bus is available there will be no need of transferring the load from one bus to the other bus unlike in a double main cum transfer bus arrangement. Other features are similar to the one described in double bus with by pass arrangement.DOUBLE MAIN AND TRANSFER SCHEME In this bus scheme. . power can be transferred from one feeder to another feeder through tie breaker . the middle breaker ties the two circuits and hence is called the tie breaker.BREAKER AND HALF SCHEME In this scheme. two circuit have three breakers. Breaker or bus maintenance is possible without any shut down of the feeder Even if both the buses are out of service. DOUBLE BUS TWO BREAKER SCHEME Each feeder is controlled by two breakers. In this arrangement breaker maintenance for any feeder circuit is easily possible without any shutdown. This arrangement is comparatively costlier than other scheme and hence followed in very important circuit only. . No bus bar protection required. Extension of ring scheme is difficult. .RING BUS SCHEME As long as the ring is closed load has two sources of supply and any circuit breaker can be taken out of service without affecting the supply. Bus Switching Selection considerations… Reliability Operation Flexibility Ease of Maintenance Short Circuit Level Limitation Simplicity of Protection Arrangement Ease of Future expansion Land availability Cost . A Case Study Of MOGA SUBSTATION . MOGA 400 KV D/C MOGA Bhiwadi 352 km (under const.) NRSSS-V .343 km (Loc 581-710) 800 KV KMTL-2 49.321) 220 KV D/C PSEB MOGA-I&II (400mtr) 800 KV KMTL-1 51.465 km (Loc 1. 63 MVAR Bhiwadi Line React(NRSSS-V) + Proposed : 765/400kV System and LILO of PSEB Nakodar Line 220 KV D/C PSEB MOGA-III &IV (400 mtr) 400 KV D/C JMTL 52.232 km (Loc 510-647) 220 KV D/C PSEB Jagraon-I&II (35km) 765 KV S/C Bhiwani .TRANSMISSION NETWORK OF MOGA SUBSTATION 400 KV D/C MHTL & MFTL 120.212 km (Loc 602-730) 800 / 400 / 220 KV MOGA SUBSTATION 1065 MVA (4 ICTs & 3 Reactors) + under const : 2 Nos. Layout of Moga Substation A Case Study D Type Layout (Residential area is more than switchyard area) DE Tower of 400kV D/C Hisar Line located in 220 kV Switchyard obstructing future expansion of 220 kV S/Y Location of Dead End Tower from Take off Gantry: Dead End Tower of 220kV Jagraon Line of PSEB was shifted from 30m to 100m outside boundary wall Gantry is designed for 200m span with angle deviation ±30 deg both in vertical & horizontal plane . LAYOUT OF COLONY & SUBSTATION COMPLEX . drawing but not existing . construction of approach roads for bays. incl old KMTL bays Re-orientation of rail track in reactor foundation LM marked in the engg.Layout of Moga Substation: A Case Study Bhiwadi Bays Extn works at Moga: Problems identified and changes proposed as per site conditions Take-off gantry of Bhiwadi Line shifted by 9m to reduce angle on gantry from 15 deg to 9 deg Matching of towers TG (Standard vs Non-standard) Dead End Tower of 400kV Moga-Bhiwadi Line was shifted as per site condition facilitating 765kV interconnection Foundation for CT in Tie Bay falling over already constructed cable trench No scope kept for Stone spreading. 25 MVAR Tertiary Reactors Shifting of Bus CVTs Conversion of 5 CT to 3 CT protection scheme Re-locating 245kV CT to enhance availability .Layout of Moga Substation A Case Study Re-locating 50 MVAR Bus Reactor Bay numbering in random order including Tie Bay T1 & T2 Isolators 400kV D/C Moga -Jalandhar Line in one Dia Provision of SVC 33kV. 2x240MVAR BUS REACTOR. 1X240 MVAR LINE REACTOR & TSS OF TALWANDI SABO OF PSEB) . 400 KV SWITCHYARD : 70. TOTAL AREA 1. ADDITIONAL LAND ACQUIRED : 33 Acers FOR 800 KV SWITCHYARD C. TOWNSHIP OPEN AREA B.A. TOWNSHIP BUILT-UP AREA 3.77 Acres : 24. 765/400KV ICT.88 Acres 2.60 Acres : 13. ADDITIONAL LAND BEING : 32.25 Acers : 31.3 Acres ACQUIRED FOR 765KV SUBSTATION (2X1500 MVA. Reactor-I I 400 KV 400 KV 220 KV BUS-I 220 KV BUS-I I 2189A 2189B 2189E1 2152 1000500/1A 2189E2 2189C 2289E1 2289A 2252 1000500/1A BUS COUPLER 2789E1 2752 2789E2 2789L 2789E3 2789C 2389E3 2289B 2789A 2789B 2389A 2389B 2389E1 2352 2889E2 2389T 1000500/1A 2389C 1000500/1A 2889E1 2852 2889A 2889B 2489E1 2452 2489A 2489B 2589E1 2552 2589A 2589B 2689A 2689B 2989E1 2652 2952 2989E2 2989T 2989E3 2989C 1000500/1A 2689E1 2989A 2989B FATEHABAD HISAR 2389E2 2589E2 2689E2 2489E2 2689T 2889L 2489L 2589L 2489E3 2489C 1000500/1A 2589E3 2589C 1000500/1A 2689E3 2689C 1000500/1A 2889E3 2889C 1000500/1A 21089A 21289A 21189A 21089E 21089B 21289B 21189B 21289E 1 21189E 1 1 21052 21152 21252 21089E 21189E 21289E 2 2 2 21289T 21089T 21189T 21089E 21189E 21289E 3 3 3 100021089C 21189C 21289C 500/1A 1000500/1A 1000500/1A 220 KV TRANSFER BUS 220 kV TBC BAY 220 kV PSEB-I I I ICT-I BAY 220 kV PSEB-IV 220 kV PSEB-I 220 kV PSEB-I I ICT-I I BAY ICT-I I I BAY Switchyard Fencing 220 kV 220 kV Jagraon-I Jagraon-II ICT-I V BAY . Reactor-I 25 MVAR Ter.433 kV 41052 1000500/1A 41089B E 41189T2E 1000500/1A 41089C E 41852 1000500/1A CONTROL ROOM 4989B 41089B 41889B 4689B 4989C 250 MVA ICT-I 250 MVA ICT-I I 250 MVA ICT-I I I 315 MVA ICT-IV 25 MVAR Ter.SINGLE LINE DIAGRAM OF 400 / 220 KV MOGA SUBSTATION (WITH FUTURE PLAN) 400 KV KISHENPUR-I 50 MVAR BUS REACTOR 41489R E 41489R 1000500/1A 41389T 2 41389T2 E 41352 63 MVAR LINE REACTOR 400 KV JALANDHAR-I 400 KV JALANDHAR-I I 400 KV KISHENPUR-I I 63 MVAR LINE 63 MVAR LINE REACTO R 41789R E 41789R 41652 Bhiwadi-I Bhiwadi-II 63 MVAR LINE 41789L E 41789L 41689T 2 1000500/1A 41789B 41689T2 E 41789B E 41752 41789A E 41789A 41989L E 41989L 42089T 1 41989B 41989B E 42052 42089T1E 42089T2E REACTO R 42089R E 42089R Spare 41289L E 41289L 41389T 1 41389T1E 41289B E 1000500/1A 41289A E 4189LE 4189L 1000500/1A 4389T1 4189BE E 4389T1 4352 1000500/1A 4289LE 4289L 4389T2 4389T2 E 4289BE 4289B 1000500/1A 4252 41289R E 41289R 41289B 4189B 1000500/1A 4152 41252 4189A 41289A REACTO R 41589R E 41589R 41589B 41589L E 41589L 41689T 1 41689T1 41589B E E 1000500/1A 41552 41589A E 42089T 2 41489B 41489B E 1000500/1A 41452 41489A E 41489A 4189AE 1 4189AE 2 4289AE 1 4289A 400 KV BUS-I 4289AE 2 41589A 41952 41989A E 41989A 42189A E 42189A 400 KV BUS-I I 4989A 4989AE 41089A E 41089A 41889A 41889A E 4589A 4589AE 4552 41889B E 4889T2 E 4889T2 41089C 41889C 1000500/1A 41889C E 4852 1000500/1A 1000500/1A 4589BE 4889T1 E 4589B 4889T1 4589L 4589LE 4452 1000500/1A 4489BE 4789T2 E 4489B 4789T2 4752 1000500/1A 4489A 4489AE 4689AE 4652 1000500/1A 4689BE 4789T1 E 4789T1 4689C 4689CE 4689A 4952 1000500/1A 4989BE 41189T1 E 100041189T 500/1A 1 41152 4989CE 1 MVA 33/0. . Small Scale industry House Small Scale industry TO BE DISMENTELED . Small Scale industry House Small Scale industry TO BE DISMENTELED . Small Scale industry House Small Scale industry TO BE DISMENTELED . MOGA SUBSTATION AUGMENTATION OF EXISTING TRANSFORMATION CAPACITY .IV 220 kV SHORT LINE A Approx.INSTALLATION OF ICT-IV AND ASSOCIATED BAYS SPARE 400 KV KISHENPUR-I 400 KV JALANDHAR-I 400 KV JALANDHAR-II 400 KV KISHENPUR-II 400 KV BHIWADI-I 400 KV BHIWADI-II 250 MVA ICT-IV 63 MVAR LINE REACTOR 63 MVAR LINE REACTOR LOCATION OF BHIWADI – I & II ( PROPOSED ) 400 KV BUS-I 400 KV BUS-II CONTROL ROOM 250 MVA ICT-I 250 MVA ICT-II 250 MVA ICT-III 400 KV HISAR-II 220 KV BUS-I 220 KV BUS-II 400 KV HISAR-I 50 MVAR BUS REACTOR 220 KV BUS-I 220 KV BUS-II IPS Al BUS on BPIs C Existing Conductor Bus D BUS COUPLER 220 KV TRANSFER BUS 220 kV TBC BAY 220 kV PSEB-III ICT-I BAY 220 kV PSEB-IV 220 kV PSEB-I 220 kV PSEB-II ICT-II BAY ICT-III BAY Switchyard Fencing 220 kV PSEB-V 220 kV PSEB-VI 220 KV ICT. length 50 m Conductor Bus B 220 kV SHORT LINE . ReactorII 250 MVA ICT-III 400 KV HISAR-II 250 MVA ICT-IV 25 MVAR Ter. 50m 400 KV HISAR-I A IPS Al pipe on BPIs C B Proposed 220 KV Conductor BUSI Proposed 220 KV Conductor BUS-II 2189A 2189E1 2152 2189B 2989A 2289A 2789A 2189B 2789E1 2 BUS COUPLER 1 2189E2 2189C 2752 2452 9 2952 2652 2852 2552 2389E2 235 2/889E2 2689E2 2 2489E2 2589E2 2789L 2989E2 2389T 2889L 2489L 2689T 2589L 2989T 2789E3 2889E3 2389E3 2689E3 2989E3 2489E3 2389C 2689C 2789C 2889C 2589C 2989C 2489C 220 KV TRANSFER BUS 2252 2789E2 ICT-I BAY ICT-II BAY ICT-III BAY 2189E1 7 2789B 2389B 2889B 2489A 2589A 2589B 2389A 2889A 2489B 2889E1 2389E1 2489E1 2589E1 2689E1 2689A 2689B 2989B 2989E1 21089A 21089E1 D 3 8 4 5 6 21189A 21289A 21289B 21089B 21189B 21289E1 21189E1 21052 21152 21189E2 21289E2 21189L 21289T 21189E3 21289E3 21189C 21289C 21252 21089E2 21089L 21089E3 21089C 220 kV TBC BAY 220 kV PSEB-III 220 kV PSEB-IV 220 kV PSEB-I 220 kV PSEB-II Switchyard Fencing 220 kV PSEB-V 220 kV PSEB-VI 220 KV ICTIV . Reactor-I CGL Existing 220 KV Conductor BUS-I Existing 220 KV Conductor BUS-II Approx. 400 KV BHIWADI-I&II LINES 50 MVAR BUS REACTORE 400 KV KISHENPUR-I 400 KV JALANDHAR-I 400 KV JALANDHAR-II 400 KV KISHENPUR-II 400 KV BHIWADI-I 400 KV BHIWADI-II SPARE 41452 41489B 41489R 41489RE 13 41389T1 41352 41389T1E 41489BE 41289LE 41289L 41389T2 41289R 4189LE1 4189L 4389T1 4389T1E 3 4352 41589RE 63 MVAR LINE REACTOR 63 MVAR LINE REACTOR 41689T1E 41389T2E 41289BE 41289B 4189B 4189BE1 41289RE 4289LE 4289L 4189T2 4389T2E 4289B 4289BE1 41589L 41589LE 41689T1 16 41652 41589R 41789LE 41789L 41689T2 41689T2E 41989LE 41989L 42089T1 20 42089T2 41589B 41589R 41589BE LOCATION 41789BE 41789B OF BHIWADI – I & 17 II ( PROPOSED ) 41752 41789AE 41789A 42089T1E 42052 41989B 41989BE 42089T2E 14 41489AE 41489A 15 4252 41589AE 41589A 19 41952 41989AE 41989A 42189AE 42189A 41289AE 41289A 12 41252 4152 1 4189AE1 4189A 4189AE2 400 KV BUS-I 400 KV BUS-II 2 4289AE2 4289A 4289AE2 41552 4989A 4989AE 4952 41089A 41089AE 41889A 41889AE 41852 4589A 4589AE 4552 4489A 4489AE 4689A 4689AE 9 41189T1E 4989BE 10 11 41152 1 MVA 33/0.MOGA SUBSTATION AUGMENTATION : ICT-IV & ASSOCIATED 220 KV BAYS.433 kV 41052 18 4889T2E 5 8 4589AE 4889T1E 4889T1 4589LE 4452 4589L 4589A 4489L 4489B 4 4789T2E 6 7 4652 CONTROL ROOM 4989B 41189T1 4989C 4989CE 250 MVA ICT-I 41089BE 41189T2E 41189BE 41089B 41889BE 41089C 41089CE 41889C 4489BE 4689BE 4789T1E 4789T1 4689B 4689C 4689CE 4852 4889T2 41889CE 4789T2 41189T2 4752 4489LE ISOL:KEP 250 MVA ICT-II 25 MVAR Ter. SINGLE LINE DIAGRAM OF 220kV DMT SCHEME 400 KV BUS-I 400 KV BUS-II 4989A 4989AE 41089AE 41089A 4952 1000-500/1A 4989BE 41189T1E 4989B 41189T1 4989C 4989CE 1000-500/1A 41152 41089CE 1000-500/1A 41089BE 41189T2E 41052 41089B 1000-500/1A 41089C 250 MVA ICT-I 250 MVA ICT-I I 220 KV BUS-I 220 KV BUS-I I 2189A 2189B 2189E1 2152 2289E1 1000-500/1A BUS COUPLER 1000-500/1A 2389E2 2389T 2489E2 2489L 2689E2 2689T 2289A 2252 2389E1 2352 2489E1 2452 2289B 2389A 2389B 2689A 2489B 2689E1 2652 2689B 2489A 2189E2 2389E3 2189C 2389C 1000-500/1A 2489E3 2489C 2689E3 2689C 1000-500/1A 220 KV TRANSFER BUS 1000-500/1A ICT-I BAY 220 kV PSEB-I ICT-I I BAY . SINGLE LINE DIAGRAM OF 220kV DMT SCHEME WITH 245kV CT RELOCATED 400 KV BUS-I 400 KV BUS-II 4989A 4989AE 41089AE 41089A 4952 1000-500/1A 4989BE 41189T1E 4989B 41189T1 4989C 4989CE 1000-500/1A 41152 41089CE 1000-500/1A 41089BE 41189T2E 41052 41089B 1000-500/1A 41089C 250 MVA ICT-I 250 MVA ICT-I I 220 KV BUS-I 220 KV BUS-I I 2189A 2189B 2189E1 2152 2289E1 1000-500/1A BUS COUPLER 1000-500/1A 2389E2 2289A 2252 2389E1 2352 1000-500/1A 2389T 2489E1 2452 1000-500/1A 2489E2 2489L 2689E2 2289B 2389A 2389B 2689A 2489B 2689E1 2652 1000-500/1A 2689B 2489A 2689T 2189E2 2389E3 2189C 2389C 2489E3 2489C 2689E3 2689C 1000-500/1A 220 KV TRANSFER BUS 1000-500/1A ICT-I BAY 220 kV PSEB-I ICT-I I BAY . . 1 Section 2 .75 m 0.95 m 1.2 Section 3 – 3 Section 4 – 4 1.40 m 5 both sides 3 one side 2 one side 1 one side .05 m 0.CABLE TRENCH Section Inner Dim Racks Section 1 . 2009 (11:30 TO 12:30) MANOJ KUMAR. MOGA . MANAGER (S/S).ERECTION.02. TESTING & COMMISSIONING OF CT & CVT (UP TO PRECOMMISSIONING CHECKS) 17. ERECTION OF CVT INTRODUCTION Devices used to get the replica of primary voltage which shall be suitable for measuring instruments and protective relays. of cores as per requirement CVTs used generally above 220kV for economic reasons also obviates need for separate coupling capacitor for PLCC . No. Pre Commissioning Tests of CT Polarity Test Magnetization Curve Test Ratio Test Primary Current Injection Test Secondary Current Injection Test .