The document discusses various types of auxiliary power supply systems used at a power plant. It describes the different voltage levels used - 11kV, 6.6kV, 415V, 240V - and lists examples of equipment operated at each level. It also provides information on the switchgears, transformers, and circuit breakers that form part of the supply system and help distribute power at different voltages. Diagrams are included to illustrate the configuration and components of the 33kV, 6.6kV, and 415V switchgear systems.

4. AUX. SUPPLY
The service voltage which we are adopted in RSTPS are 11KV,
6.6KV , 415V 3PH AC supply and 240V 1PH AC supply.
11KV for Stage 2/3 MDBFPs.
6.6KV for station/unit HT auxiliaries like BFP s (stage-I), Mills,
ID/FD/ PA fans, CEPS, CW, RW Pumps & IAC/PAC etc.
415V for station aux like BAHP/FALP, Service water pumps,
unit aux like Seal Air fan, Lube oil pumps, AC seal oil pumps
and Centrifuge etc.
240V supply for lighting and welding.
These supplies are fed through the different switchgears

5. What are switchgears?
The equipment which normally fall in this category are:
Circuit Breakers
Isolators
Load break switches
Earth switches
Switch fuse units etc.
The switchgears are fed through different transformers

6. Transformer
Generator Transformer
Tie Transformer
The generator is connected to this transformer by means of bus ducts. This
transformer is used to step up the generating voltage of 18 / 21 KV to 400 KV .
This transformer is provided OFAF cooling and Off load tap changer.
There are total 4 No. of Tie Transformers are provided for feeding supply for
internal requirements. It steps down 400 KV to 33KV This transformer is
provided OFAF cooling and Off load tap changer.

7. Station Transformer
The station transformer is required to feed power to the auxiliaries
during start-ups, and C- auxiliaries when unit is in service.,
This transformer is normally rated for initial auxiliary load
requirements of unit.
It is provided with On load tap changer to cater to the fluctuating
voltage of the grid.
Unit Auxiliary Transformer
The UAT draws its power from the main bus duct-connecting
Generator to the GT. The total KVA capacity of unit Auxiliary
transformer require can be determined by assuming 0.85 power factor
and 0,9 efficiency for total load with a safe margin of 20%. It is
provided with On load tap changer to cater to the fluctuating voltage
of the grid.
Transformers

8. BREAKER
TRANSFORMER
ISOLATOR
SWITCH CUM
FUSE UNIT
FUSE
CONTACT
400 KV LINE
33 KV LINE
11 KV LINE
6.6 KV LINE
415 V LINE
220 DC LINE
5
SYMBOLS

9. 33KV SWITCHGEAR
UNIT # 1
GEN
400 KV BUS # 2
400 KV BUS # 1
ST # 6
ST # 3 ST #
4
ST #
5
TIE # 1
75 MVA
400/33 KV
SEC # A SEC # B
SEC # C SEC # D SEC # E ~
~
GT # 5
21/400 KVTIE # 2
75 MVA
400/ 33 KV
TIE # 3
100MVA
400/ 33
KV
6
TIE # 4
100 MVA
400/ 33 KV
~
~
GT # 1
240 MVA
18/400 KV
UNIT # 5
GEN
ST # 1 ST # 2 ST #7
SEC #F

11. TIE # 2
400/33 Kv
75 MVA
TIE # 1
400/33 Kv
75 MVA
spare
WTP-2
CW-1
ST-1
CHPAUG-1
ST-6
COL-3
SWYD-1
TIETOSEC-F
COL-2
WTP-1
CW-2
ST-2
CHPAUG-2
CONST-2
TIETOSEC–E
SWYD-2
SEC-A SEC-BB/C
33 KV STAGE-I SWITCHGEAR
7

12. 33 KV
MERRYLIN-
GERRIN
MAKE SF6

13. SHSLURRYLTG
TIETO1CW1
UNITSWGR-1B
UNITSWGR-2B
AIRCOMP-A
FOLTG
CHP-B
ASS-1
DAETP-1
UNITSWGR–3A
SPARE
UNITSWGR–1A
DAETP-2
UNITSWGR–2A
ST –1
33 / 6.6 KV
19 / 25 / 31.5 MVA
ST –2
33 / 6.6 KV
19 / 25 / 31.5 MVA
STLT-4
6.6 / 0.433
1.65 MVA
STLT-3
6.6 / 0.433
1.65 MVA
STLT-1
6.6 / 0.433
1.65 MVA
STLT-2
6.6 / 0.433
1.65 MVA
AIRCOMP
SWGR-B
CHP-A
ASXMER-2
UNITSWGR-3B
6.6 KV STATION SWITCHGEAR
B/C
1S1/2S1
B/C
1S2 / 2S2
1S1
1S2
2S1 2S2
ASHXMER-3
STN LT SWGR - 1 STN LT SWGR - 2
SEC-A SEC-B SEC-A SEC-B
8
NOTE: ALL SECTIONS HAVE BUS
VTS
LINE PT PANELS ARE
AVAILABLE IN 1S1 & 2S2

14. 6.6 KV STATION SWITCHGEAR
INCOMER FROM STATION TRANSFORMER
PROTECTIONS
 Remote trip
 Local trip
 Mech.trip
 Elect.trips from
• E/F Relay
• IDMT O/C: R,Y,B phases.
INTERLOCKS
 Station transformer HT breaker
trip.
 Trips when Incomer from station
transformer and buscoupler is
ON in service position with trip
selection in this incomer.
PERMISSIVES
• 33 KV side charged.
• No elect trip from
• E/F Relay
• IDMT O/C: R,Y,B phases.
•No elect trip from Buscoupler.
• No Continuous close command
64

15. 6.6 KV STATION SWITCHGEAR
BUSCOUPLER
PROTECTIONS
 Remote trip
 Local trip
 Mech.trip
 Elect.trips from
• E/F Relay
• IDMT O/C: R,Y,B
phases.
INTERLOCKS
• Trips when both
Incomers from station
transformer are ON in
service position with trip
selection in buscoupler..
PERMISSIVES
• No elect trip from
• E/F Relay
• IDMT O/C: R,Y,B phases.
•No elect trip from Incomer from station
transformer
• No Continuous close command
65

17. 6.6 KV UNIT SWGR # A
6.6 KV UNIT SWGR # B
UT # A
25 MVA
18/6.6KV
6.6KV UNIT SWITCHGEAR
∼
200MW GEN
400KV BUS # 1
400KV BUS # 2
UT # B
25 MVA
18/6.6KV
FROM 1S2 / 1S2 / 1S1
(UNITS 1 / 2 / 3 )
FROM 2S1 / 2S1 / 2S2
(UNITS 1 / 2 / 3 )
GT
18 / 400 KV
240 MVA
14

18. 6.6 KV UNIT SWITCHGEAR.
TIE INCOMER FROM STATION SWGR.
PROTECTIONS
 Remote trip
 Local trip
 Mech.trip
 Elect.trips from
• E/F Relay CTU 12(64)
• IDMT O/C Relay – R,Y,B phases
INTERLOCKS
 Breaker trips when UAT incomer is ON
in service position.
 Breaker closes on auto from command.
from GRP.
PERMISSIVES
• No elect trip from
• E/F Relay CTU 12(64)
•IDMT O/C Relay – R,Y,B
phases
• No elect trip from UAT incomer.
• upstream Isolator / breaker in service
/ closed
• No Continuous close command
57

19. 6.6 KV UNIT SWITCHGEAR.
INCOMER FROM UNIT TRANSFORMER
PROTECTIONS
 Local trip
 Mech.trip
 Remote trip
 Elect.trips from
 E/F Relay (51) -CDG
• IDMT O/C: R,Y,B, phases.
 Trip from GRP
INTERLOCKS
 Breaker trips when TIE incomer is
ON in service position
PERMISSIVES
• No elect trip from
• E/F Relay (51) -CDG
• IDMT O/C: R,Y,B, phases.
•Unit synchronised.
•No elect trip from TIE incomer.
• No Continuous close command
58

20. 6.6 KV,
ASEA MAKE
MOCB,
CW-I,
COMP-1,
RAW WATER
P/H

21. 6.6 KV STAGE-2,
SIEMENS MAKE,
VACUUM CB

22. 6.6 KV ABB,SF6,LWTP TRFR 1&2

23. SEC-A
IAC-1
UNIT LIGHTING XFMR
BFP-C
BFP-A
PA FANS A,C AND E
MILLS A,C AND E
CEP-A
FD-B
ID-B
UAT-A
ESP-A
SEC-B
BFP-C
BFP-B
PA FANS B,D AND F
MILLS B,D AND F
CEP-B
FD-A
ID-A
UAT-B
ESP-B
UNIT-1
SEC-A
IAC-3
UNIT LIGHTING
XFMR
BFP-C
BFP-A
PA FANS A,C AND E
MILLS A,C AND E
CEP-A
FD-A
ID-A
UAT-A
ESP-A
SEC-B
BFP-C
BFP-B
PA FANS B,D AND F
MILLS B,D AND F
CEP-B
FD-B
ID-B
UAT-B
ESP-B
UNIT-2
SEC-A
UNIT LIGHTING
XFMR
BFP-C
BFP-A
PA FANS A,C AND E
MILLS A,C AND E
CEP-A
FD-A
ID-A
UAT-A
ESP-A
SEC-B
BFP-C
BFP-B
PA FANS B,D AND F
MILLS B,D AND F
CEP-B
FD-B
ID-B
UAT-B
ESP-B
UNIT-3
6.6 KV UNIT SWITCHGEAR
15

24. HT MOTOR FEEDER
PERMISSIVES
 No elect trip from
 (i) E/F Relay
 (ii) Inst O/C Relay: R, Y,B Phases
 (iii) Lockout rotor
 (iv) Differential protection
 IDMT O/C: R, B phases.
 Overload
 EPB released
 Process permissive
 No Continuous close command
PROTECTIONS
 Local trip
 Remote trip
 Mech.trip
 EPB Pressed.
 Elect.trips from
• E/F Relay
• Inst O/C Relay R, Y,B Phases
 Lockout rotor
 Differential protection
 Overload.
 Process trips.
INTERLOCKS:
 Bus under voltage trip
63

25. TRANSFORMER HT SIDE FEEDER
PERMISSIVES
 No Elect trip from
 E/F Relay
 IDMT O/C Relay (51) R, Y, B Phases (or)
differential protection..
 Inst O/C Relay (50)
 R-Phase
 Y-Phase
 B-Phase
 Wdg.temp high
 Transformer oil temp. high
 Bucholtz trip
 No Continuous close command
PROTECTIONS
 Local trip
 Mech.trip
 Remote trip
 Elect.trips from
 E/F Relay
 IDMT O/C Relay (51) R, Y, B Phases
(or) differential protection..
 Inst O/C Relay (50)
 R-Phase
 Y-Phase
 B-Phase
 Transformer oil temp. high
 Wdg. temp. high
 Buchholtz trip
THIS IS APPLICABLE TO ESP, UAT , unit ltg, FO ltg, Ash slurry ltg, StationLT , CT LT, WTP LT, switchyard LT, ASH
SLURRY TRANSFORMERS HT SIDE BREAKER
62

26. UAT - A
6.6 / .433 KV
1.6 MVA
TGMCC–A
TGMCC–C
BMCC–A
BVDDC–A
TGMCC–B
TGMCC–D
BMCC–B
BVDDC–B
SEC-A SEC-BB/C
415V UNIT LT SWITCHGEAR
UAT - B
6.6 / .433 KV
1.6 MVA
SPARE
SPARE
EMCC
From DG Set
EQUIPMENTS
CHARGERS
EMERGENCY
LTG
UPSALT
SOURCE
PAFANFLOP
MCC
EQUIPMENTS:
TGOP
TURNING GEAR MOTOR
VEF-B
SCANNER AIR FAN-A
APH-A AUX DRIVE
APH-B AUX DRIVE
CHARGERS:
FLOAT MAIN
BOOST CHARGER
UPS CHARGER-A
FROM
UNIT SWGR - A
FROM
UNIT SWGR - B
16

28. DG SWITCHGEAR
DG SET – 2
625 KVA
DG SET – 1
625 KVA
415 V LT BUS
TOUNIT–1EMCC
TOUNIT–2EMCC
TOUNIT–3EMCC
TOSWYD
25

29. PERMISSIVES
1 No Elect. trips from
Inst.O/C relay R,Y,B-phases
E/F relay
1 Upstream breaker closed in
service position.
3 No Continuous close command.
4 No Elect. trip from BUS COUPLER
5 Breaker panel door closed
UNIT LT SWITCHGEAR
INCOMER A &B
PROTECTIONS
01 Local trip
02 Remote trip
03 Mech trip
04 Inst O/C trip R,Y,B-phase
E/F relay
INTERLOCKS
01 Trips on Upstream breaker off.
02 Trips on breaker panel door open.
59

30. PERMISSIVES
1 No Elect. trips from
Inst.O/C. R, Y, B -phases
Earth Fault
2 No Elect. trips from
INCOMER - A
INCOMER - B
3 No Continuous close command.
4 Breaker panel door closed
UNIT LT SWITCHGEAR
BUS COUPLER
PROTECTIONS
1 Local trip
2 Remote trip
3 Mech trip
4 Electrical trips
Inst.O/C. R, Y, B -phases
Earth Fault
INTERLOCKS
01 Trips when Both incomers are ON and
in service position
02 Trips on breaker panel door open.
61

31. UNIT LT SWITCHGEAR
FEEDER (BMCC, BVDDC, TG MCC)
PROTECTIONS
1 Mech trip
2 Local trip
2 Overload trip
3 Short circuit trip.
INTERLOCKS
1 Upstream breaker OFF.
2 Trips on breaker panel door
open.
PERMISSIVES
1 No Elect. trips from Inst.O/C
relay R,Y,B-phases
2 No Continuous close command.
3 Breaker panel door closed
60

32. 415V BOILER MCC
SEC - A SEC - B
SEC-A
MILLS A,C,E LUB OIL PUMPS
-GRAVIMETRIC FEEDERS A,C,E
-PA FANS A,C,E ISOLATING DAMPERS
-ROTARY FEEDERS C,D,E,F,G,H
-LP DOSING-A
-HP DOSING-A
-SEAL AIR FAN-B
-SH STAGE-I LHS AND RHS SPRAY BLOCK V/VS
-AUX PRDS V/V F036
-HPBYPASS OSU-1
-SOOT BLOWER CABINET SUPPLY
-D/A HIGH LEVEL CONTROL BYPASS V/V F046
-CG-A,C
APH-A MAIN MOTOR
SEC-B
MILLS B,D,F LUB OIL PUMPS
-GRAVIMETRIC FEEDERS B,D,F
-PA FANS B,D,F ISOLATING DAMPERS
-ROTARY FEEDERS A,B, I,J,K,L,M,N,O,P
-LP DOSING-B
-HP DOSING-B
-SEAL AIR FAN-A
-SH STAGE-II LHS AND RHS SPRAY BLOCK V/VS
-AUX PRDS INLET V/V F002 AND TIE V/V F010
-HPBYPASS OSU-2
-BOILER DEWATERING CABINET SUPPLY
-CRT MAKE UP CONTROL BYPASS V/V F047
-CG-B,D
-APH-B MAIN MOTOR
-SCANNER AIR FAN-B
-ECO INLET V/V F002
-UPS CHARGER -B
FROM UNIT LT
SWGR-A
FROM UNIT LT
SWGR-B
400 A
400 A
400 A
17

33. 415V BOILER VDDC
SEC - A SEC - B
SEC-A
-START UP VENT F027
-AUX STEAM TO SCAPH-B INLET,OUTLET AND
REGULATING /VS F020, F022, F023
-ECO RECIR V/V F005
-FRS 30% INLET AND OUTLET V/VS
-BUNKER GATES A,C,E
-ESP PASS I AND II INLET AND OUTLET DAMPERS
ID-B INLET AND OUTLET DAMPERS
-AUX STEAM TO D/A PREHEATING V/V F046
-SH HEADER VENTS F690,F680 AND F682
-RHS MAIN STEAM STOP V/V F030
CBD ISO V/V F012
-AUX STEAM TO SCAPH-A INLET,OUTLET AND
REGULATING /VS F024, F026, F027
-EBD V/VS F017 AND F018
SEC-B
-RH VENT F710
-SH HEADER VENTS F700,F698,F692
-FRS 100% RHS AND MIDDLE INLET AND
OUTLET V/VS
-BUNKER GATES B,D,F
-ESP PASS III AND IV INLET AND OUTLET
DAMPERS
-ID-A INLET AND OUTLET DAMPERS
-LHS MAIN STEAM STOP V/V F040
-RH ATTEMPERATION BLOCK V/V F095
FROM UNIT LT
SWGR-A
FROM UNIT LT
SWGR-B
400 A
250 A
250 A
18

34. 415V TGMCC - A
FROM UNIT LT
SWGR-A
TIE FROM / TO
TGMCC-D
BFP-A,B,C DISCHARGE V/VS AND INTEGRAL BYPASS V/VS
BFP-A,B,C LUB OIL PUMPS
TURBINE SIDE MS STOP V/VS F007 AND F008
MOT CLEAN OIL PUMP AND DIRTY OIL PUMP
CRH DRAIN V/VS F764,F766,F767,F765
LPH-1 INLET,OUTLET AND BYPASS V/VS F020,F021 AND F022
TURBINE AOP
CEP A AND B DISCHARGE V/VS
LP BYPASS DRAIN V/VS F762 AND F763
LP BYPASS OSU 1 AND 2
GSEB A AND B
AUX PRDS OSU
200 A250 A
19

35. 415V TGMCC - B
FROM UNIT LT
SWGR-B
TIE FROM / TO
TGMCC-C
VEF-A
ESVS AND IVS SEAT DRAINS
HP TURBINE DRAIN V/VS
SEAL STEAM FEED V/V(F001),SHUT OFF V/V(F003) AND
UNLOADING V/V(F004) AND BYPASS V/V(F002)
TURBINE PREWARMING V/V F005
CPU INLET AND OUTLET V/V
ARP RELAY CABINET
MOT CENTRIFUGE SUPPLY
UNIT BATTERY CHARGER FLOAT(SB)
800 A 400 A
20

36. 415V TGMCC - C
TIE FROM/TO
TGMCC-B
FROM UNIT LT
SWGR-A
-SEAL OIL PANEL SUPPLY
-BUS DUCT PRESSURISATION AND HOT AIR BLOWING
SUPPLY
-EXCITATION PANLEL SUPPLY
-GT COOLER S/B SUPPLY
-UT-B COOLER MAIN SUPPLY
-UT-A COOLER S/B SUPPLY
-TURBINE SIDE DEWATERING PUMPS PANEL
-EXCITATION THYRISTOR FANS AUX SUPPLY
-EXCITATION FIELD FLASHING SUPPLY
MULSIFIER SYSTEM(MOT AND ROT)
400 A800 A
21

37. 415V TGMCC - D
TIE FROM / TO
TGMCC-A
FROM UNIT LT
SWGR-B
•AUX STEAM TO SEAL STEAM CONTROL BYPASS V/V
•UT-A COOLER MAIN SUPPLY
•UT-B COOLER S/B SUPPLY
•ALL EJECTORS AIR AND STEAM SIDE V/VS
•ALL HEATERS EXTRACTION STEAM BLOCK V/VS
•HRH LINE DRAINS,MS LINE DRAINS,CRH LINE DRAINS
•GT COOLER MAIN SUPPLY
•HPH 5 AND 6 INLET,OUTLET AND BYPASS V/VS
•TURBINE LUB OIL TEMP CONTROL V/V F023
•HP FLASH TANK ATTEMPERATION V/V F033
•LP BYPASS LINE DRAIN V/V F726,F727
•CPU FLOW CONTROL BYPASS V/V
•EXHAUST HOOD SPRAY BYPASS V/V F020
•CW PASS A AND B INLET AND OUTLET V/VS
•VACUUM BREAKER V/V
•D/A VENT V/V
•ALL HEATERS NORMAL AND ALTERNATE DRIP
CONTROL BYPASS V/VS
•CONDENSER MIN RECIRCULATION V/V BYPASS V/V
•HOTWELL LEVEL CONTROL V/V BYPASS V/V
•HOTWELL MAKE UP BYPASS V/V F043
200 A
250 A
22

38. VENTILLATION MCC
AWU C&D BLOWERS AND PUMPS SUPPLY
TG ROOF EXTRACTORS(5 NOS)
C&I DOCK HOUSE
DAS ROOM A/C PACKAGE UNIT
EXHAUST AIR FANS
-VENTILLATION MCC ROOM(2 NOS)
-D/A ROOF EXTRACTORS(2 NOS)
-UNIT BATTERY ROOM(2 NOS)
-BUNKER LEVEL DUST EXTACTION FANS(5 NOS)
AIR WASHER MCC
AWU A AND B BLOWERS AND PUMPS
ARCW PUMPS A AND B
FROM STN
LT SWGR
FROM STN
LT SWGR
630 A
400 A
23

39. 415V ESP SWITCHGEAR
BOARD-A
BOARD-B
ESP PASS I AND II FIELDS
ESP PASS I AND II AUX SUPPLY
ESP ZERO FIELD AND AUX PANEL
ESP A/C
ESP A/C PACKAGE UNIT
ESP PASS III AND IV FIELDS
ESP PASS III AND IV AUX SUPPLY
APH FIRE DETECTOR
WELDING SUPPLY(SPARE)
ESP TRF-A
6.6/.433 KV
1.25 MVA
ESP TRF-B
6.6/.433 KV
1.25 MVA
FROM UNIT
SWGR-A
FROM UNIT
SWGR-B
BC
24

42. DC SYSTEM OF RAMAGUNDAM
 TO OPERATE FROM BATTERIES
FOR ATLEAST 60 MINUTES
FOLLOWING COMPLETE FAILURE
OF ALL AC SUPPLIES
 TO OPERATE FROM BATTERIES
FOR ATLEAST 10 HRS FOLLOWING
FAILURE OF ALL BATTERY
CHARGERS

43. DC LOADS
 INSTRUMENTS
 INDICATIONS, ANNUNCIATIONS &
ALARMS
 SWITCHGEAR CLOSING & TRIPPING
 CONTROLS,PROCTECTION &
INTERLOCKS
 TELECOMMUNICATIONS
 PLCC & PA SYSTEM
 DC LIGHTING
 DC DRIVES

44. DC SYSTEM
 BATTERY CHARGERS [TWO/THREE]
 BATTERY BANKS [ONE/TWO]
 DC DISTRIBUTION BOARDS [ONE/TWO]
 DC FUSE BOARDS
 UN EARTHED SYSTEM
 CHARGER TROUBLE, DC EARTH FAULT
AND DC VOLTAGE ABNORMAL ALARMS
IN UCB

45. 220 V UNIT DCDB
BOOST CHARGER BATTERY BANK FLOAT MAIN FLOAT S/B
ELECTROMAGNETIC
BOARD-1
TIEFEEDER
LOGICDB
DCLTG
A ELECTROMAGNETIC
BOARD-2
220 V DCDB
500 A
X
SW4 SW3
SW4 SW4
•CONTACTOR X OPENS ON
BOOST CHARGER ON
TIE FEEDERS TO UNITS:
UNIT- 1: FROM UNIT –2 DCDB
FROM SWYD DCDB SEC-1
UNIT-2 : FROM UNIT – 1 DCDB
FROM UNIT- 3 DCDB
UNIT- 3 : FROM UNIT- 2 DCDB
DCEOPSTARTER
PANLE
DCSEALOILPANEL
26

46. UNIT-1
A: DC SOURCES FOR
6.6 KV UNIT SWGR A AND B MAIN
415 UNIT SWGR - A AND B
EMCC I/C-1 & EMCC I/C –2
6.6 KV STN SWGR 1S1 AND 1S2 MAIN
6.6 KV STN SWGR 2S1 AND 2S2 MAIN
415 STN SWGR - 1A AND 1B MAIN
415 STN SWGR - 2A AND 2B MAIN
UNIT-1 MLDB
AIR COMPRESSOR ANNUNCIATION PANEL
6.6 KV COMRESSOR SWGR 1
DG SWGR PANEL-2
ESP SWGR
INTERCOM EMERGENCY SUPPLY
UNIT-2
A: DC SOURCES FOR
6.6 KV UNIT SWGR A AND B MAIN
415 UNIT SWGR - A AND B
6.6 KV UNIT SWGR – 3A & 3B STANDBY
6.6 KV UNIT SWGR – 1A & 1B STANDBY
415 UNIT SWGR - 3A AND 3 B STANDBY
EMCC I/C-1
EMCC I/C –2
ESP SWGR
DC FUSE BOARD – 1
-UCR AC
-STN LT 1 & 2
-STN SWGR IS1 & 2S1
-CSSAEP
DC FUSE BOARD – 2
-STN LT 3 & 4
-STN SWGR IS2 & 2S2
-UNIT – 1 LT SWGR
- DG SWGR
INTERCOM EMERGENCY SUPPLY
UNIT-3
A: DC SOURCES FOR
6.6 KV UNIT SWGR A AND B MAIN
415 UNIT SWGR - A AND B
6.6 KV UNIT SWGR – 2A & 2B STANDBY
415 V UNIT SWGR – 2A & 2B STANDBY
EMCC I/C-1
EMCC I/C –2
ESP SWGR
INTERCOM EMERGENCY SUPPLY
220 V UNIT DCDB SUPPLY DISTRIBUTION
27

48. ASH SLURRY LT SWITCHGEAR
AS TRF-1
6.6 / .433 KV
1.6 / 2 MVA
SPARE-3NOS
H2PLANTMCC
ASSERIES-1
ASSERIES-2
FOUNLOADING
MCC
ASSERIES-3
CANTEEN
SUPPLY
ASMCC
SERVIVE
WATERMCC
SEC-A B/C--2B/C-1
AS TRF-3
6.6 / .433 KV
1.6 / 2 MVA
SPARE
CHIMNEYMCC-1
PRESSUREPARTS
MAINTWORKSHOP
CHIMNEYMCC-2
SEALWATER
PUMP-3
FOPRESSURISING
MCC
SPARE
ASSERIES4
ASSEIRS-5
H2PLANTMCC
AS TRF-2
6.6 / .433 KV
1.6 / 2 MVA
SEC-C
SEC-B
FROM 1S1 FROM 2S1
FROM 2S2
CANTEENSUPPLY
30

49. 6.6 KV CW SWITCHGEAR
1CW2
2CW2
2CW11CW1
B/C
B/C
CTLTXFMER-1
AW&FFXFMER-1
CWP/P-1
CWP/P-2
SPARE
RAWWATER
SWGRSEC-A
CWP/P-5
CWP/P-6
LWTPXFMR-1
DMERVICE
XFMER-1(STAGE-II)
CTLTXFMER-3
WAGONTIPPLER
XFMER-1
WAGONTIPPLER
XFMER-2
CWP/P-3
CWP/P-4
DMERVICEXFMER-2
STAGE-II
CTLTXFMER-4
CTLTXFMER-2
CWP/P-7
AW&FFXFMER-2
TIETORAWWATER
SWGRSEC-B
CTLTGXFMER
RAWWATER
P/P-6
RAWWATER
P/P-3
CW XFMER-1
33 /6.6/6.6 KV
20/25 MVA
CW XFMER-2
33 /6.6/6.6 KV
20/25 MVA
FROM 33 KV SWGR
SEC-A
FROM 33 KV SWGR
SEC-B
TIEFROM
2S1SWGR
BUSVT
BUSVT
BUSVT
BUSVT
LWTPXFMR-2
37
NOTE: ALL SECTIONS HAVE LINE PT CUBICLES

50. 6.6 KV CW1 / CW2 / WTP SWITCHGEAR
BUSCOUPLER
PROTECTIONS
 Remote trip
 Local trip
 Mech.trip
 Elect.trips from
• E/F Relay
• IDMT O/C: R,Y,B phases.
INTERLOCKS
• Trips when both Incomers are ON
in service position with trip
selection in buscoupler.
• Closes on auto if the following
conditions are satisfied.
 Any incomer trip and No
fault on this section
 Bus under voltage operated
 Buscoupler selection in
auto
PERMISSIVES
• No elect trip from
• E/F Relay
• IDMT O/C: R,Y,B phases.
•No elect trip from any of the Incomers.
• No Continuous close command
67

51. CLARIFIEDWATERPUMP-7 FROM 33 KV SWGR SEC-A
6.6 KV WTP SWITCHGEAR
SEC-A SEC-B
FROM 33 KV SWGR SEC-B
CLARIFIEDWATERPUMP-1
CLARIFIEDWATERPUMP-3
CLARIFIEDWATERPUMP-5
WTPLTXFMR-1
SATCOMXFMR-1
CLARIFIEDWATERPUMP-6
CLARIFIEDWATERPUMP-4
CLARIFIEDWATERPUMP-2
WTPLTXFMR-2
SATCOMXFMR-2
B/C
WTP XFMR-1
33 / 6.9 KV
5 MVA
WTP XFMR-2
33 / 6.9 KV
5 MVA
BUSVT
BUSVT
SPARE
44
NOTE: BOTH SECTIONS HAVE LINE PT CUBICLES

53. Indicates breaker in open condition
Indicates breaker in close condition
closed
B/C 2
open
Col I Col II Col IIIRDM I RDM II
From SEC F Sec B Sec A
#1 #2 #3
NEW COLONY SWITCHGEAR AS ON 25/05/05
B/C 1
All
Transformers
are 4MVA

54. THANK
YOU