The document provides information about various components and circuits in a substation including: - Circuit breaker auxiliary switches, pressure switches, annunciation, and indication circuits. - Circuit breaker operating mechanisms, arc quenching methods, and interlocks. - Closing and tripping circuits for circuit breakers. - Types of relays including bistable, monostable, anti-pumping contactor, and pole discrepancy relays. - Inputs and outputs of relays, local/remote switches, and wiring types. - Potential transformers, current transformers, and their distribution including nameplate details. - AC and DC circuits and their purposes including protection, control

1. GOPALA KRISHNA

2. BASICS
1. NO & NC CONTACTS
2. CIRCUIT BREAKER AUX SWITCH
3. ISOLATOR AUX SWITCH
4. PRESSURE SWITCH & DENSITY MONITOR
5. ANNUNCIATION
6. INDICATION
7. SEMOPHORE
8. CB OPERATING MECHANISAMS
9. CB ARC QUENCHING METHODS
10. INTERLOCKS BETWEEN CB & ISO
11. INTERLOCKS FOR LOCAL CLOSE OF CB
12. INTERLOCKS FOR REMOTE CLOSE OF CB
13. INTERLOCKS FOR ISOLATOR
14. INTERLOCKS FOR EARTH SWITCH
15. CB CLOSING CIRCUIT
16. CB TRIPPING CIRCUIT
17. WHAT IS BISTABLE RELAYS-NORMAL SWITCH
18. WHAT IS MONOSTABLE RELAYS-BELL SWITCH
19. ANTIPUMPING CONTACTOR
20. WHAT IS TSR & PRE CLOSE & POST CLOSE
21. AC FAIL CONTACTOR
22. DC FAIL CONTACTOR
23. SYNCHROSCOPE SOCKET – REQUIREMENTS – CONDITIONS
24. CB POLE DISCREPANCY RELAY
25. BINARY INPUT & BINARY OUTPUT OF RELAY
26. TNC SWITCH
27. LOCAL REMOTE SWITCH
28. SPRING CHARGE LIMIT SWITCH
29. TYPES OF WIRING- INTRA, INTER & CABLE SCHEDULE
30. PT / CVT IN MB
31. PT DISTRIBUTION
32. BUS PT SELCTION LOGIC
33. BUSPT LINE CVT SELECTOR SWITCH
34. CT IN MB & CORE CLASS & TERMINATION & STAR FORMATION FOR BUS & CIRCUIT
35. STANDARDS FOLLOWING
36. CABLE SCHEDULE

3. C & R Panel Contains
1. AC Circuits
2. DC Circuits
3. CT Circuits
4. PT/CVT Circuits

4. PURPOSE OF AC CIRCUITS
1. DOOR LAMP
2. PANEL HEATER
3. PLUG SOCKET
4. AUX SUPPLY TO ANNUNCIATION FACIA
5. AUXILIARY SUPPLY TO TRANSDUCER CKT
6. DC FAIL CIRCUIT
AC CIRCUITS are to be Extended to
1. Control Panel
2. Circuit Breaker Marshaling Box
3. Switch Yard Bay Marshalling Box
4. Current Transformer Marshalling Box
5. CVT / PT / EMVT Marshalling Box
6. ISOLATOR Operation (3-Ph)
7. Circuit Breaker Operating Mechanism Drive(3-Ph)

5. PURPOSE OF DC CIRCUITS
1. INDICATION CIRCUITS
2. ANNUNCIATION CIRCUITS
3. CB CLOSING COIL & TRIP COIL-1 CKT
4. CB TRIP COIL-2 CKT
5. TO SYNCHRONISATION CIRCUIT
6. TO MAIN-1(21M1/ 87T) PROTECTION
7. TO MAIN-2 or BU(21M2/ 67) PROTECTION
8. TO AC SUPERVISION
9. TO ISOLATOR CONTROL
10. TO ISOLATOR INTERLOCK

6. INDICATION CIRCUITS
1. CB 52 CLOSE & OPEN
2. CB 52 TC-1 HEALTHY
3. CB 52 TC-2 HEALTHY
4. CB 52 SPRING CHARGED
5. CB 52 CAPACITOR CHARGED
6. CB 52 SEMAPHORE INDICATIOR
7. BUS ISOLATOR 29/89 CLOSE & OPEN
8. BUS ISO 29/89 SEMAPHORE INDICATOR
9. LINE ISOLATOR 29/89L CLOSE & OPEN
10.LINE ISO 29/89L SEMAPHORE
INDICATOR

7. GROUP - A & GROUP - B TRIPPINGS
For 400KV Stations there shall be two separate Battery systems available for Protection, Control
& Tripping/Closing Operations. To obtain Redundancy and to be able to take Protection out for
Maintenance, while Equipment is in service, the Relays are Electrically and Physically
segregated in to two groups. Grouping is done to the extent possible in such a way that each
group can independently carryout Protective functions with near equal redundancy. Inter
connection of these two groups shall not be generally be attempted.
DISTRIBUTION OF DC SUPPLY SHALL BE DONE BAY WISE TO FEED THE FOLLOWING
1. PROTECTION
2. CB CONTROL
3. ISOLATOR / EARTH SWITCH CONTROL
4. ANNUNCIATION / INDICATION
LINE PROTECTION TRANSFORMER PROTECTION REACTOR PROTECTION
GROUP-A
MAIN-1 PROTECTION
M1 BUILT IN FUNCTIONS
TEED-1 PROTECTION
OVER VOLTAGE STAGE-1 PROT
DIRECT TRIP CHANNEL-1 RECEIVED
GROUP-B
MAIN-2 PROTCTION
M2 BUILT IN FUNCTIONS
TEED-2 PROTECTION
OVER VOLTAGE STAGE-2 PROT
LBB/BFR RELAY
DIRECT TRIP CHANNEL-2 RECEIVED
GROUP-A
T/F DIFFERENTIAL RELAY
T/F HV BACKUP RELAY
T/F IMP / 21T RELAY
T/F HV OVERFLUX RELAY
OIL TEMP HIGH TRIP
PRESURE RELIEF TRIP
TERITIARY DELTA WNDG NDR PROT
GROUP-B
T/F REF / HIGH Z DIFF RELAY
BUCHHOLZ TRIP
T/F LV BACKUP RELAY
T/F NEUTRAL CURRENT / 51 O/C RLY
T/F LV OVERFLUX RELAY
OVER LOAD PROT (ALARM ONLY)
OLTC BUCHHOLZ TRIP
WINDING TEMP HIGH TRIP
LOW/ HIGH OIL LEVEL TRIP
GROUP-A
REACTOR DIFFERENTIAL RELAY
REACTOR BACKUP / 21R RELAY
OIL TEMP HIGH TRIP
PRESURE RELIEF TRIP
GROUP-B
REACTOR REF RELAY
BUCHHOLZ TRIP
WINDING TEMP HIGH TRIP
LOW/ HIGH OIL LEVEL TRIP
FIRE PROTECTION TRIP

8. VOLTAGE SUPPLY SELECTION
BUS-1 BUS-2
89A 89B
52 CB
3
CT 89L
LINE
PT/EMVT PT/EMVT
WAVE TRAP
CVT LA/SA
IF 89A ISOLATOR CLOSED BUS-1 PT VOLTAGE WILL BE SELECTED
IF 89B ISOLATOR CLOSED BUS-2 PT VOLTAGE WILL BE SELECTED
IF VOLTAGE SELECTOR SWITCH IS KEPT IN BUS THEN BUS PT
VOLTAGE IS EXTENDED TO RELAY
IF VOLTAGE SELECTOR SWITCH IS KEPT IN LINE THEN LINE CVT
VOLTAGE IS EXTENDED TO RELAY
THE CIRCUIT DIAGRAM SHOWN IN NEXT PRESENTATION
BUS-1 & BUS-2 PT IS COMING TO PT DISTRIBUTION BOX AND
DISTRIBUTED FURTHER.

9. VOLTAGE SUPPLY SELECTION
89A
BUS-1 ISOLATOR
+VE
-VE
R
Y
B
N
BUS-1
PT
SUPPLY
89B
BUS-2 ISOLATOR
+VE
-VE
R
Y
B
N
BUS-2
PT
SUPPLY
89BX
89AX
R
Y
B
N
LINE
CVT
SUPPLY
BUS
PT
LINE
CVT
N
MANUAL
VOLTAGE
SELECTOR
SWITCH.
21 MAIN-1
OR
21 MAIN-2
PROT
RELAY

10. CT NAME PLATE DETAILS
CORE
CLASS OF
ACCURAC
Y
RATIO
PRIMAR
Y
WINDIN
G
SECONDA
RY
WINDING
KNEE
POINT
VOLTAGE
MAGNETISIN
G CURRENT
CORE
RESISTANC
E
1
PS
(PROTECT
ION)
500/1
PI – P2
1S1 – 1S2 1000V 120mA 2.5 OHMS
1000/1 1S1 – 1S3 2000V 60mA 5.0 OHMS
2000/1 1S1 – 1S4 4000V 30mA 10.0 OHMS
2
PS
(PROTECT
ION)
500/1
PI – P2
2S1 – 2S2 1000V 120mA 2.5 OHMS
1000/1 2S1 – 2S3 2000V 60mA 5.0 OHMS
2000/1 2S1 – 2S4 4000V 30mA 10.0 OHMS
3
0.2
(METERIN
G)
500/1
PI – P2
3S1 – 3S2
BURDEN = 40VA
1000/1 3S1 – 3S3
2000/1 3S1 – 3S4
4
PS
(PROTECT
ION)
500/1
PI – P2
4S1 – 4S2 1000V 120mA 2.5 OHMS
1000/1 4S1 – 4S3 2000V 60mA 5.0 OHMS
2000/1 4S1 – 4S4 4000V 30mA 10.0 OHMS
5
PS
(PROTECT
ION)
500/1
PI – P2
5S1 – 5S2 1000V 120mA 2.5 OHMS
1000/1 5S1 – 5S3 2000V 60mA 5.0 OHMS
2000/1 5S1 – 5S4 4000V 30mA 10.0 OHMS

11. CVT NAME PLATE DETAILS
CORE
CLASS OF
ACCURACY
PRIMARY
WINDING
SECONDAR
Y WINDING
PRIMARY
VOLTAGE
SECONDARY
VOLTAGE
VA BURDEN
1
3P
(PROTECTIO
N)
P1 – E
1a1 – 1n
1a2 – 1n
220KV / √3 110V / √3 200 VA
2
3P
(PROTECTIO
N)
P1 – E
2a1 – 2n
2a2 – 2n
220KV / √3 110V / √3 200 VA
3
0.2
(METERING)
P1 – E
3a1 – 3n
3a2 – 3n
220KV / √3 110V / √3 100 VA
CORE
CLASS OF
ACCURACY
PRIMARY
WINDING
SECONDAR
Y WINDING
PRIMARY
VOLTAGE
SECONDARY
VOLTAGE
VA BURDEN
1
3P
(PROTECTIO
N)
P1 – E
1a1 – 1n
1a2 – 1n
400KV / √3 110V / √3 200 VA
2
3P
(PROTECTIO
N)
P1 – E
2a1 – 2n
2a2 – 2n
400KV / √3 110V / √3 200 VA
3
0.2
(METERING)
P1 – E
3a1 – 3n
3a2 – 3n
400KV / √3 110V / √3 100 VA

12. PT / EMVT NAME PLATE DETAILS
CORE
CLASS OF
ACCURACY
PRIMARY
WINDING
SECONDAR
Y WINDING
PRIMARY
VOLTAGE
SECONDARY
VOLTAGE
VA BURDEN
1
0.2
(METERING)
P1 – E
1a1 – 1n
1a2 – 1n
132KV / √3 110V / √3 100 VA
2
0.5
(PROTECTIO
N)
P1 – E
2a1 – 2n
2a2 – 2n
132KV / √3 110V / √3 100 VA
3
3P
(PROTECTIO
N)
P1 – E
3a1 – 3n
3a2 – 3n
132KV / √3 110V / √3 100 VA
CORE
CLASS OF
ACCURACY
PRIMARY
WINDING
SECONDAR
Y WINDING
PRIMARY
VOLTAGE
SECONDARY
VOLTAGE
VA BURDEN
1
3P
(PROTECTIO
N)
P1 – E
1a1 – 1n
1a2 – 1n
220KV / √3 110V / √3 200 VA
2
3P
(PROTECTIO
N)
P1 – E
2a1 – 2n
2a2 – 2n
220KV / √3 110V / √3 200 VA
3 0.2 P1 – E
3a1 – 3n
3a2 – 3n
220KV / √3 110V / √3 100 VA

13. BUS PT AT YARD
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
BUS-1
PT/EMVT
PRIMARY
VOLTAGE
220
KV
/
1.732
SECONDARY
VOLTAGE
110V/1.732
P1
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
TO
CONTROL
ROOM
PT
DISTRIBUTION
PANEL
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
BUS-2
PT/EMVT
PRIMARY
VOLTAGE
220
KV
/
1.732
SECONDARY
VOLTAGE
110V/1.732
P1
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
U
TO
CONTROL
ROOM
PT
DISTRIBUTION
PANEL
BUS-1 BUS-2
METERING
CL:
0.2
MAIN-2
PROT
CL:3P
MAIN-1
PROT
CL:3P
OPEN
DELTA
CL:
0.5
METERING
CL:
0.2
MAIN-2
PROT
CL:3P
MAIN-1
PROT
CL:3P
OPEN
DELTA
CL:
0.5
PTMB PTMB

14. BUS PT DISTRIBUTION PANEL
(EXCEPT FOR 1-1/2CB / DBDCB / RING SYSTEM)
X02
1
2
3
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
9
10
11
12
13
14
X12 X22
1
2
3
4
5
6
7
8
9
10
11
12
13
14
51
52
53
54
55
56
57
58
59
60
61
62
63
64
X02
BUS-1 PT DISTRIBUTION BUS-2 PT DISTRIBUTION
TO INDIVIDUAL
C&R PANEL
EACH SET FOR
EACH CIRCUIT

15. PT/CVT & CT MARSHLING BOX
TB 1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
TB 2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
TB 3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
TB 4
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
TB 5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
TB 1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
TB 2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
TB 3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
CT MARSHELLING BOX CVT/PT MARSHELLING BOX
TB
6
1
2
3
4
5
6
7
8
9
10
TB
4
1
2
3
4
5
6
7
8
9
10

16. BAY MARSHLING BOX
TB 1
1
50
TB 2
51
100
TB 3
101
150
TB 4
151
200
TB 5
201
250
BAY MARSHELLING BOX BACK VIEW
TB DISTRIBUTION
BAY MARSHELLING BOX FRONT VIEW
AC DISTRIBUTION
MAIN
MCB
3-PH
100A
MCB
-1
3-PH
25A
MCB
-2
3-PH
25A
MAIN
- 3
3-PH
10A
MCB
- 4
3-PH
10A
MCB
- 5
3-PH
10A
MAIN
- 6
3-PH
10A
MCB
- 8
3-PH
10A
MAIN
- 9
3-PH
10A
MCB
- 10
3-PH
10A
MCB
- 11
3-PH
10A
MAIN
- 12
3-PH
10A
MCB
- 13
3-PH
10A
MAIN
- 1
1-PH
5A
MCB
- 2
1-PH
5A
MCB
- 3
1-PH
5A
MAIN
- 4
1-PH
5A
MCB
- 5
1-PH
5A

17. IMPORTANT GUIDELINES
CT & VT Earthing
 CT / VT secondary neutrals should be earthed at one
point only.
 VT secondary neutral earthing is done at equipment
itself.
 It is preferable to earth the CT secondary neutral in the
control / protection cubicle in order to provide
maximum security to the operating personnel.
CT POLARITY
 As a practice the P1 terminal of the CT shall be towards
the bus and P2 away from the bus.
 From the above for Main-1, Main-2 & Metering – Primary
current flows from P1 to P2. Accordingly secondary
current Flows S2 to S1. Star formation is all S2s.
 For the BBM & BBC – Primary current flows from P2 to
P1. Accordingly secondary current Flows S1 to S2. Star
formation is all S1s. Please conclude here.

18. CABLE SCHEDULE
CABLE SCHEDULE
1. NAME OF THE SUBSTATION: 2. NAME OF THE FEEDER/ TRANSFORMER:
3. CB DETAILS: 4. CT DETAILS
5. CVT / PT / EMVT DETAILS: 6. ISOLATOR DETAILS
7. C&R PANEL DETAILS: 8. POWER TRANSFORMER DETAILS :
S.No
FROM TO
DESCRIPTION / PURPOSE
CORE
NO
REFERENCE
PANEL TB No FERRULE PANEL TB No FERRULE
Cable
ID
Cable
& Size

19. CABLE SCHEDULE
1 2 3 4 5 6 7
S.No
FROM TO
PANEL TB No FERRULE PANEL TB No FERRULE
1
R – PH
CT
CORE
- 5
5S1
CTMB
TB-5-1 R-5S1
2 5S2 TB-5-2 R-5S2
3 5S3 TB-5-3 R-5S3
4 5S4 TB-5-4 R-5S4
5
Y – PH
CT
CORE
- 5
5S1
CTMB
TB-5-6 Y-5S1
6 5S2 TB-5-7 Y-5S2
7 5S3 TB-5-8 Y-5S3
8 5S4 TB-5-9 Y-5S4
9
Y – PH
CT
CORE
- 5
5S1
CTMB
TB-5-11 B-5S1
10 5S2 TB-5-12 B-5S2
11 5S3 TB-5-13 B-5S3
12 5S4 TB-5-14 B-5S4

20. CABLE SCHEDULE
8 9 10 11 12
DESCRIPTION /
PURPOSE
CABLE
& SIZE
CORE
No
REFERENCE REMARKS
R-PH CT TO
CT MB OF
CORE-5
4C X 2.5
1
DRG NO:
PAGE NO
2
3
4
Y-PH CT TO
CT MB OF
CORE-5
4C X 2.5
1
DRG NO:
PAGE NO
2
3
4
B-PH CT TO
CT MB OF
CORE-5
4C X 2.5
1
DRG NO:
PAGE NO
2
3
4

21. CIRCUIT BREAKER
S.No DESCRIPTION INCASE OF CGL BREAKER
1 LOCAL CLOSING INTERLOCK K5, K5A
2 LOCAL CLOSE (IN CB CUBICLE) - -
3 REMOTE CLOSE (FROM CONTROL PANEL HAND CLOSE) K1
4 LOCAL TRIP ( IN CB CUBICLE) - -
5 REMOTE TRIP COIL-1 (FROM CONTROL PANEL HAND TRIP) K21A, K21B, K21C
6 REMOTE TRIP COIL-2 (FROM CONTROL PANEL HAND TRIP) K41A, K41B, K41C
7 CB OPEN INDICATION A11, A12-B11,B12-C11,C12
8 CB CLOSE INDICATION A41, A42-B41,B42-C41,C42
9 DC SUPPLY J1, J2 & J11 & J12
10 PROTECTION CLOSE OR AUTO RE-CLOSE K3
11 PROTECTION TRIP COIL-1 & POST CLOSE SUPERVISION K23A, K23B, K23C
12 PROTECTION TRIP COIL-2 & POST CLOSE SUPERVISION K43A, K43B, K43C
13 PRE CLOSE SUPERVISION OF TRIP COIL-1 K31A, K31B, K31C
14 PRE CLOSE SUPERVISION OF TRIP COIL-2 K49A, K49B, K49C
15 CB CONTACT DICTRIBUTION. NOs – 8, NCs – 8
16 CB POLE DISTURBANCE RELAY.
17 CB CONTACT MULTIPLICATION RELAY.
18 CB TROUBLE ALARMS - 63 AR, GA, GL, AL, AG, AA, OA

22. CIRCUIT BREAKER CLOSING CIRCUIT
52CC
52b
J4
63A
63G
63HO
63N
SPL
52Y
J3
T N C
LCIL
K1 K3
LOCAL
REMOTE
K3A
K5
52Y
52Y
52Y
SLS
52a
86A 86B 96BB
T N C
SSSS
SERVICE
BYPASS
SSS REMOTE
CLOSE
21M1 A/R
21M2 A/R
A/R CLOSE
CONTROL & RELAY PANEL
A/R CLOSE
REMOTE CLOSE INTERLOCK

23. CIRCUIT BREAKER TRIPPING CIRCUIT
52TC
52a
J4
63A
63G
63HO
63N
J3
T N C
LOCAL
REMOTE
PRE
CLOSE
SUPERVISION
PROTECTION
TRIP
+
POST
CLOSE
SUPERVISION
PB
EMERGENCY TRIP
T N C
52TC
52a
J14
63A
63G
63HO
63N
PRE
CLOSE
SUPERVISION
PROTECTION
TRIP
+
POST
CLOSE
SUPERVISION
LOCAL
REMOTE
J13
C&R PANEL
T N C
PB
EMERGENCY TRIP

24. NOMINCLATURES
52
a
CB AUX CONTACT OPEN
WHEN CB OPEN
52b CB AUX CONTACT
CLOSE WHEN CB OPEN
52
CC
CB CLSOING COIL 52T
C-1
CB TRIP COIL-1
63
A
AIR PRESSURE
CONTACT
52
TC-
2
CB TRIP COIL-2
63
G
SF6 GAS PRESSURE
CONTACT
63
HO
HYDRAULIC OIL
PRESSURE CONTACT
63
N
NITROGEN PRESSURE
CONTACT
52Y ANTIPUMPING
CONTACTOR
SP
LS
SPRING CHARGE LIMIT
SWITCH
LCIL LOCAL CLOSING
INTERLOCK
K3
A
REMOTE CLOSE TNC TRIP NEUTRAL CLOSE
SWITCH
18
6
28
6
MONOSTABLE & SELF
RESETING
FAST ACTING HIGH
SPEED TRIP RELAYS
86 A
86 B
96
BB
BISTABLE & HAND
RESETING
HIGH SPEED TRIP
RELAY /
MASTER TRIP RELAYS
A/
R
AUTO RECLOSURE SSS
S
SYNCHROSCOPE
SELECTOR SWITCH
SS
S
SYNCHROSCOPE SOCKET PB PUSH BUTTON
LR LOCAL REMOTE SWITCH
Synchronization
Requirements
1. Voltages must be
match
2. Frequency must be
match
3. Phase angle must be
match
1. Line Voltage
2. Bus Voltage
3. DC Supply
4. Closing Permission

25. LOCAL CLOSING INTERLOCK
TAKE AN EXAMPLE OF SINGLE BUS SYSTEM
52 CB
BUS
89 / 29
89 / 29 E
89 / 29 L
89 / 29 LE
89 / 29 AE
LOCAL CLOSING INTERLOCK DRAWING
89M/B 89 E
89L 89AE
K1 K3
REQUIRED INTERLOCK
FOR LOCAL CLOSING
NORMALLY DURING
MAINTANENCE
1. BUS ISOLATOR OPEN CONDITION
2. LINE ISOLATOR OPEN CONDITION
3. 89E EARTH SWITCH CLOSED
4. 89AE EARTH SWITCH CLOSED

26. POLE DISTURBANCE RELAY
THIS RELAY COMES IN TO PICTURE THE CIRCUIT BREAKER 3POLES ARE INTER
CONNECTED THROUGH ELECTRICALLY NOT MECHANICALLY.
WHEN THREE POLES ARE SIMULTANEOUSLY NOT OPEN OR CLOSE THEN THE
RELAY ACTS AND TRIPS THE CIRCUIT BREAKER AFTER SOME TIME DELAY.
EXAMPLE: 220KV CB, 400KV CB, 765KV CB AND ABOVE VOLTAGE LEVEL
R Y B 52a
R Y B 52b
+VE
TIME DELAY
RELAY
TO
SER
TO
ANNUN
TO
CB
TRIP
-VE
52 TC-1-R
52 TC-1-Y
52 TC-1-B
52 TC-2-R
52 TC-2-Y
52 TC-2-B
-VE
52 CIRCUIT BREAKER

27. TRIP CIRCUIT HEALTHY
TO TC-1 HEALTHY INDICATION
TO TC-1 FAULTY ANNUNCIATION
+VE
TO CB PROTECTION TRIP
+ POST CLOSE SUPERVISION
PRE CLOSE SUPERVISION
CONTROL & RELAY PANEL CIRCUIT BREAKER CENTRAL MB
52 TC-1
-VE
CB HEALTHYNESS
TO TC-2 HEALTHY INDICATION
TO TC-2 FAULTY ANNUNCIATION
+VE
TO CB PROTECTION TRIP
+ POST CLOSE SUPERVISION
PRE CLOSE SUPERVISION
52 TC-2
-VE
CB HEALTHYNESS
TSR
TSR
LED
LED
52b
52b

28. MAIN-1 PROTECTION OPERATED
21 MAIN-1
BINARY OUTPUT
TO LBB
TO TC-1
TO TC-2
TO LBB
TO TC-1
TO TC-2
TO TC-1
TO TC-2
TO TC-1
TO TC-2
TO LBB
TO TC-1
TO TC-2
TO TC-1
TO TC-2
+VE -VE
R PHASE
Y PHASE
B PHASE
186 R1
186 R2
186 Y1
186 Y2
186 B1
186 B2

29. MAIN-2 PROTECTION OPERATED
21 MAIN-2
BINARY OUTPUT
TO LBB
TO TC-1
TO TC-2
TO LBB
TO TC-1
TO TC-2
TO TC-1
TO TC-2
TO TC-1
TO TC-2
TO LBB
TO TC-1
TO TC-2
TO TC-1
TO TC-2
+VE -VE
R PHASE
Y PHASE
B PHASE
286 R1
286 R2
286 Y1
286 Y2
286 B1
286 B2

30. 86 GA (MASTER TRIP RELAY) OPERATION
21 MAIN-1
TO ANN
+VE
-VE
RESET
OPERATED
PB
TO CL I/L
TO LBB
TO TC-1
TO TC-2
TO M1 DR
TO M2 DR
TO SER
86 GA MASTER TRIP RELAY
M1 BUILT IN
FUNCTIONS
TEED-1 PROTECTION
OVER VOLTAGE
STAGE-1 PROT
DIRECT TRIP
CHANNEL-1
RECEIVED

31. 86 GB (MASTER TRIP RELAY) OPERATION
21 MAIN-2
TO ANN
+VE
-VE
RESET
OPERATED
PB
TO CL I/L
TO LBB
TO TC-1
TO TC-2
TO M1 DR
TO M2 DR
TO SER
86 GB MASTER TRIP RELAY
M2 BUILT IN
FUNCTIONS
TEED-2
PROTECTION
OVER VOLTAGE
STAGE-2 PROT
LBB/BFR RELAY
DIRECT TRIP
CHANNEL-2
RECEIVED

32. 87 BUSBAR-1 PROTECTION
TRIPPING SCHEME
HIGH SPEED
TRIP RELAY
(96BB) FOR
BAY1
HIGH SPEED
TRIP RELAY
(96BB) FOR
BAY2
HIGH SPEED
TRIP RELAY
(96 BB) FOR
BAY3
HIGH SPEED
TRIP RELAY
(96 BB) FOR
BAY4
HIGH SPEED
TRIP RELAY
(96BB)FOR
BAY5
HIGH SPEED
TRIP RELAY
(96 BB) FOR
BAY6
BAY1 CR PANEL
TRIP FROM 50 LBB
TO START 50 LBB
BAY2 CB PANEL
TRIP FROM 50 LBB
TO START 50 LBB
BAY3 CB PANEL
TRIP FROM 50 LBB
TO START 50 LBB
BAY4 CB PANEL
TRIP FROM 50 LBB
TO START 50 LBB
BAY5 CB PANEL
TRIP FROM 50 LBB
TO START 50 LBB
BAY6 CB PANEL
TRIP FROM 50 LBB
TO START 50 LBB
+VE
BUSBAR PANEL
87 BUSBAR

33. 96 BB (MASTER TRIP RELAY) OPERATION
87 BUSBAR
TO D/T-1
+VE
-VE
RESET
OPERATED
PB
TO CL I/L
TO LBB
TO TC-1
TO TC-2
TO M1 DR
TO M2 DR
TO D/T-2
96 BB MASTER TRIP RELAY
TO ANNUN
TO SER
FROM LBB

34. TRANSFORMER TROUBLES TRIPPING
GR-A
OIL TEMP TRIP
BUCHHOLZ TRIP
PRD-1 TRIP
PRD-2 TRIP
DIFF RELAY 87T
OL RELAY 51OL
HV O/L+E/F PROT 67
86 AX
86 AY
TO 3PH GR-A 400KV MAIN
TO 3PH GR-A 220KV MAIN
NDR RELAY 151N
HV O/F RELAY 99T
+VE
+VE
-VE

35. TRANSFORMER TROUBLES TRIPPING
GR-B
REF RELAY 64REF
STUB RELAY 50ST
LV O/L+E/F PROT 67
86 BX
86 BY
TO 3PH GR-B 400KV MAIN
TO 3PH GR-B 220KV MAIN
LV O/F RELAY 99T
OLTC BUCHHOLZ-R TRIP
OLTC BUCHHOLZ-Y TRIP
OLTC BUCHHOLZ –B TRIP
WNDG TEMP-HV TRIP
WNDG TEMP-LV TRIP
WNDG TEMP-IV TRIP
+VE
+VE
-VE

36. LBB Operation & Output
INITIATION
186 R
186 Y
186 B
286 R
286 Y
286 B
86 GR-A
86 GR-B
96 BB
+VE
TO D/T CH-1
TO D/T CH-2
TO ANNUN
TO MAIN1 DR
TO MAIN2 DR
TO SER
TO 86 GR-A
TO 86 GR-B
TO BUSBAR
-VE
50X
LBB / BFR
TIMER

37. TRIP COIL-1 CIRCUITS
186R1
186R2
286R1
286R2
86GR-A
86GR-B
96BB
186Y1
186Y2
286Y1
286Y2
186B1
186B2
286B1
286B2
186R1, 186R2, 186Y1, 186Y2, 186B1, 186B2
ARE CB 1-PH TRIP UNIT OF GR-A. THESE
ARE SELF RESETING.
286R1, 286R2, 286Y1, 286Y2, 286B1, 286B2
ARE CB 1-PH TRIP UNIT OF GR-B. THESE
ARE SELF RESETING.
THE BELOW ARE HAND RESETING.
86GR-A, 86GR-B ARE 3-PH TRIP UNITS.
96 BB IS BUSBAR TRIPPING RELAY
TRIP COIL-1

38. TRIP COIL-2 CIRCUITS
186R1
186R2
286R1
286R2
86GR-A
86GR-B
96BB
186Y1
186Y2
286Y1
286Y2
186B1
186B2
286B1
286B2
186R1, 186R2, 186Y1, 186Y2, 186B1, 186B2
ARE CB 1-PH TRIP UNIT OF GR-A. THESE
ARE SELF RESETING.
286R1, 286R2, 286Y1, 286Y2, 286B1, 286B2
ARE CB 1-PH TRIP UNIT OF GR-B. THESE
ARE SELF RESETING.
THE BELOW ARE HAND RESETING.
86GR-A, 86GR-B ARE 3-PH TRIP UNITS.
96 BB IS BUSBAR TRIPPING RELAY
TRIP COIL-2

39. CB CONTACT MULTIPLICATION
S.No R-PHASE Y-PHASE B- PHASE REF PURPOSE A-POLE B-POLE C-POLE
1 A11,A12 B11,B12 C11,C12
2 A13,A14 B13,B14 C13,C14
3 A15,A16 B15,B16 C15,C16
4 A17,A18 B17,B18 C17,C18
5 A19,A20 B19,B20 C19,C20
6 A21,A22 B21,B22 C21,C22
7 A23,A24 B23,B24 C23,C24
8 A25,A26 B25,B26 C25,C26
9 A41,A42 B41,B42 C41,C42
10 A43,A44 B43,B44 C43,C44
11 A45,A46 B45,B46 C45,C46
12 A47,A48 B47,B48 C47,C48
13 A49,A50 B49,B50 C49,C50
14 A51,A52 B51,B52 C51,C52
15 A53,A54 B53,B54 C53,C54
16 A55,A56 B55,B56 C55,C56

40. PROTECTION COUPLER PANEL
C
E
DISPLAY
ACTIVE START TRIP
NSD 50/
NSD 70
G4AC TB: V9LC
1-
2+
5-
6+
9-
10+
13-
14+
TX
TRIP
A(C)
RX
TRIP
A(C)
TX
TRIP
B(D)
RX
TRIP
B(D)
C
S
C
S
C
R
C
R
GA4D TB:V9LD
1-
2+
5-
6+
9-
10+
13-
14+
TX
TRIP
C(A)
RX
TRIP
C(A)
TX
TRIP
D(B)
RX
TRIP
D(B)
C
S
C
S
C
R
C
R
G4AA TB: V9LB
ALARM-1
250V
DC
ALARM-2
250V
DC
5
6
7
8

41. PROTECTION COUPLERS FOR 400KV LINE
 FOR EACH LINE 2Nos PROTECTION COUPLER PANELS PROVIDED.
 FOR EACH LINE 1NO CARRIER SPEECH PANEL PROVIDED.
 SO, ONE LINE REQUIRES TOTAL 3 PANELS.
 CARRIER SPEECH PANEL PURELY FOR VOICE COMMUNICATION BETWEEN
TWO SUBSTATIONS, i.e THE LINE CONNECTED SUBSTATIONS.
 THE VOICE COMMUNICATION ARE TWO METHODS PROVIDED.
 ONE IS HOTLINE COMMUNICATION/DEDICATED/ LIFT&TALK METHOD.
 ANOTHER IS DIAL METHOD.
 IN PROTECTION COUPLER PANEL-1 TOTAL 3 CARDS ARE IMPORTANT FOR
SENDING & RECEIVING TRIP SIGNALS.
 ONE CARD FOR ALARM i.e G4AA. ONE CARD FOR PERMISSIVE/PROTECTION
TRIP i.e G4AC & ANOTHER CARD FOR DIRECT TRIPS i.e G4AD.
 IN PROTECTION COUPLER-2 PANEL ALSO 3 CARDS ARE PROVIDED SIMILAR TO
PROTECTION COUPLER-1 PANEL.
 THE PROTECTION COUPLER PANEL DRAWING IS SHOWN IN PREVIOUS MENU.
 1SET TX & RX FOR PERMISSIVE/ PROTECTION TRIP(G4AC)
 1SET TX & RX FOR BACKUP FOR PERMISSIVE/ PROTECTION IN ANOTHER
PANEL(G4AC).
 1SET TX & RX FOR DIRECT TRIP CHANNEL-1( G4AD).
 1SET TX & RX FOR SPARE UNDER EMERGENCY(G4AD).
 THE ABOVE ARRANGEMENT SIMILAR FOR PROTECTION COUPLER PANEL-2.
 G4AA CARD FOR ALARM.

42. MAIN-1 PROTECTION CARRIER INTER TRIPPING
ABB REL521
CR
CS
-VE
CARRIER RECEIVE
CARRIER SEND
ALARM
IN
ABB
NSD
50
OUT
PANEL-1
PANEL-2
G4AC V9LC 1
G4AC V9LC 2
G4AC V9LC 5
G4AC V9LC 6
G4AA V9LB 5
G4AA V9LB 6
ABB
NSD
50
G4AC V9LC 10
G4AC V9LC 14
G4AC V9LC 9
G4AC V9LC 13
THIS IS BACKUP FOR PERMISSIVE/ PROTECTION TRIP
AND CONNECTED IN ANOTHER PANEL
+VE -VE

43. MAIN-2 PROTECTION CARRIER INTER TRIPPING
ABB REL316
CR
CS
-VE
CARRIER RECEIVE
CARRIER SEND
ALARM
IN
ABB
NSD
50
OUT
PANEL-2
PANEL-1
G4AC V9LC 1
G4AC V9LC 2
G4AC V9LC 5
G4AC V9LC 6
G4AA V9LB 5
G4AA V9LB 6
ABB
NSD
50
G4AC V9LC 10
G4AC V9LC 14
G4AC V9LC 9
G4AC V9LC 13
THIS IS BACKUP FOR PERMISSIVE/ PROTECTION TRIP
AND CONNECTED IN ANOTHER PANEL
+VE -VE

44. DIRECT TRIP SEND CARRIER CHANNEL-1
T N C
MAIN CB(1-52CB)
CONTROL PANEL
87 BUSBAR TRIP (ZONE-1)
50 LBB/BFR
ABB
NSD 50
DC +VE
FROM PANEL
G4AD V9LC 2
DC –VE FROM PANEL
G4AD V9LC 1
PANEL-1
BUSBAR PROTECTION PANEL
RELAY PANEL
.
OVER VOLTAGE STAGE 1 or 2

45. DIRECT TRIP SEND CARRIER CHANNEL-2
T N C
MAIN CB(1-52CB)
CONTROL PANEL
87 BUSBAR TRIP (ZONE-1)
50 LBB/BFR
ABB
NSD 50
DC +VE
FROM PANEL
G4AD V9LC 2
DC –VE FROM PANEL
G4AD V9LC 1
PANEL-2
BUSBAR PROTECTION PANEL
RELAY PANEL
.
OVER VOLTAGE STAGE 1 or 2

46. DIRECT TRIP RECEIVE CHANNEL-1&2
ABB
NSD 50
G4AD V9LC 6
G4AD V9LC 5
ABB
NSD 50
G4AD V9LC 6
G4AD V9LC 5
PANEL-1
PANEL-2
DC +VE
DC +VE
+VE -VE
TO 86-A MASTER TRIP RELAY
(HIGH SPEED TRIP RELAY)
TO 86-B MASTER TRIP RELAY
(HIGH SPEED TRIP RELAY)
DIRECT TRIP-1
CARRIER RECEIVE
RELAY
DIRECT TRIP-2
CARRIER RECEIVE
RELAY
TO ANNUNCIATION
TO MAIN1 DR
TO MAIN2 DR
TO ANNUNCIATION
TO MAIN1 DR
TO MAIN2 DR