Schweitzer Engineering Laboratories SEL-421-4 - Figure 2.56 Typical External AC;DC Connections-Dual Circuit Breaker

2.52
SEL-421 Relay Instruction Manual Date Code 20171021
Installation
AC/DC Connection Diagrams
Figure 2.56 Typical External AC/DC Connections—Dual Circuit Breaker
Circuit
Breaker 1
Circuit
Breaker 2
ICW
IBW
IAW
IAX
IBX
ICX
BK1 CTs
BK2 CTs
LINE PTs
A
BUS 1
SEL-421 Relay
B
C
A
BUS 2
B
C
A
B
C
LINE
Forward Direction
Synchronism-Check
Circuit Breaker 1
VAZ
PT Send
DTT Send
OUT104
(+)
(—)
Permissive
Trip Send
(to Comm.
Transmitter)
(+)
(—)
Direct Transfer
Trip Send
OUT105
Alarm to
Annunciator, RTU,
or SEL-2020/2030
(+)
OUT108
Trip Coil
52A1
OUT101
(+)
(—) Breaker 1
Trip Circuit
TC
Close Coil
52B1
OUT102
(+)
(—) Breaker 1
Close Circuit
CC
Lock Out
86B1
OUT103
(+)
(—) Bus 1
Breaker Failure
Trip Circuit
86
Trip Coil
52A2
OUT201
(+)
(—) Breaker 2
Trip Circuit
TC
Close Coil
52B2
OUT202
(+)
(—) Breaker 2
Close Circuit
CC
Lock Out
86B2
OUT203
(+)
(—) Bus2
Breaker Failure
Trip Circuit
86
Synchronism-Check
Circuit Breaker 2
VBZVCYVBYVAY
(+)
(—)
PowerPower
(+)
(—)
Vdc1
Monitor Vdc1
(Station Battery)
(+)
(—)
Vdc2
Monitor Vdc2
(Trip Circuits,
Comms)
IN101
(+)
(—)
52A1
Breaker Status 1
(—)
IN102
Bus 1
Breaker Failure
Lock Out
BF LO
(+)
IN103
(+)
(—)
PT RX
Permissive Trip
Receive
(—)
IN104
Direct Transfer
Trip Receive
DTT RX
(+)
IN201
(+)
(—)
52A2
Breaker Status 2
(—)
IN202
Bus 2
Breaker Failure
Lock Out
BF LO
(+)
52-1
52-2