Schweitzer Engineering Laboratories SEL-421-4 - Figure 2.55 Typical External AC;DC Connections-Single Circuit Breaker

2.51
Date Code 20171021 Instruction Manual SEL-421 Relay
Installation
AC/DC Connection Diagrams
Figure 2.55 Typical External AC/DC Connections—Single Circuit Breaker
52
Circuit
Breaker
Synch Check
I POL
IAX
VAZ
ICW
IBW
IAW
VCY VBY VAY
A
BUS
SEL-421 Relay
B
C
LINE
Forward Direction
Trip Coil
52A1
OUT101
(+)
(—)
Breaker 1
Trip
Circuit
TC
Close Coil
52B1
OUT102
(+)
(—)
Breaker 1
Close
Circuit
CC
Lock Out
86B1
OUT103
(+)
(—)
Breaker
Failure
Trip
Circuit
86
OUT108
(+)
Alarm to
Annunciator, RTU,
or SEL-2020/2030
IN101
(+)
(—)
(+)
(—)
(+)
(—)
(+)
(—)
(—)
IN102
52A1
Breaker Status 1
Breaker
Failure Lock Out
PowerPower
Vdc1
Vdc2
Monitor Vdc1
(Station Battery)
Monitor Vdc2
(Trip Circuits,
Comms)
BF LO
(+)