7–8
345 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
M3 BREAKER MAINTENANCE
CHAPTER 7: MAINTENANCE
Figure 4: Trip coil monitoring logic diagram
SETPOINT
TRIP
COIL
FUNCTION:
Disabled
=
0
Latched
Alarm
Event
Recorder
T
ransient
Recorder
Alarm
OR
OR
AND
SETPOINT
:
Operate
output
relays
upon
selection
OUTPUT
RELA
Y
4
OUTPUT
RELA
Y
5
OUTPUT
RELA
Y
6
OUTPUT
RELA
Y
3
T
rip
Coil
Montr
OP
Message
T
rip
Coil
current
above
threshold
AND
OR
52a/b
INPUTS
Breaker
Closed
T
rip
From
output
relay
1(2)
SETPOINT
BYP
ASS
BKR
ST
A
T
E
Enabled
=
1
Disable
=
0
AND
TRIP
COIL
DELA
Y
:
SETPOINT
t
PKP
LED:
MAINTENANCE
T
rip
Coil
Montr
PKP
Message
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
898020.cdr