7–6
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
M3 BREAKER MAINTENANCE
CHAPTER 7: MAINTENANCE
Figure 4: Trip coil monitoring logic diagram
Close coil
Close coil monitoring is performed by a built-in voltage monitor on the Form A output relay:
#2 Close. The voltage monitor is connected across the Form A contact, and effectively the
relay detects healthy current through the circuit. To do that, an external jumper should be
made between terminals “B4”, and “B5” for Close coil monitoring.
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
TRIP
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