GE Multilin 345 - Page 191

CHAPTER 6: SETPOINTS S3 PROTECTION
345 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 6–75
BLOCK 1/2/3
For details see Common setpoints
.
Figure 6-31: Neutral Instantaneous Overcurrent Protection logic diagram
SETPOINTS
RUN
SETPOINT
NTRL IOC FUNCTION Disabled = 0
Latched Alarm
NTRL IOC PICKUP
IN > PICKUP
AND
LED: PICKUP
Alarm
OR
Trip
SETPOINTS
BLOCK 1 Off = 0 BLOCK 2 Off = 0 BLOCK 3 Off = 0
OR
NTRL IOC CT INPUT
Message and Event Recorder
NTRL TOC PKP
LED: TRIP
OR
AND
SETPOINTS
Do Not Operate, Operate
OUTPUT RELAY X
AND
To Breaker Failure
Trip
Message and Event Recorder
LED: ALARM
RESET
Command
AND
S R
LATCH
Neutral IOC PKP
SETPOINTS
(configurable only if “TRIP”
function selected)
Operate trip output relays upon selection
RLY 1 TRIP W1 BKR
Neutral current (IN)
CT(W2), CT(W2)
neutral current
computed by the relay
RLY 2 TRIP W2 BKR
897813A1.cdr
SETPOINTS
t
PKP
NTRL IOC PKP DELAY
0