GE Multilin 345 - Page 189

CHAPTER 6: SETPOINTS S3 PROTECTION
345 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 6–73
Figure 6-30: Neutral Timed Overcurrent Protection logic diagram
SETPOINTS
RUN
SETPOINT
NTRL TOC FUNCTION Disabled = 0
Alarm
NTRL TOC PICKUP NTRL TOC CURVE NTRL TOC TDM
IN > PICKUP
AND
LED: PICKUP
Latched Alarm
OR
Trip
NTRL TOC RESET
SETPOINTS
BLOCK 1 Off = 0 BLOCK 2 Off = 0 BLOCK 3 Off = 0
OR
NTRL TOC CT INPUT
Message and Event Recorder
NTRL TOC PKP
LED: TRIP
OR
AND AND
To Breaker Failure
Trip
Message and Event Recorder
LED: ALARM
RESET
Command
AND
S R
LATCH
NTRL TOC OP
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
897812A1.cdr
SETPOINTS:
Do Not Operate, Operate
OUTPUT RELAY X