GE 339

CHAPTER 6: SETPOINTS S3 PROTECTION
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 6–75
Figure 6-30: Neutral Timed Overcurrent Protection: Logic Diagram
SETPOINTS
Neutral current (IN)
RUN
SETPOINTS
BLOCK 1: Off = 0
NTRL TOC PICKUP: NTRL TOC CURVE: NTRL TOC TDM:
IN > PICKUP
BLOCK 2: Off = 0 BLOCK 3: Off = 0
OR
AND
Operate Output Relay 1 (TRIP)
Event Recorder
Transient Recorder
NTRL TOC PKP
LED: TRIP
Event Recorder
Transient Recorder
OR
OR
NTRL TOC OP
Adjust PKP
Cold Load PKP
Computed by the relay
Adjust Neutral TOC PKP
AND
SETPOINTS:
Do Not Operate, Operate
OUTPUT RELAY X
AND
Trip (To Breaker Failure)
NTRL TOC RESET:
SETPOINTS
NTRL TOC DIRECTION: Forward Disabled Reverse
SETPOINT
NTRL TOC FUNCTION: Disabled = 0
Latched Alarm Alarm
Trip
Autoreclose
(per shot settings)
LED: ALARM
RESET
Command
AND
S R
LATCH
LED: PICKUP
Message:
898008A2.cdr
AND AND
NRL DIR REV
From NEUTRAL DIRECTIONAL
NRL DIR FWD
OR
BLK NTRL DIR OC UND
AND