GE 339

CHAPTER 6: SETPOINTS S3 PROTECTION
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 6–65
Figure 6-28: Neutral Instantaneous Overcurrent logic diagram
SETTING
RUN
SETTING
SETTING
NEUTRAL IOC FUNCTION
NEUTRAL IOC DIRECTION
Disabled = 0
Forward
Latched Alarm
Disabled
NEUTRAL IOC DELAY
Alarm
Reverse
Current in Reverse
From NEUTRAL DIRECTIONAL
Current OK
Trip
SETTING
BLOCK 1: Off = 0 BLOCK 2: Off = 0 BLOCK 3: Off = 0
SETTING
NEUTRAL IOC ALARM PKP
t
PKP
S R
LATCH
896830A2.cdr
LOGIC OPERAND
NEUTRAL IOC ALARM OP
LOGIC OPERAND
OR
OR
AND
AND
AND
AND
AND
AND
OR
AND
AND
INPUTS
Emergency Restart Input Lockout Reset Input
SETTINGS
Off = 0 Lockout Reset Off = 0
Emergency Restart
S4 CONTROLS
NEUTRAL IOC Alarm State: Operate
TARGET MESSAGE
ANY ALARM OP
NEUTRAL IOC TRIP OP
ANY TRIP OP
S R
LATCH
NEUTRAL IOC Trip State: Operate
TARGET MESSAGE
ANY ALARM PKP NEUTRAL IOC TRIP PKP ANY TRIP PKP
AND AND
OR
S3 NEUTRAL IOC
S3 NEUTRAL IOC
S3 NEUTRAL IOC
S3 NEUTRAL IOC
S3 NEUTRAL IOC
OR
Reset Input
Reset Off = 0
AND
OR
KEYPAD RESET
ANY LATCHED ALARM OP
NEUTRAL IOC State: Pickup
Alarm
TARGET MESSAGE
NEUTRAL IOC State: Pickup
Trip
0
IN > PICKUP
NEUTRAL IOC PKP
Neutral Current (IN)
Control
AND
LEI PKP
AND
LEI OP
OUTPUT RELAY X
SETTING
Do Not Operate, Operate