GE 350-A9

CHAPTER 6: SETPOINTS S3 PROTECTION
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL 6–75
Figure 6-32: Phase undervoltage logic diagram
Phase Voltage Inputs
(associated setpoints)
SETPOINTS
Vab
SETPOINT
PH UV FUNCTION: Disabled = 0
Latched Alarm
PH UV PICKUP: PH UV CURVE: PH UV DELAY:
AND
Vbc Vca
Operate Output Relay 1 (TRIP)
Event Recorder
LED: TRIP
Alarm
OR
OR
AND
SETPOINTS
Do Not Operate, Operate
OUTPUT RELAY X
Trip
AND
Trip (To Breaker Failure)
SETPOINTS
BLOCK 1: Off = 0 BLOCK 2: Off = 0 BLOCK 3: Off = 0
OR
RUN RUN RUN
PICKUP
Van Vbn
Vcn
None
PICKUP
PICKUP
Van or Vab > Minimum
Vbn or Vbc > Minimum
Vcn or Vca > Minimum
PH UV MIN VOLTAGE:
SETPOINT
AND
AND
AND
DeltaWye
All Three
Any One
Any Two
Operate for
programmed
combination
Any Two Any One
All Three
Pickup for
Programmed
Combination
SETPOINT
PH UV PHASES:
OR OR
LED: PICKUP
Phase Undervoltage
Message
LED: ALARM
RESET
Command
AND
S R
LATCH
898014A2.cdr