GE 350-A9

6–90 350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION CHAPTER 6: SETPOINTS
Figure 6-40: Overfrequency logic diagram
Phase Voltage Inputs
(associated setpoints)
SETPOINT
Vab
SETPOINT
OVERFREQ FUNCTN: Disabled = 0
Latched Alarm
OVERFREQ PKP:
Vbc Vca
Operate Output Relay 1 (TRIP)
Event Recorder
Transient 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
Van Vbn
Vcn
AND
DeltaWye
LED: PICKUP
Event Recorder
Transient Recorder
Overfrequency1(2)
Message
f > PICKUP
Frequency
Measurement
f ( Va) - frequency
OVERFREQ DELAY:
SETPOINT
t
PKP
LED: ALARM
RESET
Command
AND
S R
LATCH
898002A1.cdr
Va < 0.3 x VT