6–46 345 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION CHAPTER 6: SETPOINTS
Figure 6-21: Instantaneous Differential Protection logic diagram
SETPOINT
SETPOINT
INST DIFF FUNCTION:
Disabled = 0
Latched Alarm
INST DIFFERENTIAL
PICKUP:
AND
Operate Output Relay 1 (W1 BKR TRIP)
LED: TRIP
Alarm
OR
AND
Trip
AND
SETPOINT
BLOCK 1:
Off = 0
BLOCK 2:
Off = 0
BLOCK 3:
Off = 0
OR
OR
Trip
(To Breaker Failure)
Phase A Diff current (IAd)
Phase B Diff current (IBd)
Phase C Diff current (ICd)
Phase Differential Currents
INST DIFF PKP
Message
LED: PICKUP
IAd = Pickup
IBd = Pickup
ICd = Pickup
RUN
RUN
RUN
INST DIFF OP
Event Recorder
OR
LED: ALARM
RESET
Command
AND
S
R
LATCH
Operate Output Relay 2 (W1 BKR TRIP)
SETPOINT
Do Not Operate, Operate
OUTPUT RELAY X
INST DIFF PKP
INST DIFF OP
897804A1.cdr
To Next Page
Loading...
