CHAPTER 6: SETPOINTS
S3 PROTECTION
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–81
Figure 6-35: Negative Sequence Overvoltage logic diagram
Calculated Negative
Sequence V
oltage
SETPOINTS
SETPOINT
NEG SEQ OV FUNCTN:
Disabled = 0
Latched
Alarm
NEG SEQ OV PICKUP:
AND
Operate Output Relay 1 (TRIP)
Event Recorder
LED:
TRIP
Alarm
OR
OR
AND
SETPOINTS:
Do Not Operate, Operate
OUTPUT
RELA
Y X
Trip
AND
Trip (T
o Breaker Failure)
SETPOINTS
BLOCK 1:
Of
f = 0
BLOCK 2:
Of
f = 0
BLOCK 3:
Of
f = 0
OR
RUN
V_2
Phase VT
connection
Delta
Wye
LED: PICKUP
NegSeq Overvoltage
Message
V_2 or
3
*V_2
> PICKUP
NEG SEQ OV DELA
Y:
SETPOINT
t
PKP
3 * V_2
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
898016A2.cdr