GE 350-A9

CHAPTER 6: SETPOINTS S3 PROTECTION
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL 6–105
Figure 6-46: Broken conductor logic diagram
SETPOINT
= Disabled
= Alarm
FUNCTION
= Latched Alarm
= Control
=Trip
LED: ALARM
OR
Volatile, Reset-dominant
Latch
S R
AND AND
RESET
Command
AND
LED: TRIP
Operate Output Relay 1 (TRIP) Trip (to Breaker Failure)
OR
SETPOINTS
=On
BLOCK 1:
=On
BLOCK 2:
=On
BLOCK 3:
OR
AND
SETPOINTS
RUN
I-1 MAX: |I_1/I_2| > I_2/I_1 RATIO
AND
SETPOINT PICKUP DELAY:
0
T
PKP
SETPOINTS
OUTPUT RELAY X
Do Not Operate, Operate
LED: PICKUP
Message Event Recorder
Transient Recorder
Message
Event Recorder
Transient Recorder
I_1 MIN: I_2/I_1 RATIO: |I_1| > I_1 MIN |I_1| < I_1 MAX SETPOINTS
RUN
|IA| < I_1 MIN I_1 MIN |IB| < I_1 MIN |IC| < I_1 MIN |IA’| - |IA| > 0.05 x CT |IB’| - |IB| > 0.05 x CT |IC’| - |IC| > 0.05 x CT
Phase A current (IA)
Current Inputs
Phase B current (IB) Phase C current (IC) Pos Seq current (I_1)
Calculated by relay
Neg Seq current (I_2)
I’ is 4 cycles old
AND AND AND
OR
0
2 cyc
OR
898854A1.cdr