GE 350-A9

CHAPTER 6: SETPOINTS S4 CONTROLS
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL 6–151
Figure 6-63: Second harmonic inhibit logic diagram
LED: PICKUP
SETPOINT
FUNCTION : Disabled = 0 Alarm Latched Alarm Control
OR
SETPOINT
2nd HRMC PICKUP : HM2A ≥PICKUP RUN
SETPOINT
2nd HRMC DELAY : t
PKP
0
Hrmc 2nd OP
Hrmc 2nd PKP
AND AND
Command
RESET
OR
LED: ALARM
SETPOINT
MINIMUM OPER CURRENT : IA ≥MINIMUM RUN
S
LATCH
Set-
Dominant
R
Phase A Current (IA) Phase B Current (IB)
Phase C Current (IC)
Phase A HM 2nd (HM 2A) Phase B HM 2nd (HM 2B)
Phase C HM 2nd (HM2C)
IB ≥MINIMUM IC ≥MINIMUM
HM2B ≥PICKUP RUN HM2C ≥PICKUP RUN
SETPOINT
OUTPUT RELAY X
Average HM 2nd (HM2avg )
Average Current (Iavg)
Iavg ≥MINIMUM
HM2avg ≥PICKUP RUN
SETPOINT
PHASES FOR OPERATION : ANY ONE : At least one phase picked up ; ANY TWO: Two or more phases picked up; ALL THREE: All three phases picked up; AVERAGE: Average value picked up.
Phase Currents
Second Harmonic Ratios
Message Event Recorder Transient Recorder Message Event Recorder Transient Recorder
Do Not Operate, Operate
898855A1.cdr