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
:
HM
2A
≥
PICKUP
RUN
SETPOINT
2nd HRMC DELA
Y
:
t
PKP
0
Hrmc
2nd OP
Hrmc
2nd PKP
AND
AND
Command
RESET
OR
LED
:ALARM
SETPOINT
MINIMUM OPER CURRENT
:
IA
≥
MINIMUM
RUN
S
LA
TCH
Set
-
Dominant R
Phase
A Current
(IA
)
Phase B Current
(IB
)
Phase C Current
(IC
)
Phase
A HM
2n
d
(HM
2A
)
Phase B HM
2n
d
(HM
2B
)
Phase C HM
2n
d
(HM
2C
)
IB
≥
MINIMUM
IC
≥
MINIMUM
HM
2B
≥
PICKUP
RUN
HM
2C
≥
PICKUP
RUN
SETPOINT
OUTPUT
RELA
Y
X
A
verage HM
2n
d
(HM
2avg
)
A
verage Current
(Iavg
)
Iavg
≥
MINIMUM
HM
2avg
≥
PICKUP
RUN
SETPOINT
PHASES FOR OPERA
TION
:
ANY
ONE
:At least one
phase picked up
;
ANY
TWO
:T
wo or more
phases picked up
;
ALL
THREE
:All three
phases picked up
;
AVERAGE
:A
verage value
picked up
.
Phase Currents
Second Harmonic Ratios
Message Event Recorder Transient Recorder
Message Event Recorder Transient Recorder
Do Not Operate, Operate
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