6–50
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
S3 PROTECTION
CHAPTER 6: SETPOINTS
Figure 6-21: Ground/Sensitive Ground timed overcurrent protection: Logic Diagram
SETPOINTS
RUN
SETPOINT
GND
TOC FUNCTION:
Disabled = 0
Alarm
GND
TOC PICKUP:
GND
TOC CUR
VE:
GND
TO
C
TD MUL
TIPLIER:
Ig > PICKUP
AND
Operate Output Relay 1 (TRIP)
Event Recorder
Transient Recorder
LED: PICKUP
GND
TOC PKP
LED:
TRIP
Event Recorder
Transient Recorder
Latched
Alarm
OR
OR
Message:
GND
TOC OP
Adjust PKP
Adjust Gnd/S.Gnd T
OC PKP
AND
SETPOINTS:
Do Not Operate, Operate
OUTPUT
RELA
Y X
Trip
AND
Trip (T
o Breaker Failure)
GND
TOC RESET
:
Ground/Sens. Ground current (Ig)
From Ground CT or
,
From Sens. Ground CT
SETPOINTS
BLOCK 1:
Of
f = 0
BLOCK 2:
Of
f = 0
BLOCK 3:
Of
f = 0
OR
Autoreclose
(per shot settings)
Cold Load PKP
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
898006A2.cdr
GND
T
OC DIRECTION
:
Forward
Disabled
Reverse
AND
AND
GND DIR Reverse
From GROUND DIRECTIONAL
GND DIR Forward
OR
BLK GND DIR OC UND
AND
SETPOINT