CHAPTER 6: SETPOINTS
S3 PROTECTION
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–93
Figure 29: Phase undervoltage logic diagram
Phase
V
oltage
Inputs
(associated
setpoints)
SETPOINTS
Va
b
SETPOINT
PH
UV
FUNCTION:
Disabled
=
0
Latched
Alarm
PH
UV
PICKUP:
PH
UV
CUR
VE:
PH
UV
DELA
Y:
AND
Vbc
Vca
Operate
Output
Relay
1
(TRIP)
Event
Recorder
LED:
TRIP
Alarm
OR
OR
AND
SETPOINTS
Operate
output
relays
upon
selection
OUTPUT
RELA
Y
4
OUTPUT
RELA
Y
5
OUTPUT
RELA
Y
6
OUTPUT
RELA
Y
3
T
rip
AND
T
rip
(T
o
B
reaker
Failure)
SETPOINTS
BLOCK
1:
O
ff=0
BLOCK
2:
O
ff=0
BLOCK
3:
O
ff=0
OR
RUN
RUN
RUN
PICKUP
Va
n
Vbn
Vcn
None
PICKUP
PICKUP
V
a
n
o
r
V
ab
>
Minimum
Vbn
or
Vbc
>
Minimum
Vcn
or
Vca
>
Minimum
PH
UV
MIN
VOL
T
AGE:
SETPOINT
AND
AND
AND
Delta
Wy
e
All
Three
Any
One
Any
T
w
o
Operate
for
programmed
combination
Any
T
w
o
Any
One
All
Three
Pickup
for
Programmed
Combination
SETPOINT
PH
UV
PHASES:
OR
OR
LED:
PICKUP
Phase
Undervoltage
Message
LED:
ALARM
RESET
Command
AND
S
R
LA
TCH
898014A1.cdr
