GE Multilin 565 Instruction Manual page 86

SETPOINTS MODE - VOLTAGE
Location Message Line
S 9.6
UNDERVOLT TRIP
DISABLED
Messages S 9.7 to S 9.9 will only appear if ENABLED is selected in message S 9.6.
S 9.7
UNDERVOLT TRIP
LEVEL
S 9.8
UNDERVOLT TRIP
DELAY
S 9.9
UNDERVOLT TRIP
RELAY TRIP&AUX1
S 9.10
UNDERVOLT ALARM
L DISABLED
A
Messages S 9.11 to 9.13 will only appear if ENABLED is selected in message S 9.10.
S 9.11
UNDERVOLT ALARM
LEVEL
L
A
S 9.12
UNDERVOLT ALARM
L
DELAY
A
S 9.13
UNDERVOLT ALARM
L
RELAY
A
S 9.14
OVERVOLT TRIP
L
A
5-42
Description
only occur when the breaker is detected as closed.
This message allows the undervoltage trip to be enabled or disabled. The
Undervoltage Trip feature will activate when any two line-to-line voltages
stay below the trip setpoint for the selected time delay. NOTE: When an
undervoltage condition is present the reclosure scheme will not issue a
close command to the breaker. When the undervoltage condition is no
longer present, the breaker should be closed manually.
The undervoltage trip level is entered here as a percentage of the VT
rating. Feeder undervoltage protection is necessary because a significant
80 %VT
drop in feeder voltage indicates a system fault.
The 565/575 Relay monitors the phase voltages while the breaker is
closed and provides a trip signal if the level drops to the value which you
enter here. The range of possible settings for the undervoltage setpoint is
50% to 100% of the VT rating in steps of 1%. Refer to Table 2.1 to
determine how many phases must be below the trip level to cause a trip for
the VT connection being used.
The delay on the undervoltage trip is entered here, in the range of 0.1 to
25.5 seconds in steps of 0.1 seconds. This prevents nuisance trips caused
1.0 SEC
by momentary low voltages due to sudden switching of heavy loads on or
off the feeder. Should the condition persist beyond the timed period the trip
will occur.
This message allows the user to select the relay which the trip signal
generated in message S 9.6 will activate.
This message allows the undervoltage alarm to be enabled or disabled.
The undervoltage alarm level is entered here as a percentage of the VT
rating. Feeder undervoltage alarms are necessary to warn of impending
85 %VT
voltage related problems. The range of possible settings for the undervolt-
age alarm setpoint is 50% to 100% of the VT rating in steps of 1%. Refer
to Table 2.1 to determine how many phases must be below the alarm level
to cause an alarm for the VT connection being used.
The delay on the undervoltage alarm is entered here, in the range of 0.1 to
25.5 seconds in steps of 0.1 seconds. See message S 9.8 for more
1.0 SEC
information.
This message allows the user to select the relay which the alarm signal
generated in message S 9.10 will activate.
AUX2
This message allows the overvoltage trip to be enabled or disabled. The
overvoltage trip feature will activate when any phase voltage stays above
DISABLED
the trip setpoint for the selected time delay. NOTE: When an overvoltage
condition is present the reclosure scheme will not issue a close command
to the breaker. When the overvoltage condition is no longer present, the
breaker should be closed manually.