Operation Manual 37107F
MFR 3 - Multi Function Relay
Page 110/165
© Woodward
Generator Undervoltage Monitoring
The line-to-line voltage is monitored to detect undervoltage conditions.
Function: "
Generator voltage not within the permissible range"
At least one phase of the generator voltage is outside of the limit values configured for undervoltage. The enabl-
ing of generator undervoltage monitoring is delayed via "Delayed monitoring" in order to enable correct genera-
tor start-up. An alarm is issued if a fault condition is detected.
NOTE
Energizing terminal 6 ("monitoring") enables this monitoring.
Parameter
168
Gen.undervolt.
monitoring ON
Generator undervoltage
ON/OFF
ON
................ Generator undervoltage monitoring is enabled. The subsequent
screens of this function are displayed.
OFF
.............. Generator undervoltage monitoring is not performed. The subsequent
screens of this function are not displayed.
Parameter
169
Gen.undervolt. 1
U > 000V
Generator undervoltage: limit 1
[1] 20 to 150 V; [4] 20 to 520 V
The value for undervoltage limit 1 is configured in this screen. If the monitored
voltage reaches or falls below this level for the configured delay time, the unit is-
sues an alarm and opens the GCB. This value refers to the secondary voltage of the
generator PT inputs (Parameter 15).
Tripping of class F3 alarm
Parameter
170
Gen.undervolt. 1
Delay 00.00s
Generator undervoltage: delay 1
0.02 to 99.98 s
The generator undervoltage monitoring threshold limit 1 must be exceeded, without
interruption, for the time period configured here before the configured relay will be
energized.
Parameter
171
Gen.undervolt. 2
U > 000V
Generator undervoltage: limit 2
[1] 20 to 150 V; [4] 20 to 520 V
The value for undervoltage limit 2 is configured in this screen. If the monitored
voltage reaches or falls below this level for the configured delay time, the unit is-
sues an alarm and opens the GCB. This value refers to the secondary voltage of the
generator PT inputs (Parameter 15).
Tripping of class F3 alarm
Parameter
172
Gen.undervolt. 2
Delay 00.00s
Generator undervoltage: delay 2
0.02 to 99.98 s
The generator undervoltage monitoring threshold limit 1 must be exceeded, without
interruption, for the time period configured here before the configured relay will be
energized.