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PROTECTION
Reactive Power
4–246
In a synchronous motor application, the reactive power element can be used to detect
excitation system malfunction, e.g. under excitation, loss of excitation, etc. Once the 3-
phase total reactive power exceeds the positive or negative level, for the specified delay, a
trip or alarm occurs indicating a positive or negative kvar condition. VTFF detection can be
used to block this function.
Path:
Setpoints > Protection > Group 1 > Power > Reactive Power
TRIP FUNCTION
Range: Disabled, Trip, Configurable
Default: Disabled
This setting enables the Reactive Power Trip functionality.
POSITIVE VAR TRIP PICKUP
Range: 1 to 25000 kvar in steps of 1
Default: 25 kvar
This setting specifies a pickup threshold for the positive var trip function.
NEGATIVE VAR TRIP PICKUP
Range: 1 to 25000 kvar in steps 1
Default: 25 kvar
This setting specifies a pickup threshold for the negative var trip function.
POSITIVE VAR TRIP DELAY
Range: 0.00 to 600.00 s in steps of 0.01 s
Default: 10.00 s
This setting specifies a time delay for the positive var trip function. Once the 3-phase
total reactive power exceeds the positive level for the duration of the Positive var Trip
Delay time, a trip will occur indicating a positive var condition.
NEGATIVE VAR TRIP DELAY
Range: 0.00 to 600.00 s in steps of 0.01 s
Default: 1.00 s
This setting specifies a time delay for the negative var trip function.
TRIP RELAYS
Range: Do Not Operate, Operate
Default: Do Not Operate
ALARM FUNCTION
Range: Disabled, Alarm, Latched Alarm
Default: Disabled
This setting enables the Reactive Power alarm functionality.
POSITIVE VAR ALARM PICKUP
Range: 1 to 25000 kvar in steps of 1
Default: 10 kvar
This setting is typically set at a level less than the Positive var Trip Pickup for the alarm
function.
NEGATIVE VAR ALARM PICKUP
Range: 1 to 25000 kvar in steps of 1
Default: 10 kvar
This setting specifies a pickup threshold for the negative var alarm function.
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS
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