GE 889 Instruction Manual page 438

MONITORING
Apparent Power Demand
4–308
The Apparent Power Demand is monitored by comparing to a Pickup value. If the Apparent
Power Demand Pickup is ever equalled or exceeded, the relay can be configured to cause
an alarm or signal an output relay.
Path: Setpoints > Monitoring > Functions > Demand > Apparent Power Demand 1(X)
FUNCTION
Range: Disabled, Alarm, Latched Alarm, Configurable
Default: Disabled
MEASUREMENT TYPE
Range: Blk Interval, Exponential, Rolling Dmd
Default: Blk Interval
The setting sets the measurement method. Three methods can be applied.
THERMAL 90% RESPONSE TIME
Range: 5 min, 10 min, 15 min, 20 min, 30 min
Default: 15 min
The setpoint sets the time required for a steady state Apparent Power to indicate 90% of
the actual value and allows the user to approximately match the response of the relay
to analog instruments. The setpoint is visible only if MEASUREMENT TYPE is "Thermal
Exponential".
TIME INTERVAL
Range: 5 min, 10 min, 15 min, 20 min, 30 min
Default: 20 min
The setpoint sets the time period over which the Apparent Power Demand calculation is
to be performed. The setpoint is visible only if MEASUREMENT TYPE is "Block Interval" or
"Rolling Demand".
PICKUP
Range: 0.1 to 300000.0 kVA in steps of 0.1 kVA
Default: 1000.0 kVA
The setting sets the Apparent Power Demand Pickup level.
BLOCK
Range: Off, Any FlexLogic operand
Default: Off
OUTPUT RELAY X
For details see Common
EVENTS
Range: Enabled, Disabled
Default: Enabled
TARGETS
Range: Disabled, Self-reset, Latched
Default: Self-reset
Setpoints.
889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 4: SETPOINTS