GE Multilin 850, Instruction Manual

Page: 444 / 664

7–24 850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
FUNCTIONS CHAPTER 7: MONITORING
Current Demand
The Current Demand for each phase is calculated individually, and the Demand for each
phase is monitored by comparison with a single Current Demand Pickup value. If the
Current Demand Pickup is equalled or exceeded by any phase, the relay can cause an
alarm or signal an output relay.
Path : Setpoints > Monitoring > Functions > Demand > Current Demand 1(X)
FUNCTION
Range: Disabled, Alarm, Latched Alarm, Configurable
Default: Disabled
SIGNAL INPUT
Range: dependant upon the order code
Default: CT Bank 1-J1
This setting provides the selection for the current input bank. The bank names can be
changed in: Setpoints > System > Current Sensing > [Name] > CT Bank Name.
MEASUREMENT TYPE
Range: Blk Interval, Exponential, Rolling Dmd
Default: Blk Interval
This 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
This setpoint sets the time required for a steady state current to indicate 90% of the
actual value 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
This setpoint sets the time period over which the current demand calculation is to be
performed. The setpoint is visible only if MEASUREMENT TYPE is “Block Interval” or
“Rolling Demand”.
PICKUP
Range: 10 to 10000 A in steps of 1 A
Default: 1000 A
This setpoint sets the Current Demand Pickup level.
BLOCK
Range: Off, Any FlexLogic operand
Default: Off
OUTPUT RELAY X
For details see Common Setpoints .
EVENTS
Range: Enabled, Disabled
Default: Enabled
TARGETS
Range: Disabled, Self-reset, Latched
Default: Self-reset