Generator; General; Percent Differential Current - GE 889 Instruction Manual

CHAPTER 6: METERING

Generator

General

Percent Differential Current

889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
Path:
Metering > Generator > General
LOAD CURRENT
Range: 0.0 to 40.0 x FLA in steps of 0.1 x FLA
Default: 0.0 x FLA
This value represents the ratio of the average of the three-phase RMS currents (from the
J-slot) with the generator rated FLA (rated full load current, calculated from the values
entered in Path: Setpoints > System > Generator
UNBALANCE CURRENT
Range: 0 to 100 % FLA in steps of 1 % FLA
Default: 0 % FLA
This value represents the calculated generator unbalance (negative sequence) current
(from the J-slot) as a percentage of the generator rated FLA (rated full load current,
calculated from the values entered in Path:
can be used to set the Generator Unbalance protection element.
EXCITATION CURRENT
Range: -50000 to 50000 units in steps of 1 unit
Default: 0 units
This value is available when an Analog Input is enabled with Function set to Excitation
Current. The displayed unit is the same as that set in the Analog Input Unit setpoint (in
this example it is set to "units").
BEARING VIRBRATION
Range: -50000 to 50000 units in steps of 1 unit
Default: 0 units
This value is available when an Analog Input is enabled with Function set to Bearing
Vibration. The displayed unit is the same as that set in the Analog Input Unit setpoint (in
this example it is set to "units").
The phasors of differential and restraint currents are displayed in primary amperes.
Path: Metering > Generator > Percent Differential
Phase A differential (Ia Diff)
Range: 0.000 to 120000.000 A
Phase B differential (Ib Diff)
Range: 0.000 to 120000.000 A
Phase C differential (Ic Diff)
Range: 0.000 to 120000.000 A
Phase A restraint (Ia Restr)
Range: 0.000 to 120000.000 A
Phase B restraint (Ib Restr)
Range: 0.000 to 120000.000 A
Phase C restraint (Ic Restr)
Range: 0.000 to 120000.000 A
).
Setpoints > System > Generator
GENERATOR
). This value
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