Ground Overcurrent - GE 489 Instruction Manual

4 SETPOINTS
PATH: SETPOINTS S5 CURRENT ELEMENTS
GROUND O/C
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The 489 ground overcurrent feature consists of both an alarm and a trip element. The magnitude of measured ground cur-
rent is used to time out against the definite time alarm or inverse time curve trip. The 489 inverse time curve for this element
may be either ANSI, IEC, or GE Type IAC standard curve shapes. This allows for simplified coordination with downstream
devices. If however, none of these curves shapes is adequate, the FlexCurve™ may be used to customize the inverse time
curve characteristics. If the Ground CT is selected as "None", the ground overcurrent protection is disabled.
The pickup level for the ground current elements is programmable as a multiple of the CT. The 50:0.025 CT
is intended for very sensitive detection of ground faults and its nominal CT rating for the 489 is 50:0.025.
NOTE
For example, if the ground CT is 50:0.025, a pickup of 0.20 would be 0.20 × 5 = 1 A primary. If the ground CT is 50:0.025, a
pickup of 0.05 would be 0.05 × 5 = 0.25 A primary.
GE Multilin
GROUND O/C
ð

GROUND OVERCURRENT

ENTER
ð
ESCAPE ALARM: Off
ASSIGN ALARM
ESCAPE
RELAYS (2-5): ---5
MESSAGE
GROUND O/C ALARM
ESCAPE
PICKUP: 0.20 x CT
MESSAGE
GROUND O/C ALARM
ESCAPE
DELAY: 0 cycles
MESSAGE
GROUND OVERCURRENT
ESCAPE
ALARM EVENTS: Off
MESSAGE
GROUND OVERCURRENT
ESCAPE
TRIP: Off
MESSAGE
ASSIGN TRIP
ESCAPE
RELAYS (1-4): 1---
MESSAGE
GROUND O/C TRIP
ESCAPE
PICKUP: 0.20 x CT
MESSAGE
CURVE SHAPE:
ESCAPE
ANSI Extremely Inv.
MESSAGE
FLEXCURVE TRIP TIME
ESCAPE
AT 1.03 x PU: 65535 ms
MESSAGE
FLEXCURVE TRIP TIME
ESCAPE
AT 1.05 x PU: 65535 ms
MESSAGE
↓
FLEXCURVE TRIP TIME
ESCAPE
AT 20.0 x PU: 65535 ms
MESSAGE
OVERCURRENT CURVE
ESCAPE
MULTIPLIER: 1.00
MESSAGE
OVERCURRENT CURVE
ESCAPE
RESET: Instantaneous
MESSAGE
489 Generator Management Relay
4.6 S5 CURRENT ELEMENTS
4.6.7 GROUND OVERCURRENT
Range: Off, Latched, Unlatched
Range: Any combination of Relays 2 to 5
Range: 0.05 to 20.00 × CT in steps of 0.01
Range: 0 to 100 cycles in steps of 1
Range: On, Off
Range: Off, Latched, Unlatched
Range: Any combination of Relays 1 to 4
Range: 0.05 to 20.00 × CT in steps of 0.01
Range: see Table 4–1: 489 Overcurrent Curve Types on
page 4–21.
Range: 0 to 65535 ms
Seen only if CURVE SHAPE is Flexcurve
Range: 0 to 65535 ms
Seen only if CURVE SHAPE is Flexcurve
Range: 0 to 65535 ms
Seen only if CURVE SHAPE is set to Flexcurve
Range: 0.00 to 1000.00 in steps of 0.01
Range: Instantaneous, Linear
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