Ground Overcurrent - GE Multilin 489 Instruction Manual

5.6.7

Ground Overcurrent

1 GROUND
OVERCURRENT
Note
5–38
Courtesy of NationalSwitchgear.com
PATH: SETPOINTS S5 CURRENT ELEM.
[ ] GROUND OVERCURRENT
ALARM: Off
ASSIGN ALARM
MESSAGE
RELAYS (2-5): ---5
GROUND O/C ALARM
MESSAGE
PICKUP: 0.20 x CT
GROUND O/C ALARM
MESSAGE
DELAY: 0 cycles
GROUND OVERCURRENT
MESSAGE
ALARM EVENTS: Off
GROUND OVERCURRENT
MESSAGE
TRIP: Off
ASSIGN TRIP
MESSAGE
RELAYS (1-4): 1---
GROUND O/C TRIP
MESSAGE
PICKUP: 0.20 x CT
CURVE SHAPE:
MESSAGE
ANSI Extremely Inv.
FLEXCURVE TRIP TIME
MESSAGE
AT 1.03 x PU: 65535 ms
FLEXCURVE TRIP TIME
MESSAGE
AT 1.05 x PU: 65535 ms
↓
FLEXCURVE TRIP TIME
MESSAGE
AT 20.0 x PU: 65535 ms
OVERCURRENT CURVE
MESSAGE
MULTIPLIER: 1.00
OVERCURRENT CURVE
MESSAGE
RESET: Instantaneous
The 489 ground overcurrent feature consists of both an alarm and a trip element. The
magnitude of measured ground current 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.
CHAPTER 5: SETPOINTS
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 5–1: 489 Overcurrent
Curve Types on page –29.
Range: 0 to 65535 ms. Seen only if
CURVE SHAPE
Range: 0 to 65535 ms. Seen only if
CURVE SHAPE
Range: 0 to 65535 ms. Seen only if
CURVE SHAPE
Range: 0.00 to 1000.00 in steps of 0.01
Range: Instantaneous, Linear
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
is Flexcurve
is Flexcurve
is Flexcurve