GE 489 - Manual (Page 75)

GE Multilin 489 Generator Management Relay 4-25
4 SETPOINTS 4.6 S5 CURRENT ELEMENTS
4
4.6.4 INADVERTENT ENERGIZATION
PATH: SETPOINTS ÖØ S5 CURRENT ELEMENTS ÖØ INADVERTENT ENERG.
The logic diagram for the inadvertent energization protection feature is shown below. The feature may be armed when all of
the phase voltages fall below the undervoltage pickup level and the unit is offline. This would be the case when the VTs are
on the generator side of the disconnect device. If however, the VTs are on the power system side of the disconnect device,
the feature should be armed if all of the phase voltages fall below the undervoltage pickup level or the unit is offline. When
the feature is armed, if any one of the phase currents measured at the output CTs exceeds the overcurrent level pro-
grammed, a trip will occur.
5 seconds to arm, 250 ms to disarm.
Protection can be provided for poor synchronization by using the "U/V or Offline" arming signal. During normal synchroniza-
tion, there should be relatively low current measured. If however, synchronization is attempted when conditions are not
appropriate, a large current that is measured within 250 ms after the generator is placed online would result in a trip.
Figure 4–1: INADVERTENT ENERGIZATION
„ INADVERTENT ENERG.
„ [ENTER] for more
INADVERTENT ENERGIZE
TRIP: Off
Range: Off, Latched, Unlatched
ASSIGN ALARM
RELAYS (1-4): 1---
Range: Any combination of Relays 1 to 4
ARMING SIGNAL:
U/V and Offline
Range: U/V and Offline, U/V or Offline
INADVERTENT ENERGIZE
O/C PICKUP: 0.05 x CT
Range: 0.05 to 3.00 × CT in steps of 0.01
INADVERTENT ENERGIZE
PICKUP: 0.50 x Rated V
Range: 0.50 to 0.99 × Rated Voltage in steps of 0.01
ENTER
ESCAPE
р
р
MESSAGE
ESCAPE
MESSAGE
ESCAPE
MESSAGE
ESCAPE
MESSAGE
ESCAPE
NOTE
AND
AND
AND
OR OR
OR OR
V < U/V Level phase
I > O/C Level phase Operate
Breaker Status = Offline
Arming Signal = U/V or Offline
5 s
250 ms
808731A1.CDR