Inadvertent Energization - GE 489 Instruction Manual

4 SETPOINT PROGRAMMING
T
INADVERTENT ENERG.
T
[ENTER] for more
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.
NOTE
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.
I > O/C Level
phase
V < U/V Level
phase
Breaker Status =Off-Line
Arming Signal = U/V or Offline
GE Power Management
ð
INADVERTENT ENERGIZE
ENTER
TRIP: Off
ESCAPE
ASSIGN ALARM
ESCAPE
RELAYS (1-4): 1---
MESSAGE
ARMING SIGNAL:
ESCAPE
U/V and Offline
MESSAGE
INADVERTENT ENERGIZE
ESCAPE
O/C PICKUP: 0.05 x CT
MESSAGE
INADVERTENT ENERGIZE
ESCAPE
PICKUP: 0.50 x Rated V
MESSAGE
AND AND
OR OR
AND AND
Figure 4–1: INADVERTENT ENERGIZATION
489 Generator Management Relay
4.6 S5 CURRENT ELEMENTS

4.6.4 INADVERTENT ENERGIZATION

Range: Off, Latched, Unlatched
Range: Any combination of Relays 1 to 4
Range: U/V and Offline, U/V or Offline
Range: 0.05 to 3.00 × CT in steps of 0.01
Range: 0.50 to 0.99 × Rated Voltage in steps of 0.01
AND AND
5 s
OR OR
250 ms
4
Operate
4-21