Low Forward Power - GE 489 Instruction Manual

4.8 S7 POWER ELEMENTS
T

LOW FORWARD POWER

T
[ENTER] for more
4
If enabled, once the magnitude of 3-phase total power in the forward direction (+MW) falls below the Pickup Level for a
period of time specified by the Delay, an alarm will occur. The level is programmed in per unit of generator rated MW calcu-
lated from the rated MVA and rated power factor. The low forward power element is active only when the generator is online
and will be blocked until the generator is brought online, for a period of time defined by the setpoint Block Low Fwd Power
From Online. The pickup level should be set lower than expected generator loading during normal operations. If the VT
type is selected as "None" or VT fuse loss is detected, the low forward power protection is disabled.
4-44
ð
BLOCK LOW FWD POWER
ENTER
FROM ONLINE: 0 s
ESCAPE
LOW FORWARD POWER
ESCAPE
ALARM: Off
MESSAGE
ASSIGN ALARM
ESCAPE
RELAYS (2-5): ---5
MESSAGE
LOW FWD POWER ALARM
ESCAPE
LEVEL: 0.05 x Rated MW
MESSAGE
LOW FWD POWER ALARM
ESCAPE
DELAY: 10.0 s
MESSAGE
LOW FWD POWER ALARM
ESCAPE
EVENTS: Off
MESSAGE
LOW FORWARD POWER
ESCAPE
TRIP: Off
MESSAGE
ASSIGN TRIP
ESCAPE
RELAYS (1-4): 1---
MESSAGE
LOW FWD POWER TRIP
ESCAPE
LEVEL: 0.05 x Rated MW
MESSAGE
LOW FWD POWER TRIP
ESCAPE
DELAY: 20.0 s
MESSAGE
489 Generator Management Relay
4 SETPOINT PROGRAMMING
4.8.4 LOW FORWARD POWER
Range: 0 to 15000 s in steps of 1
Range: Off, Latched, Unlatched
Range: Any combination of Relays 2 to 5
Range: 0.02 to 0.99 × Rated MW in steps of 0.01
Range: 0.2 to 120.0 s in steps of 0.1
Range: On, Off
Range: Off, Latched, Unlatched
Range: Any combination of Relays 1 to 4
Range: 0.02 to 0.99 × Rated MW in steps of 0.01
Range: 0.2 to 120.0 s in steps of 0.1
GE Power Management