Overfrequency - GE Multilin 489 Instruction Manual

5.7.6

Overfrequency

1 OVERFREQUENCY
5–50
Courtesy of NationalSwitchgear.com
PATH: SETPOINTS S6 VOLTAGE ELEM.
[ ] BLOCK OVERFREQUENCY
FROM ONLINE: 1 s
VOLTAGE LEVEL
MESSAGE
CUTOFF: 0.50 x Rated
OVERFREQUENCY
MESSAGE
ALARM: Off
ASSIGN ALARM
MESSAGE
RELAYS (2-5): ---5
OVERFREQUENCY
MESSAGE
ALARM LEVEL: 60.50 Hz
OVERFREQUENCY
MESSAGE
ALARM DELAY: 5.0 s
OVERFREQUENCY
MESSAGE
ALARM EVENTS: Off
OVERFREQUENCY
MESSAGE
TRIP: Off
ASSIGN TRIP
MESSAGE
RELAYS (1-4): 1---
OVERFREQUENCY
MESSAGE
TRIP LEVEL1: 60.50 Hz
OVERFREQUENCY
MESSAGE
TRIP DELAY1: 60.0 s
OVERFREQUENCY
MESSAGE
TRIP LEVEL2: 62.00 Hz
OVERFREQUENCY
MESSAGE
TRIP DELAY2: 30.0 s
It may be undesirable to enable the overfrequency elements until the generator is online.
This feature can be blocked until the generator is online and the block time expires. From
that point forward, the overfrequency trip and alarm elements will be active. A value of
zero for the block time indicates that the overfrequency protection is active as soon as
voltage exceeds the cutoff level (programmed as a multiple of the generator rated phase-
phase voltage). Frequency is then measured. Once the frequency of Vab exceeds the
overfrequency setpoints, for the period of time specified, a trip or alarm will occur. There
are dual level and time setpoints for the trip element.
CHAPTER 5: SETPOINTS
OVERFREQUENCY
Range: 0 to 5 s in steps of 1
Range: 0.50 to 0.99 × Rated in steps of
0.01
Range: Off, Latched, Unlatched
Range: Any combination of Relays 2 to
5
Range: 25.01 to 70.00 Hz in steps of
0.01
Range: 0.1 to 5000.0 s in steps of 0.1
Range: On, Off
Range: Off, Latched, Unlatched
Range: Any combination of Relays 1 to
4
Range: 25.01 to 70.00 Hz in steps of
0.01
Range: 0.1 to 5000.0 s in steps of 0.1
Range: 25.01 to 70.00 Hz in steps of
0.01
Range: 0.1 to 5000.0 s in steps of 0.1
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL