S6 Voltage Elements; Undervoltage - GE 489 Instruction Manual
Generator management relay
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Also See for 489:
- Instruction manual (314 pages) ,
- Communications manual (78 pages) ,
- Instruction manual (38 pages)
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4 SETPOINTS
4.7S6 VOLTAGE ELEMENTS
PATH: SETPOINTS
S6 VOLTAGE ELEMENTS
UNDERVOLTAGE
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The undervoltage elements may be used for protection of the generator and/or its auxiliary equipment during prolonged
undervoltage conditions. They are active only when the generator is online. The alarm element is definite time and the trip
element can be definite time or a curve. When the magnitude of the average phase-phase voltage is less than the pickup ×
the generator rated phase-phase voltage, the element will begin to time out. If the time expires, a trip or alarm will occur.
The curve reset rate is a linear reset time from the threshold
of trip. If the VT type is selected as None, VT fuse loss is
detected, or the magnitude of I
protection is disabled. The pickup levels are insensitive to
frequency over the range of 5 to 90 Hz.
The formula for the undervoltage curve is:
D
T
----------------------------------- -
,
when V V
=
⁄
1 V V
–
pickup
where: T = trip time in seconds
D =
UNDERVOLTAGE TRIP DELAY
V = actual average phase-phase voltage
V
=
UNDERVOLTAGE TRIP PICKUP
pickup
GE Multilin
UNDERVOLTAGE
ð
UNDERVOLTAGE
ENTER
ð
ESCAPE
ALARM: Off
ASSIGN ALARM
ESCAPE
RELAYS (2-5): ---5
MESSAGE
UNDERVOLTAGE ALARM
ESCAPE
PICKUP: 0.85 x Rated
MESSAGE
UNDERVOLTAGE ALARM
ESCAPE
DELAY: 3.0 s
MESSAGE
UNDERVOLTAGE ALARM
ESCAPE
EVENTS: Off
MESSAGE
UNDERVOLTAGE
ESCAPE
TRIP: Off
MESSAGE
ASSIGN TRIP
ESCAPE
RELAYS (1-4): 1---
MESSAGE
UNDERVOLTAGE TRIP
ESCAPE
PICKUP: 0.80 x Rated
MESSAGE
UNDERVOLTAGE TRIP
ESCAPE
DELAY: 1.0 s
MESSAGE
UNDERVOLTAGE CURVE
ESCAPE
RESET RATE: 1.4 s
MESSAGE
UNDERVOLTAGE CURVE
ESCAPE
ELEMENT: Curve
MESSAGE
< 7.5% CT, the undervoltage
1
<
(EQ 4.18)
pickup
setpoint
setpoint
489 Generator Management Relay
4.7 S6 VOLTAGE ELEMENTS
4.7.1 UNDERVOLTAGE
Range: Off, Latched, Unlatched
Range: Any combination of Relays 2 to 5
Range: 0.50 to 0.99 × Rated 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: 0.50 to 0.99 × Rated in steps of 0.01
Range: 0.2 to 10.0 s in steps of 0.1
Range: 0.0 to 999.9 s in steps of 0.1
Range: Curve, Definite Time
1000
100
10
1
0.1
0
0.2
0.4
0.6
Multiples of Undervoltage Pickup
4
10
3
1
0.3
0.8
1
808742A1.CDR
4-33
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