GE Multilin 489 Instruction Manual page 156
Generator management relay
Hide thumbs
Also See for Multilin 489:
- Instruction manual (306 pages) ,
- Communications manual (78 pages) ,
- Instruction manual (259 pages)
Table of Contents
Advertisement
5–46
Courtesy of NationalSwitchgear.com
VOLTS/HERTZ ALARM
MESSAGE
PICKUP: 1.00 xNominal
VOLTS/HERTZ ALARM
MESSAGE
DELAY: 3.0 s
VOLTS/HERTZ ALARM
MESSAGE
EVENTS: Off
VOLTS/HERTZ
MESSAGE
TRIP: Off
ASSIGN TRIP
MESSAGE
RELAYS (1-4): 1---
VOLTS/HERTZ TRIP
MESSAGE
PICKUP: 1.00 xNominal
VOLTS/HERTZ TRIP
MESSAGE
DELAY: 1.0 s
VOLTS/HERTZ CURVE
MESSAGE
RESET RATE: 1.4 s
VOLTS/HERTZ TRIP
MESSAGE
ELEMENT: Curve #1
The Volts Per Hertz elements may be used generator and unit transformer protection. They
are active as soon as the magnitude and frequency of V
element is definite time; the trip element can be definite time or a curve. Once the V/Hz
measurement V
exceeds the pickup level for the specified time, a trip or alarm will occur.
ab
The reset rate is a linear reset time from the threshold of trip and should be set to match
cooling characteristics of the protected equipment. The measurement of V/Hz will be
accurate through a frequency range of 5 to 90 Hz. Settings less than 1.00 only apply for
special generators such as short circuit testing machines.
The formula for Volts/Hertz Curve 1 is:
T
------------------------------------------------------------------ -
=
V F ⁄
⎛
------------------------------------------------- -
⎝
(
V
⁄
F
nom
s
where: T = trip time in seconds
D =
VOLTS/HERTZ TRIP DELAY
V = RMS measurement of Vab
F = frequency of Vab
V
= generator voltage setpoint
NOM
F
= generator frequency setpoint
S
Pickup =
VOLTS/HERTZ TRIP PICKUP
Range: 0.50 to 1.99 ×Nominal in steps
Range: 0.1 to 150.0 s in steps of 0.1
Range: On, Off
Range: Off, Latched, Unlatched
Range: Any combination of Relays 1 to
Range: 0.50 to 1.99 ×Nominal in steps
Range: 0.1 to 150.0 s in steps of 0.1
Range: 0.0 to 999.9 s in steps of 0.1
Range: Curve #1, Curve #2, Curve #3,
is measurable. The alarm
ab
D
V
, when
-- -
>
Pickup
F
2
⎞
1
–
⎠
) Pickup
×
setpoint
setpoint
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
of 0.01
4
of 0.01
Definite Time
(EQ 5.20)
Advertisement
Table of Contents
