GE Multilin 489 User Manual

5–48 489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
The formula for Volts/Hertz Curve 3 is:
(EQ 5.22)
where: T = trip time in seconds
D = VOLTS/HERTZ TRIP DELAY setpoint
V = RMS measurement of Vab
F = frequency of Vab
V
NOM
= generator voltage setpoint
F
S
= generator frequency setpoint
Pickup =
VOLTS/HERTZ TRIP PICKUP setpoint
The V/Hz Curve 3 trip curves are shown below for delay settings of 0.1, 0.3, 1, 3, and 10
seconds.
Note
Volts/Hertz is calculated per unit as follows:
5.7.4 Phase Reversal
PATH: SETPOINTS ZV S6 VOLTAGE ELEM. ZV PHASE REVERSAL
The 489 can detect the phase rotation of the three phase voltages. A trip will occur within
200 ms if the Phase Reversal feature is turned on, the generator is offline, each of the
phase-phase voltages is greater than 50% of the generator rated phase-phase voltage
T
D
VF⁄
V
nom
F
s
⁄()Pickup×
--------------------------------------------------
⎝⎠
⎛⎞
0.5
1–
-----------------------------------------------------------------------= , when
V
F
---
Pickup>
808743A1-X3.CDR
0.1
1
10
100
1000
10000
1.00 1.20 1.40 1.60 1.80 2.00
Multiples of Voltz/Hertz Pickup
10
3
1
0.3
TIME DELAY SETTING
0.1
Time to Trip (seconds)
Volts/Hertz
phase-phase voltage rated phase-phase voltage⁄
frequency rated frequency⁄
-----------------------------------------------------------------------------------------------------------------------------=
1 PHASE [Z]
REVERSAL
PHASE REVERSAL
TRIP: Off
Range: Off, Latched, Unlatched
MESSAGE
ASSIGN TRIP
RELAYS (1-4): 1---
Range: Any combination of Relays 1 to
4
Courtesy of NationalSwitchgear.com

GE Multilin 489 Specifications

General

Brand	GE
Model	Multilin 489
Category	Relays
Language	English