GE Multilin 489

CHAPTER 5: SETPOINTS
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL 5–47
The V/Hz Curve 1 trip curves are shown below for delay settings of 0.1, 0.3, 1, 3, and 10
seconds.
The formula for Volts/Hertz Curve 2 is:
(EQ 5.21)
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 2 trip curves are shown below for delay settings of 0.1, 0.3, 1, 3, and 10
seconds.
808743A1-X1.CDR
0.01
0.1
1
10
100
1000
1.00 1.20 1.40 1.60 1.80 2.00
Multiples of Volts/Hertz Pickup
10
3
1
0.3
TIME DELAY SETTING
Time to Trip (seconds)
0.1
T
D
VF⁄
V
nom
F
s
⁄()Pickup×
--------------------------------------------------
1–
-----------------------------------------------------------= , when
V
F
---
Pickup>
808743A1-X2.CDR
0.1
1
10
100
1000
1.00 1.20 1.40 1.60 1.80 2.00
Multiples of Volts/Hertz Pickup
10
3
1
0.3
TIME DELAY SETTING
0.1
Time to Trip (seconds)
Courtesy of NationalSwitchgear.com