Inverse Curve 3 - GE 745 TRANSFORMER MANAGEMENT RELAY Instruction Manual

5 SETPOINTS
The curve for the inverse curve 3 shape is derived from the formula:
where T = operate time (seconds)
D = delay setpoint (seconds)
V = fundamental RMS value of voltage (V)
F = frequency of voltage signal (Hz)
Pickup = volts-per-hertz pickup setpoint (V/Hz)
10000
1000
100
10
1
0.1
1.00
GE Power Management
D
T = when
-------------------------------------- -
V F ⁄
0.5
 
----------------- - – 1
 
Pickup
1.20 1.40
Multiples of Voltz/Hertz Pickup
Figure 5–18: INVERSE CURVE 3
745 Transformer Management Relay
5.10 INVERSE VOLTS-PER-HERTZ CURVES

5.10.3 INVERSE CURVE 3

V
>
--- - Pickup
F
1.60 1.80
Time
5
Delay
Setting
ò
10
3
1
0.3
0.1
2.00
5-99