Inverse Volts-Per-Hertz Curves; Inverse Curve 1 - GE 745 TRANSFORMER MANAGEMENT RELAY Instruction Manual

5 SETPOINTS

5.10 INVERSE VOLTS-PER-HERTZ CURVES

The curve for the inverse curve 1 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)
1000
100
10
1
0.1
0.01
1.00
GE Power Management
D
T = when
---------------------------------- -
V F ⁄
2
 
----------------- - – 1
 
Pickup
1.20 1.40
Multiples of Volts/Hertz Pickup
Figure 5–16: INVERSE CURVE 1
745 Transformer Management Relay
5.10 INVERSE VOLTS-PER-HERTZ CURVES

5.10.1 INVERSE CURVE 1

V
>
--- - Pickup
F
1.60 1.80
Time
Delay
5
Setting
ò
10
3
1
0.3
0.1
2.00
5-97