
CHAPTER 6: SETPOINTS
S3 PROTECTION
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–111
Figure 6-49: Volts-per-hertz curves, inverse curve A
Inverse Curve B:
The curve for the Volts/Hertz Inverse Curve B shape is derived from the formula:
where:
T = Operating Time
TDM = Time Delay Multiplier (delay in seconds)
V = fundamental RMS value of voltage
F = frequency of voltage signal
Pickup = volts-per-hertz pickup setpoint