Price: £127.00
In Stock
Product Code: PHD

Available Options


The frequency protector trip relay provides a continuous surveillance of the monitored circuits and offers user adjustable trip points (set points) with time delay and differential (hysteresis) settings. When the frequency moves outside the set point limits for longer than the time delay, the relay will operate giving an alarm control or tripping signal. Since speed is proportional to frequency, this protector can be used to monitor under and over speed to protect mains, computers supplies and standby supplies.

Basic Parameters

  • Adjustable rated frequency, 50, 60 or 400Hz
  • Trip level adjustment between 80-120% (Fn) Under
  • Trip level adjustment between 80-120% (Fn) Over
  • Adjustable differential (hysteresis) 0.5-5%
  • Adjustable time delay 0.5-10s (t)

Click the PDF below to read more about the Crompton Instruments Single Phase Frequency PHD Protector Trip Relay.