Pump Protection Relay – Three phase by COS φ – PF-R

Pump Protection Relay – Three phase by COS φ – PF-R

Using the motor itself as a sensor and without requiring any external detectors, they monitor the cos φ of the motor and stop it before a breakdown occurs caused by dry running, cavitation or closed valve.

Some of the most common applications in domestic, industrial and agricultural installations are as follow:

Submersible pumps: water supply, irrigation, well dewatering, petrol stations…
Surface pumps: sewage treatment plants, swimming pools, pressure sets, fire-fighting equipment…
Other typical applications that require monitoring: belt drives, ventilators, conveyor belts…

  • Without requiring level sensors to detected dry running.
  • For three phase motors from 1 to 630 A and over. Cable feed through.
  • Precise motor heating and cooling memory, reproduces its thermal image.
  • Visual indication of tripping cause.
  • Adjustable reset time for cos φ.


Protection functions:

  • Overload
  • Underload cos φ
  • Phase imbalance or phase loss
  • Phase sequence