Power Monitor and Alarm protects your pumps and processes.

three phase power alarm and monitor
The best power failure alarm
  • Always on duty – ultra-low power consumption allows Lithium battery to last for 10 years or more.


  • Very loud alarm. 103dB! warbling pattern cuts through ambient noise.
  • Silence button with  30-minute “snooze alarm” setting.
  • Bright flashing beacon LED. Bright enough to be visible in daylight.
  • Displays current voltage of your selected phases. 
  • Relay output to protect a pump by shutting it down.


Three phase power monitor continuously monitors AC power and gives an alarm if any phase voltage falls outside the parameters you set.  In this case, the very LOUD buzzer sounds, and the beacon LED flashes.  The buzzer can be silenced with the front button.

Simple installation, just connect the three phases to the inputs marked.  Wire gage doesn’t matter. After that, just connect the provided 9V lithium battery and you are in business.



The front display indicates the status of one of the phases you select.  There is no need to do anything when the unit is monitoring.  If the voltage on any phase drops below or above the value you set, then an alarm is given and the exact problem is displayed on the panel.  When an alarm sounds, the front (blue) push button silences the buzzer for 30 minutes. The LED continues to flash until power is corrected. (in the default setup)


The voltage monitoring parameters that can be set are all accessed from the green button on the module. See video for a walk-through of all the setting.

  • Under voltage
  • Over voltage
  • Asymmetry (difference between phases)
  • Time delays before alarm

The other setup is the alarm behavior, either repeating buzzer, or one and done. (see instructions in the “Documents” tab below)

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PFA-3 three phase power alarm and monitor

$487.  Includes Lithium battery