I have single phase submersible pump, around 400 foot underground in a Bore-well and its controlled by the controller shown below.

Pump controller

The green button is a push-button switch which if pushed and held for 5 seconds, starts the pump.

I would like to know what the switch is called, it has 4 contacts shown below (top right).

Inside of controller

Here is the complete album of the controller:


I am planning to replicate the switch function using Arduino and high load relay.

The button reads MAX 600V.


Does the button light up to indicate that the pump is running? If so, one pair of leads will be for the lamp, while the other pair are an SPST switch.

  • \$\begingroup\$ No, the button does not light up. \$\endgroup\$ – AMB Apr 15 '14 at 1:39
  • 1
    \$\begingroup\$ After a closer look at the switch, it appears to me that it actually has six terminals. The two (unused) screws flush with the back of the switch would be for a light, if it was lit, while the other four terminals in the corners are probably two single-pole, single-throw contacts (making the switch a DPST). You could confirm the contact arrangement by removing power, then disconnecting the leads (making note of where they go), then measuring resistance between contacts with the button pressed and released. \$\endgroup\$ – Peter Bennett Apr 15 '14 at 2:19

It's hard to tell exactly, but I'd guess with 4 connections, it is a DPST (double pole, single throw) switch. That is to say, two separate switches operated with a single button.

My advise is to, with power off, disconnect the four wires (marking them so you can properly reconnect) and then use an ohmmeter to confirm the operation of the button.

  • \$\begingroup\$ A close look at the button should reveal some sort of part number or connection diagram. My guess is it's controlled by the logic board seen in the picture. \$\endgroup\$ – John U Apr 14 '14 at 18:44
  • \$\begingroup\$ thats what i thought too, @John U : the logic board is used to trip/stop pump in case of dry-run/high load. \$\endgroup\$ – AMB Apr 15 '14 at 1:41
  • \$\begingroup\$ the logic behind is that, when i push button the the circuit starts the pump and while i hold that button for 5 seconds (which i am required to do so) additional current/voltage is provided to jump start the pump/motor as there are 3-4 capacitors in the controller box, \$\endgroup\$ – AMB Apr 15 '14 at 1:44

It appears to be a momentary push button. Most likely a dual pole. One pair of leads are normally closed, and the other pair are normally open. You can disconnect from the unit, set multimeter to continuity, then test each pair.


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