3 phase 1.5kw water pump simple on/off

Hi All

I have a 3 phase waterpump that I would like to switch on and off remotely(gsm or wifi, will still decide which will suit me best)

My waterpump is 100% correctly installed with a phangle (load protection), with a magnetic contactor that is switched on and off by a simple "trip switch".

1.5kw motor, 380Vac.

My question... what is the best way to connect and use my arduino to remotely operate the "trip" switch?

Relays off course, or maybe some mechanical "hack" to just operate the physical switch?

All inputs and suggestions are greatly appreciated.



Please describe the nature of the trip switch. Picture maybe would help.


Here is a pic of the setup.

Why would you want to use an arduino when all you require is a slave relay driven by some form of receiver, such as a radio operated garage door controller.

You really need to offer a wiring diagram so's you can get a definitive answer, and which particular component(s) do you refer to when you state "trip switch" and "physical switch"

Did you get the name of the horse rider that wired up that panel :o

Haha, no idea who installed it, just bought the property.

I'll take some time tomorrow to get some more info.

Whoever wired the system is not someone I would employ as an electrician.

No concern what colours are used for phases or earths. What appears to be an earth lug, has blue, red and bare wires.

My advice is to get it done properly by a real electrician. He may be able to simplify the circuit and show you where to connect a relay to operate the system. Then you only need to look at what operates the relay.

Push button remotes are easily available from places like DX for less than $10.

Remember, mains voltage (especially 3phase) kills so if you don't know what you are doing, get an electrician.


The datasheet for that "PROTECHTOR" is enlightening. It shows that you can add a switch (a relay) in parallel to the water level sensors to turn the pump on or off.

It's important that you don't add any interface that doesn't work through the "PROTECHTOR". If you do you're going to lose the "protechtion" that prevents you from burning out your pump.