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Son off Pow R2 for 220V AC Unit only has 1 input for wiring

I bought a SonOff pow R2 to work with my 220V A/C Unit . My electrician says it cant work because our 220 V system uses 2 input wires but the sonoff only uses 1. he said something about it being a europpean system being different. What can he do to work around it?

The electrician, if he is worth his salt, can size and recommend a contactor/enclosure.  I have bought them on Amazon in the $10 to $30 range and mounted them in metal boxes  in the same neighborhood of price.  You are probably looking at $20 to $50 for the parts. 

By the way, if you intend to monitor the power consumption with the POW then the contactor method will not work.  The AC load current will be passing through the contactor.  The POW will only see the tiny amount of power needed to energize the coil.  You may as well just use a Basic.

Thank you EW. Will I be able to use all the other features of the sonoff? Like remote lock off and using the app to monitor hours of use etc Btw. Is this the only work around you can think of? I like the way your brain thinks. Can you dig any deeper for a more str8 forward solution.

Yes and no.  You can remotely lock it off but there will be no way to know if the unit is actually running since you can't see the power consumption.  All you will know for sure is whether the power to it is available for operation.  In other words you can see if the contactor is open or closed but not whether someone actually turned the unit on.


Unless we are talking about a large AC system or the rare window unit with an internal contactor that is about all I have to offer.   With a system that already contains a control circuit it might be possible to integrate a Sonoff or Sonoff SV inside the unit itself or the thermostat.

One other thought that just occurred to me is that if the unit you are controlling has an electronic control instead of the old mechanical switch and thermostat you might be "up the creek".  When you remove and apply power to those things they are initially in an "OFF" state and require button pushes to turn on.  Of course an electronic control might lend itself to a Sonoff simulating a button push if you are willing to hack into it a bit.

The AC has a remote and also a on/off button on the unit itself. When the son off is installed will I be able to use these turn the unit on or off. Or control will have to be through the son off only?

If it is electronic the Sonoff isn't going to turn it on.   When power is applied the initial state is off and requires a button push.

If it were me I would look at some of the wi-fi enabled AC remotes like the Switchbot.

Ew I like the sonoff idea but it will b 2 costly to do the adjustments compared to just buying a different device. Is there any version of the sonoff that works with the 2 wire 220v system like what. Y electrician sat we have i.e. 2 110v wires to make 220v? It doesn't have to be sonoff pow any one of the sonoff that can work with the AC would be fine.
What were you intending to use to control the Son9ff? Were you using Alexa or Google Home or something else? If using with Alexa then you could get a Broadlink RM Mini and have it learn the remote for the air-conditioner.

Apparently my other message to you was not approved.  Amazon has a DEWENWILS Outdoor Smart Wi-Fi Outlet Box, Heavy Duty 40A 120VAC 2HP Wireless Controller Timer Switch for Pool Water Heater SPA, Compatible with Smart Phone, Alexa, UL Listed.  This appears to be a Wi-Fi switch and contactor built into a nice box for $69.00.   If you are not willing to spend that then you are probably out of luck.

Again, this will not turn the unit on but if you want to limit the times that it can be turned on this will do that. 

My comments keep getting blocked.

Search for "Outdoor Smart Wi-Fi Outlet Box" on the world's biggest online retailer site.  The $69.99 item you find looks interesting.

Hello, I would like to know if anyone made it work for the 220v (two line and one ground) ? I’m looking to buy the SonOff pow R2 to use it with my 220V A/C Unit.


Does your AC unit have electronic controls?  Do you push a button to start it or does it have an old fashioned mechanical switch?

If electronic, see the comments above.

The diagrams in  on the first page will allow you to switch a US style 240V circuit safely.

Yes, my A/C unit has a button that i have to push to start it. I saw the diagram that you mentioned but I don’t know to much about the electricity  do you think that it could work if I connect it this way (line 1 to L), (line 2 to N), (Ground to E) ?

If your unit is electronic it cannot be switched on via the power cord.  It will remain off when power is applied.  You can test that by manually unplugging it while running, wait 10 seconds, and plug it back in.


Switching off one line and leaving the other hot, which is what you described, is not recommended.

I did the test that you said and the A/C unit turn on when I plug it to the power without having to push any button. You said it’s not recommended but it can work and if I connect it the way that I told you all the SONOFF POW R2 functions will be available ? I just looking to synchronize Sonoff Pow R2 with my thermostat using the IFTTT feature and make Sonoff Pow R2 turn ON or OFF my A/C unit when the thermostat request it through the IFTTT app
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