Struggling with wiring mini splits on a timer that can handle 30 amp up to 220 – any advice for my 20 amp, 120 volt system?
Asked by Hannah Pena 
3 months ago
Last Updated: August 29, 2024
Hey guys, I’ve got some mini splits that I’m trying to set up on a timer. It’s rated for up to 30 amps at 220 volts, but I’m having some trouble getting them wired correctly. Just to clarify, my mini splits run on a 20 amp breaker and are 120 volts.
So, what seems to be the problem?
Remember, only switch the hot side!
So, why not go for a smart programmable thermostat instead?
I understand the issue now. My apologies. It’s a single pole contactor that can be either normally open or normally closed
Identifying screws 5 and 3 as the hot and switch leg is crucial. There might be external control screws on top, but controlling them with a timer could affect performance. Found more details on Amazon: screws 1 and 2 are for power and neutral, 3 is common, and 4 and 5 are switch legs. Also, it’s din rail mounted. Are you setting up a control cabinet or leaving it as is?
Just opt for a regular 120v timer instead
Avan Childress because I’ve got 30 ministers that I need to set on a timer
The top screws provide power to the timer. The input voltage ranges from 85 to 265. The timer is actually correct for 120v as it only breaks one leg on the load side, making it single pole.
Whether you use a 110 or 220 timer doesn’t really make a difference. Air conditioners can handle more amps than that timer. You need to connect a magnetic 220 30 amps and then let the timer control the magnetic.
Seems like we’ve got a landlord trying to limit their tenants’ AC usage 😂
Not a slum lord, my tenants always forget to turn off the AC when they leave and these minisplits don’t have a thermostat so they just keep running and freeze up, then I end up with a crying tenant wondering why there’s no A/C
Which mini split doesn’t come with a thermostat? The one I have in my basement is just set to auto and then forgotten about
The contacts for this single pole double throw are rated at 30 amps with a coil rating of 120, 208, or 240.
I’d suggest checking the unit’s instructions. It might not be a good idea to proceed this way. A programmable thermostat would probably work better
I actually have four minisplits and all of them come with a built-in timer…
This might seem like a strange way to do it, but feel free to share your experiences here: https://.com/groups/electric.clusterfuk/
Best of luck to you!
It’s highly likely that messing around with the control board in the unit will cause issues. This method is very inefficient and could potentially damage the board every time the contactor closes.
Make sure to connect the timer to the 24vac control wiring, not the main power! If the thermostat loses power, its programming will be ruined due to premature battery depletion
I suggest getting a thermostat instead of a timer.