18k BTU mini split on 4kw genset w/ step up transformer?

JasonB.

New Member
Joined
Jun 10, 2024
Posts
3
I've currently got an old rooftop unit that I'd like to get rid of and replace with a mini split. I'm handy, but I'm not an electrician. Will this work? I know I can go with a 12k BTU, but I'd really like the bigger unit. There's really no insulation on the bus, and it gets pretty hot here in North Alabama. Sometimes bumping 100 degrees or more.

Mini split

Step up transformer
 
I think you are limited by voltage to 12k. After that it goes to 240V.

What voltage do you have?
 
The transformer in your link says it won't work in the USA.
 
Good afternoon, I installed a dual zone, 2 ton mini-split, in my Thomas. I had a hydraulic shop make hoses instead of using copper. Almost all 2 ton a/c units will pull 16 amps at 240 vac. That's 8 amps per leg. My Honda 3000iu generator only puts out 23 amps at 120vac. I installed a 5kw transformer between the generator and the outside a/c unit. it takes 120 volts ac and turns it into 240 volts ac. It work's just fine, with a little power left over. I hope this helps you out. have a nice evening.
 
That step-up transformer is too rinky-dink for your planned minisplit. I have the 12KBTU 120VAC version of that minisplit, works quite well. It has soft start and draws about 16 amps at full cooling power.

But like you said, the 12K will only go so far.

What's your power source?
 
I've currently got an old rooftop unit that I'd like to get rid of and replace with a mini split. I'm handy, but I'm not an electrician. Will this work? I know I can go with a 12k BTU, but I'd really like the bigger unit. There's really no insulation on the bus, and it gets pretty hot here in North Alabama. Sometimes bumping 100 degrees or more.

Mini split

Step up transformer
The concept will work. You will need a larger transformer than the one you have selected, From the amazon ad:->[Max - 5000 watt for 30 minutes Use. For continuous use: 2500W. Make sure you multiply x 2 the wattage of your item and get a transformer bigger than that]
You might want to check with Senville in regards to the voltage input. The transformer you have selected is single phase 220V. The Senville unit may be looking for split phase.

We did something similar using this Victron auto transformer:
Victron Autotransformer 120/240V-100A

We used it to take the 30A 110V single phase output of our RV ready champion generator and step it up to 220 Split phase. It ran the 18K mini-split just fine. I know it is more than twice the price of the transformer you have selected, but it is several times the utility and capacity.

You might get away with thier 32 amp version which is a hundred dollars cheaper, But you would be better of paying the extra hundred bucks for the 100A unit.

When we bought ours it was 800 bucks.
 
That step-up transformer is too rinky-dink for your planned minisplit. I have the 12KBTU 120VAC version of that minisplit, works quite well. It has soft start and draws about 16 amps at full cooling power.

But like you said, the 12K will only go so far.

What's your power source?
I'm currently using an old Onan BFA4.0 generator off of the RV that I used as the donor for my schoolie conversion.
 
The concept will work. You will need a larger transformer than the one you have selected, From the amazon ad:->[Max - 5000 watt for 30 minutes Use. For continuous use: 2500W. Make sure you multiply x 2 the wattage of your item and get a transformer bigger than that]
You might want to check with Senville in regards to the voltage input. The transformer you have selected is single phase 220V. The Senville unit may be looking for split phase.

We did something similar using this Victron auto transformer:
Victron Autotransformer 120/240V-100A

We used it to take the 30A 110V single phase output of our RV ready champion generator and step it up to 220 Split phase. It ran the 18K mini-split just fine. I know it is more than twice the price of the transformer you have selected, but it is several times the utility and capacity.

You might get away with thier 32 amp version which is a hundred dollars cheaper, But you would be better of paying the extra hundred bucks for the 100A unit.

When we bought ours it was 800 bucks.
Thanks for the input, and the link. Quick question here. The 1800 BTU units I'm seeing seem to be ~2200 watts or less. So, my original thought was that 2500 watts continuous should be plenty. Are you saying that I should be looking for 4400 to 5000 watts continuous? Thanks.
 

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top