A/C and an inverter

[moresmoke]

How big of an inverter would be required to start a 15k btu a/c? I'm not interested in the 12v supply debate, just need to know how many Watts to start the unit. 2500 continuous/5000 surge?

[3_tons]

christopherglenn wrote:
Isn't that in my signature?
Batteries 3 PVX-840T.
Inverter XANTREX FREEDOM SW3012.

I said it would run it, just not for long. More of a proof of concept, for a day where I have 2+ kw on the roof.

I appreciate your kindly reply.

[moresmoke]

Thanks for the replies, sorry I couldn't check back in sooner, work does that some times. I will look for something in the 3-6k range.

[christopherglen]

Isn't that in my signature?
Batteries 3 PVX-840T.
Inverter XANTREX FREEDOM SW3012.

I said it would run it, just not for long. More of a proof of concept, for a day where I have 2+ kw on the roof.

[3_tons]

christopherglenn wrote:
My inverter is 3kw running 6kw surge. I can start either AC on it, and if I start one, wait until it is up to speed for a few seconds I can start the second one. FWIW I am just under 3kw running both.

What make and model is your inverter, and what type and number of batteries??

Thx
3 tons

[bcbigfoot]

My cheapo 160$ Canadian tire 1000 watt PSW inverter fired up and ran a Dometic 7200 btu AC, I only ran it for 15 minutes, this was when it had new group 31 agm batteries and only did it the one time. The AC pulled approx. 700 watts if I remember correctly.

[christopherglen]

My inverter is 3kw running 6kw surge. I can start either AC on it, and if I start one, wait until it is up to speed for a few seconds I can start the second one. FWIW I am just under 3kw running both.

[JiminDenver]

I understand the OP's desire. I've gone to considerable lengths to be able to have A/C without a generator in the rare times we need it and that's just a little 5000 BTU window shaker.

[MrWizard]

the thread is NOT about generators
i do agree that is the ideal option

[hbillsmith]

Simple. Just get a Champion 3100 Inverter. Choose the manual start about $750 or choose the electric remote start about $900. It will run a 15K A/C just fine. A smaller 13.5K A/C is even easier. Don't plan on running a microwave or hair dryer at the same time though. Just turn the A/C off for a few minutes if you need to run either. If money is no object, feel free to go for the Honda or Yamaha. All 3 are quiet at between 53db to 58db.

[MrWizard]

it will take about 1400VA to run
12amp at 120v
the problem is the start surge, and how hot is it, when you push the button
a 3kw might start it at 80F in the shade
while at 101F in the sun you will need a 6kw
the LRA lock rotor amps on the compressor will be much higher at high temps and restarts as much as 50~60 amps
the tag on the compressor will tell you the LRA

[KJINTF]

There are ways to eliminate the voltage sag exhibited by LA batteries
Check out a LiFePo4 battery system for the house battery bank

[greenrvgreen]

I ran my Dometic 13.5k regularly off my Prosine 2.0 and four (4) gc2 batts. I now use a 5k window unit and it is so soft-starting that I can't even read a surge on my meter.

As others have said, the batts are the crux and nobody wants to hear this. It's not a question of how long you can run the AC, but whether the Peukert effect of the surge will drag the voltage down below your inveter's shutoff level. The only cure for this is more batteries.

[2oldman]

smkettner wrote:
I would be looking at 24v supply if doing this on a regular basis.

Yah. My batteries/cables would get hot after about 10 minutes of run time @ 12v.

[wa8yxm]

3000 to 3500 watts is your answer I think

Though I would not wish to guarantee that

But 30 amp service is only 3600 so 3000 SHOULD do it I would think since I can usualy run both the water heater and one A/C on 30 amps.

2500 MIGHT but that's cutting it too close for comfort and I have heard of it being done on 2000 but that was a very easy start A/C.