AC Problems

[karollins1]

HI All,

I took my 2020 cougar half-ton 22rbswe out dry camping this past weekend. I tried to run the AC of of my 3500w inverter, but it would only run for a minute or two then trip the breaker. I have a 15k dometic AC and I was looking for a hard start capacitor. Any suggestions?

[KimNTerry]

Well, unless you have a really awesome battery bank and the ability to replenish it relatively quickly (Generator or lots of solar) your AC won't last long on batteries with inverter anyways. Not all 3500 watt Inverters are created equally either. There may still be too much amp draw when the AC goes to start.

As to a hard start capacitor, I bought one of these
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

6 yrs ago and it still works great. Note I have a 13.5 K BTU air conditioner so YMMV. I can run my AC of of a 20 amp plug or just one of my generators if required (as long as nothing else is running). I usually use both generators in parallel if trying to run AC off of generator though.

The other option to aid in starting an AC is a soft start kit, which is quite a bit more expensive but I have heard more efficient as their is software involved that learns your loads and manages them better. Only you can decide if $300 vs <$20 for a hard start capacitor is worth it.

Last I looked, my trailer has wheels and I try to camp where I don't need Air Conditioning.

[karollins1]

Thank you. I guess I should have clarified, it is a 3500w generator/inverter that doesn’t run the AC. I just put that start capacitor in my Amazon cart. Thank again for replying.

[flybouy]

Originally Posted by karollins1

HI All,

I took my 2020 cougar half-ton 22rbswe out dry camping this past weekend. I tried to run the AC of of my 3500w inverter, but it would only run for a minute or two then trip the breaker. I have a 15k dometic AC and I was looking for a hard start capacitor. Any suggestions?

I doubt that a "hard start" capacitor will solve your problem. The much load will deplete a 12 v battery in a matter of minutes. If you need/want air-conditioning then a generator or a 30 amp electric campsite are your realistic choices.

[Cougar25]

I put a SoftStart on my 15,000 BTU Coleman and I can power it with a Honda 2200I (converted to propane).

[CedarCreekWoody]

Originally Posted by flybouy

I doubt that a "hard start" capacitor will solve your problem. The much load will deplete a 12 v battery in a matter of minutes. If you need/want air-conditioning then a generator or a 30 amp electric campsite are your realistic choices.

I think the OP is now saying he as an inverter type generator, not trying to run off battery.
That generator should run the A/C if there are no other heavy loads. He needs to be sure the water heater is set to propane and check for other loads.

[JRTJH]

karollins1,

You didn't state WHERE you were camping when the inverter generator wouldn't run your air conditioner, nor did you state the circumstances of "HOW" you were powering the generator...

All generators lose about 10% of rated power every 3000' of gained altitude. Additionally, most generators that are "dual fuel" (gas/propane) will lose about 15-20% when operated on propane.

So, if you were, let's say, around 6000', running your dual fuel generator on propane, you'd be looking at somewhere around a 35-45% rated power loss.

Let's say your generator has a 3500/3100 watt (surge/continuous) rating, then a 20% reduction for altitude and a 15% reduction for propane would put you at a 35% reduced power capacity. That means your 3100 watts "continuous" is really only around 65% of that, or around 2015 watts.

Given that you were "dry camping" powering the 12 volt systems off the battery, as soon as you plugged in the generator, the converter/charger is going to "kick into high gear" to recharge the battery. At 120 volts, that's going to be around 5 amps of power drain from the generator (which is about 600 watts). That leaves you with around 1415 watts. That's clearly NOT ENOUGH to power your air conditioner !!!!!!

Do the math on "where you were camping, how you were camping, what was powering the generator and what was left after plugging in the trailer".....

Depending on the circumstances, there might simply not be a problem, other than you were expecting too much from a too small generator given the situation....

Then again, maybe you were at sea level, dry camping, running on propane, plugged in the generator when it was 110F (in the shade) and there was no way for your generator, with what else it was powering, to overcome the air conditioner's compressor "head pressure".....

Situations do matter, especially with limited power sources that are derated for dang near everything and a trailer with "hidden drains" that you weren't considering......