AC Tripp’s Breaker

[Cubbie]

Hi all , sure is hot here. We have a 2018 3791RD, full time, in Arizona right now and cannot head to cooler country right now. Right now 106 outside. The living room ac tripped the breaker. Reset breaker and tripped again in about a hour. Good voltage on line. I checked for loose wires in breaker box, all tight. Changed breaker. AC ran about an hour and tripped breaker again. Breaker feels hotter then bedroom ac breaker before it trips. Mobile RV repair we use cannot get to us until next Monday. Bedroom AC does not begin to cool living room. Any suggestions for something else I can check. Beside price of local hotel!!! Did I say it was hot???

Thanks, Art

[jeffba]

are you running it on High or Auto?

[Cubbie]

Auto mode

[jeffba]

try running it on High

[ChuckS]

Couple of things I’d check are...
Get up on roof and clean out condenser
Check fan ... with power off to see if it spins easily
Stay on roof and run the air conditioner
If you hear a humming sound replace start capacitor

[Cubbie]

Good thoughts, I will get up on the roof early tomorrow before everything gets too hot to touch.

Jeffba, I tried all fan modes, all tripped breaker. Will run about an hour or so then trip.

[DQDick]

Also, make sure your return air filters are clean and the ducts are not collapsed.

[Cubbie]

DQDick, thanks. Return ducts are open, good air return and filters are clean. Every other fin trimmed off output ducts. AC starts quickly and blows cold air. When both ACs worked inside temp would be 85 with outside temp around 105. This problem just started yesterday. Living room AC will run for an hour or so then breaker will trip.

[jimcol]

I see you tightened all wires at breaker panel. Check your wire connections for tightness at the unit itself. Wire nuts can come loose.

[BB_TX]

It is also possible you simply have a breaker getting weak. I had one on my rear A/C that started tripping under similar conditions (hot weather and trip after running for 30-60 minutes) for no apparent reason. And it was only 2-3 years old. Replaced the breaker and never tripped again. Simple and inexpensive something try.


Oops. Overlooked the fact you already changed the breaker.

Two or more breakers positioned side by side and each running warm/hot can share heat and cause a breaker to trip at a point lower than its rating.

[Tom N OH]

You say the voltage is good. What is the voltage on each line with both A/C units running? Are both units wired to the same leg of power, or are they on opposite legs? Our 2015 High Country had both A/C units wired on the same leg. That was one of the first things I changed. Our 2019 Montana has them wired on opposite legs.

[jimcol]

Originally Posted by Tom N OH

You say the voltage is good. What is the voltage on each line with both A/C units running? Are both units wired to the same leg of power, or are they on opposite legs? Our 2015 High Country had both A/C units wired on the same leg. That was one of the first things I changed. Our 2019 Montana has them wired on opposite legs.

Tom, You make a good point. That is exactly how my 2006 was wired. Took about 5 minutes to change it. Balanced the load nicely.

[BB_TX]

Both A/Cs on the same leg gives the impression of unbalance and needs to be looked at. But it is not quite that simple. If both A/Cs are on leg 1, and the water heater, microwave, converter, and that outlet your wife plugs her 1500 watt hair dryer or you plug in your 1500 watt space heater are on leg 2, then it is not as unbalanced as first appears. In a case like that, if you move an A/C to the leg 2, then you may need to move something else from leg 2 to leg 1. You need to look at the overall picture.

Two A/Cs are less than 30 amps, which only a little over half the 50 amp leg.

[Cubbie]

Update: Mobile RV tech just left. Said compressor was bad. Was drawing 20.2 amps and thus tripping breaker.
Bad news is that he checked on line inventory across the country and said none were available. Dometic plants closed. He put a back order in. Could be quite a while for a new air conditioner to become available. And it is 106 today.

Thanks to all that replied. For those who talked about the ACs on same line, ours are on separate legs.

[Dhardy]

I am an HVAC mechanic. It is very rare for a compressor that is bad to run at all. I would replace the capacitor as that could be the cause of the compressor pulling higher than normal current. Also make sure that your condenser is clean ( coil on the roof that is visible from the outside) when condensers get dirty the current will rise due to higher operating pressures. Take a hose to the roof and wash the coil thoroughly with power disconnected. If you replace the capacitor be careful to pay attention to the mfd and vac ratings and get the exact replacement they are not one size fits all. Hope this helps.