30A Circuit Breaker at house tripping

OP- One interesting piece of info would be to measure voltage IN the coach, AT the plug into the motorhome, and then AT the house breaker panel ?

Mine is a 50A coach, but that doesn't matter in this case as both of us are drawing the same load from a 30A circuit, and my drop isn't anywhere close to yours. FYI- I'm using 10ga to a Twist-lock on about 80' of 10ga, into a twist-lock ton30A RV dogbone, to a 30-50A RV dogbone. At 106 temps and both compressors turning, NO fridge (it's on LP), things are all consistently warm but nowhere near hot, and dropping <4v IIRC; sounds like you're is twice this. This is essentually a temporary setup and only used when it's at the house. I expect yours is similar or better (?) as that's a long run on the extension, but it works fine for what I built it for. If yours can't do this, sart looking for excessive heat, including the coach ATS, internal panel, and back to the house

time2roll wrote:

Janss wrote:
I wish Winnebago had made this a 50AMP coach, but alas, it is only a 30AMP coach. We've always had to be careful about turning things on while a/c is running. But have always been able to run the frig with it...just not other stuff.

Could spend the money on an upgrade. Only hard part is pulling new 6/3 romex from the inlet to the new breaker panel through hidden areas. The rest is not hard, just tedious.

Or some have broken out the second air and connected to a separate cord.

There's miles of forum threads on dual power adapters and not hard to do for having a separate circuit to the rear a/c, like you're saying.
That's what I did with our old gas coach and always plugged the rear air into a separate outlet on the campground pedestal. Plugging it back into the outlet for where it was split in the coach, put it back like it was and a very easy and simple operation.

Janss wrote:
Motorhome plugged in full time. Temps outside around 100-105 degrees. MH basement a/c running constantly during the day. Except when the circuit breaker trips :( I'm talking about the one on the side of my house, not inside the motorhome.

Panel inside MH shows 26 or 27 amps for a/c and frig.

Breaker doesn't feel loose or worn to me. 30amp plug looks okay, not melted. Why is the breaker tripping? Because the circuit is getting too hot, just because the a/c is working so hard due to the hot weather?

Could be the breaker has some fatigue.
Even at a constant 30amps, some may never trip.
Momentary inrushes, during startups and such, should have no effect unless the curve has been affected with some fatigue as well.
You didn't say whether or not you had an EMS for managing your load, but if you're not ever exceeding 30amps, then it shouldn't make a difference.
Does the breaker feel extremely hot to the touch?

Janss wrote:
I wish Winnebago had made this a 50AMP coach, but alas, it is only a 30AMP coach. We've always had to be careful about turning things on while a/c is running. But have always been able to run the frig with it...just not other stuff.

Could spend the money on an upgrade. Only hard part is pulling new 6/3 romex from the inlet to the new breaker panel through hidden areas. The rest is not hard, just tedious.

Or some have broken out the second air and connected to a separate cord.

Thanks for the additional input. I think I'll change the breaker to start. I believe it already is in a good position...noting the various comments about getting as much air as possible (or away from as much heat from the other breakers as possible). And in the meantime investigate the voltage issue, taking notes from all your comments.

down home....Inside the MH, each air compressor has its own 20amp circuit breaker. I wish Winnebago had made this a 50AMP coach, but alas, it is only a 30AMP coach. We've always had to be careful about turning things on while a/c is running. But have always been able to run the frig with it...just not other stuff.

As your readings testify and everything else you said Your system is losing voltage due to higher loads and not the coach.
The Hughes autoformer and others would help but going to 50 amp should stop the drop, to the 108 volt area.
The 50 amp box and heavier wire would be the better fix.
Someone else might know for sure but probably one ac is on one 50 amp circuit and the other ac on another 50 amp circuit in the coach. So the fifty amp box would put each ac on its own circuit again to the box.
Ours combined usually run in the 23 amp range, with fridge, tv and lights continously but can rise to 27 amps sometimes. The other day the gen sounded like it was running away, the panel said 43 amps. Someone had accidentally pushed the engine heater switch to on.

As your readings testify and everything else you said Your system is losing voltage due to higher loads and not the coach.
The Hughes autoformer and others would help but going to 50 amp should stop the drop, to the 108 volt area.
The 50 amp box and heavier wire would be the better fix.
Someone else might know for sure but probably one ac is on one 50 amp circuit and the other ac on another 50 amp circuit in the coach. So the fifty amp box would put each ac on its own circuit again to the box.
Ours combined usually run in the 23 amp range, with fridge, tv and lights continously but can rise to 27 amps sometimes. The other day the gen sounded like it was running away, the panel said 43 amps. Someone had accidentally pushed the engine heater switch to on. Would not have known plugged in.

Change the breaker if tripping at less than 30 amps.
If the panel has extra slots then move them around so the 30a breaker can get some air.

OP: You mentioned turning on the fridge. You are running it on 120V or LP ? On really hot days I seriously doubt a 30A CB will support both compressors running AND the fridge on elect.

If you are maintaining 24A and the breaker still trips, consider changing it. The one I bought 2 weeks ago cost me less than $4 @ HD.

Also, I purposely installed it at the bottom of the panel so its not cramped in with other heat producers, and the breaker on top is typically a light load. Every little bit helps..

I would suggest that you start checking from the outlet that you are plugged into, through the MH feeder breakers, for loose, over-heated connections. Especially the shore power cord plug. Take I apart and inspect the actual internal connections for looseness or overheating. This will cause the low voltage. If you have low voltage at the house outlet, call your electrical supplier to be corrected. Do these checks with the breaker turned off. If there is discoloration on any connections, trim the wire, if there is enough wire to do so.