Rear A/C Trips Breaker on the Generator

[datedd]

I also posted this in the Technical Forum:

I have a 1993 Pace Arrow 33L. It has the Onan Marquis 7000 Generator. When I run the rear A/C, after a short while, it trips the breaker located on the genset. When I run the forward A/C on the generator, I have absolutely no problems. I am assuming the front one runs off the breaker in the coach.

So I am thinking it's a bad breaker, on the genset, because I have no other problems with electricity in the coach running the front A/C or any other device. OR is it the rear A/C that's the problem?

Thoughts?

[Bob_C]

Probably the run capacitor in the rear one fading away........

[deandec]

Does the tripped breaker occur while both AC units are running at the same time?

Sometimes the 30A is not enough to run two AC units.

[twinboat]

Originally Posted by deandec

Does the tripped breaker occur while both AC units are running at the same time?

Sometimes the 30A is not enough to run two AC units.

Its a 7000 watt generator. That's almost 30 amps per breaker. One AC will be on each side.

[Solo_RV_Guy]

Originally Posted by deandec

Does the tripped breaker occur while both AC units are running at the same time?

Sometimes the 30A is not enough to run two AC units.

He's got the Marquis 7000. That's a pair of 30 amp, 120V lines.

[datedd]

Originally Posted by deandec

Does the tripped breaker occur while both AC units are running at the same time?

Sometimes the 30A is not enough to run two AC units.

Yes the genset circuit trips when both are on.

[twinboat]

When the breaker trips, does the front AC keep running ?

[Isaac-1]

My bet is on either a bad capacitor in the air conditioner, or the compressor is going out and drawing too many amps.

[johnhicks]

Let's approach it from the other direction. I'm assuming you have a 30A coach and when plugged in you can select front or rear AC? If so, does the rear AC trip anything when you're plugged into CG power?

[Xmcdog]

Originally Posted by Isaac-1

My bet is on either a bad capacitor in the air conditioner, or the compressor is going out and drawing too many amps.

Dirty condenser will have the same effect.

[chboone]

When the breaker trips does other things you are using also lose power? The breaker may be tripping because of additional load on that circuit. Only way to know if the A/C is tripping the breaker is by checking the amp draw at the breaker panel inside the motorhome. Also check for any lose connection.

[twinboat]

Bad capacitor or dirty condensor should trip the 20 amp breaker in the panel, not the 30 amp one on the generator.

There's more to the story.

[johnhicks]

With rigs this old what seems logical isn't the way it is. In my 1993 HR DP I have a switch for front or rear AC while on shore power. On generator, I have a 30A breaker on the gen and a 30A breaker on the panel. However, the gen also puts out 20A on a separate circuit that powers the rear AC only. The only breaker is on the gen; it doesn't go through the panel, and if that 20A breaker is off then the AC is off. To make things even odder, I have a 30A transfer switch. It appears that the gen provides power to the rear AC directly, which is exceedingly strange since shore power could perhaps also power the rear AC at the same time or the gen could backfeed.

Of course there's no mention of any of that in the MH docs.

At any rate, and to the point, my front a AC had developed a habit of popping the 30A gen breaker regularly. I replaced the AC for other reasons and it hasn't popped the breaker in a year.

[datedd]

I installed a Superboost hot start device to the capacitor. I ran the rear AC for an hour. No more tripping the breaker.