Community Forums

Bucky1320 · 08-10-2018, 10:22 AM

I noticed that both of my air cons are on one side of the breaker panel. This is a 50 amp panel.

When running the onboard onan 6300, it will run both air cons without issue. I BELIEVE the onan outputs only 110V power.

When I run my 6500 portable generator off the twist lock, 220V, 20.3 amps per leg two 120V legs, to a 50 amp adapter, I can only run one air con. When I start another, the generator will trip it's breaker. I suspect that both airs are pulling on one leg of 120V power, and tripping that leg. I also suspect that if I move one breaker to the other side of the panel, all will be well, as it ought to be using the other leg.

Is this how RV breaker panels are wired? Is load balancing helpful in these situations?

Soppy · 08-10-2018, 10:34 AM

The loads should be balanced , but most times they are not . Moving the A/C breaker to the other leg will solve the problem of tripping the breaker on the portable generator , providing there is little or no load on it presently. A 120 v generator won't care , but a 120/240 v unit will be overloaded on one leg.

Roy1 · 08-10-2018, 10:37 AM

I would agree with your suggestions. If it were mine I would have the 2 on separate legs. Should be easy to do just make sure the other loads are balanced.

CountryB · 08-10-2018, 10:39 AM

That's the way my panel is split. Front AC on one leg and Rear AC on the other.

Bucky1320 · 08-10-2018, 11:52 AM

I will try running each air con separately and clamp monitor the 50 amp cord wires to see if they both pull on one. Seems silly that they would have put them both on one from the factory. but those factories do some silly things. I may be able to see easily with the cover off too and trace it. The washer/dryer seems to be on the other side. That's never used....so easy swap.

MtnTrek · 08-10-2018, 03:12 PM

Agreed with load balance, but...

Silly factory might have done it so you could run them, alternating them, connected to a 30 amp service on L1. Some RV's have an optional load management switching device to accomplish this feat on 30A shore power.

Since L2 probably doesn't have service except on 50A service.??

BTW: many Onan models are only mono-phase, 115V <5500W, the 6500W commercial (white case) has 220V potential between L1~L2

Bucky1320 · 08-13-2018, 10:00 AM

I'm not sure how 30 amp service runs honestly. There is power to both sides of the distribution panel. And you can see each leg coming in on opposite sides. That's a bit perplexing to me. It's just a matter of my ignorance about how the adapter is wired I think.

I tried moving one ac to the other side of the distribution panel, and the result was identical. I have noticed that even one AC can trip the generator if it is on econ mode. That's kind of a bummer since you don't want to run that thing wide open all night just to accommodate the ac cycles.

Another thing I noticed is that the onboard onan will run both without issue. Even kicks the compressor quicker. I may check the voltage output on the portable. I usually see about 123V with the Onan. Sometimes the start up can be pretty hard even running on the Onan though.

Bucky1320 · 08-22-2018, 03:16 PM

I did some testing after moving one breaker to the other side of the panel. With the clamp on, you can see that each ac unit is now pulling from a different leg. I figured I would give an Easy Start a try, and what a difference. We will see what running in the hot weather and restarting an AC is like. But it really starts a lot easier now.

Old Scout · 08-22-2018, 03:58 PM

…..maybe not so much for newer coaches with energy mgt systems but for older coaches, load balance is an issue...but it is not just about ACs....you have inverter/charger, water heater, clothes dry, microwave, etc that draw lots of amps....doesn't take a lot of math to figure out that you can quickly push 50 amps on a single leg of 50 amp service; and certainly runout of amps when a single 30 amp leg is divided across the entire grid in your rig. I am sure we all have opinions on what appliances should be on one leg vs the other, but sooner or later you run our of available amps to "balance."
Reference other posts--it is pretty well agreed that running two "avg" AC units on 30 amp service is at the limits of the system--I could see in an older rig where the builder might put both AC units on one leg to keep you from trying to run two units at the same time while on 30 amps--times have changed a bit since 1999.....so I am told [smile]

vsheetz · 08-22-2018, 04:28 PM

Every other full circuit breaker slot should be on same leg.

Your two air conditioners should be powered by different legs. If not, suggest to make them so.

Bucky1320 · 09-26-2018, 10:38 AM

Quote:

Originally Posted by Old Scout

…..maybe not so much for newer coaches with energy mgt systems but for older coaches, load balance is an issue...but it is not just about ACs....you have inverter/charger, water heater, clothes dry, microwave, etc that draw lots of amps....doesn't take a lot of math to figure out that you can quickly push 50 amps on a single leg of 50 amp service; and certainly runout of amps when a single 30 amp leg is divided across the entire grid in your rig. I am sure we all have opinions on what appliances should be on one leg vs the other, but sooner or later you run our of available amps to "balance."
Reference other posts--it is pretty well agreed that running two "avg" AC units on 30 amp service is at the limits of the system--I could see in an older rig where the builder might put both AC units on one leg to keep you from trying to run two units at the same time while on 30 amps--times have changed a bit since 1999.....so I am told [smile]

I think I started the confusion with this. But I am running off of a 50 amp plug with a converter to a twist lock. The generator is providing two legs of just over 20 amps.
I moved the other air to the other side, and now, as long as I run the fans before starting the compressor, I can run both at once. it even quiets down a bit in econ mode, so it is maxing out the generator. Kinda cool!