Onan 5.5 wiring

[jdross440]

My 2007 Raptor 3712TS has the Onan 5.5 generator factory installed. My question is about AC wiring to the trailer. It appears that only one of the 30 amp breakers on the generator is wired into the breaker/fuse box. The reason I say this is when I run both air cond and the water heater electrical comes on after a couple minutes one of the 30 amp breakers trips. Same thing happens if I plug in something that pulls about 1000 watts to any of the outlets inside. Is this the way it is or do I need to do some wire tracing?

[cardinal96ss]

I certainly recommend wire tracing which should be fairly easy by pulling the breaker box out and also opening the electrical box on the generator. But my guess is that the generator was installed properly and the problem is that the RV electrical loads are not balanced between the two positive lines.

[MattHelm21]

This is base on a lot of assumptions but I would expect this to be normal. One of the A/C's if you have 15,500 BTU units pulls about 20 amps by itself. I don't know what model hot water heater you have but 10 amps seems to be a common rating. I would expect the water heater and one air conditioner to be wired to one breaker on the generator and the other air conditioner and appliances to be wired to the other breaker. So AC plus Water heater equals about 30 amps and trips the breaker.

[jdross440]

When the breaker trips both A/C's go off as does the water heater and refrigerator (refrigerator and water heater are on same breaker), the 2 110 volt lights and the wall outlets I have checked.

[cardinal96ss]

Again, it sounds to me like some re-distribution of loads is in order. Both A/Cs, water heater, refer, lights and outlets all drawing on the same line?? Wow. At a minimum I recommend separating the A/Cs, one with the refer and the other with the water heater. Worry about the lights and outlets after that is accomplished.

[cardinal96ss]

OK. After thinking a bit more about this, and since you haven't mentioned any problem with the breakers in the RV panel when hooked to shore power, it has to be the way the generator feeds the panel. It's as if only one of the generator leads feeds the transfer switch. You should be able to trace both black and red lead power from the generator, thru the switch, and at the panel. A voltage check at the input to the transfer switch with the generator running should indicate 110v on each of the leads from the generator. (Your generator breakers then should be able to individually break power an each lead. ) A check on the switch output then should indicate power to the RV breaker panel. That panel doesn't have a choice of its of the power.

[jdross440]

You are correct that I have no problem when connected to shore power. I can pull a panel in the basement storage compartment and get to the back of the breaker panel and converter. I will have to track wiring from the panel to locate the transfer switch as I don't know where they hid it then track from there to the generator.

[jdross440]

I figured out my problem. I got into the breaker box and found that all the high current draw items are on one side of the main breaker, 50 amp on each leg which is ok if your running off of shore power. But when running on generator it's limited to 30 amp on each leg. With both A/C's, water heater/refrigerator and the outlets on one leg it overloads that breaker. The other side has the microwave, cargo/toy section, GFI outlets and converter which loads it relatively lightly. I am going to move the #2 A/C to this side and move the cargo to the side the #2 A/C was on.

[cardinal96ss]

Congrats. That should take care of it. Enjoy your next trip.

[roadglide]

I had a problem today with the back AC and microwave not working when I was running the 5.5 generator,every thing worked on shore power. There was one 30 amp breaker that ran the microwave and back generator off at the onan. I got it back from a dealership that way . All is good now.