Onan on board Gen - transfer switch bad?

When on board generator is running, A/C and microwave stopped working. I've checked the breakers I know about, and wonder if my transfer switch is bad. Everything works fine when plugged into park power, and RV outlets, TV work on Generator but A/C and microwave do not come on.

MTPockets, several of us have had burnt or crossed wires in the transfer switch. I have a Progressive switch and all the wires were burnt due to cracks in the insulation. I was sent a new switch at no cost which I installed. Take the cover off the switch and take meter reading to be sure. My switch smelled burnt as soon as cover was taken off. The switch is probably behind the wall from the curb side basement door. Good luck.

Terry, did you check the 2 breakers on the front of the genset?

My 1st one smelled burnt, but the 2nd did not. Also check the J-box near the generator. Mine and at least one other member's had loose wire connections and scorched wires. This was probably the culprit for both of my transfer switches.

jbeletti said:

Terry, did you check the 2 breakers on the front of the genset?

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Duh? ..... No I didn't.. Thanks Jim.. I just checked and one was tripped. However, it won't reset to on. I turned off shore power and tried to reset both with gen on and off, so, I am now assuming a bad breaker. If so, does Onan sell that part? The manual says to call an electrician if breaker fails.

Terry,

I've never heard of one going bad, but this may be the breaker you need (LINK).

Might be a problem on the generator input side of the transfer switch or with the contactor on the genny side.

danemayer said:

Might be a problem on the generator input side of the transfer switch or with the contactor on the genny side.

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Transfer switch is suspect... I've used the gen only a couple times for maybe 30 minutes all summer. In early June, my surge protector failed and while waiting for new Progressive to arrive I was plugged in at campground when sound like popcorn started coming from inside area of charger and transfer switch. I turned off power at pole and campground owner found a bad plug on pole, which he replaced and my popping did not reoccur. However, contacts may have been damaged at that time; that's why I'm suspicious. If Transfer switch us bad, would that prevent breaker on gen from switching on?

I was thinking that a bad contact on L2 might cause a voltage drop and a corresponding increase in amps that could trip the breaker. I suspect L2 because L1 has to have reasonably good voltage to actuate the contactor.

Try turning off the main and individual breakers in the coach circuit breaker panel and see if the generator breaker will reset. If it works with no load, turn off the working breaker on the generator so you can test voltage coming out of the suspect circuit. In the coach breaker box, turn on mains and a single outlet breaker and measure an outlet between hot-neutral, hot-ground, and neutral-ground. If you're not getting very close to 120/120/0, that indicates a problem. You might have to try several breakers to find one that is using L2.

I replaced my Progressive transfer switch, only because of the low voltage popping noise from the relay a few months ago. The breaker still would not switch on, so I replaced the breaker and everything now works fine.