Automatic Transfer Switch problem

Open the ATS and check for burnt contacts, wiring etc. To be really sure wire nut the gen wires to the CB panel wires at the ATS and check the A/C.

Which generator do you have? Just checking to see if you have you checked that both breakers on in the ON position no your generator?

The breakers was also my first thought, but since you bypassed the AT switch and it worked, that’s probably not it. I’m assuming your Genny puts out 44amps and you’re not exceeding capacity? Mine will only run 2 of my 3 AC’s. If you’re comfortable digging into the ATS, you can cut off power and look at the Genny side solenoids to make sure the contacts are clean. Barring that, it’ll need replacement. I had to replace mine 2 yrs ago (rig was 6 yrs old) got the same one installed in my rig off Amazon. Pretty straightforward replacement.

Alraz24 wrote:
Generator will still run, but produce no power

This statement is saying that the air conditioner has tripped the generator's breaker by drawing too much current. You have too much air conditioner and not enough generator. Adding an Easy Start to the air conditioner MAY help. Then again, it may not, depending on the size of the air conditioner and the size of the generator. My Honda EU2000i generator runs my 13,500 btu air conditioner with Easy Start installed near sea level just fine, but at altitude, it still fails.

30 or 50 amp RV
On a 30 the generator often has TWO circuit breakers one 20 amp one 30 amp

The 20 is for the AC and nothing else.

wa8yxm
It is a 30 amp. Can't see where it has tripped any breakers. When the ac wont run on generator when going through the transfer switch and then I plug it into the plug I wired to the generator out put and did nothing else, such as reset any breakers, it would seem to eliminate any breaker problem.

You have a 30amp rv,
But what is the wattage rating of the generator, make and model # would be helpful, if its over 4000w, and built in, it has (2) circuit breakers on the generator and is wired to the second lesser rsted 20 smp breaker, you are bypassing that breaker snd powering everything from the breaker meant for just the appliances and outlets
Just because you can't see it, doesn't mean it isn't tripped,you should manually reset both breakers that are on the generator, posting make model and year of the RV might help, someone will know if there is switch you missed, hidden in a closet, or under a cabinet, maybe in the bedroom,
I once had a Komfort Brand motorhome with a switch in the bedroom Closet to change the a/c from shore power to generator power

Alraz24 wrote:
My Ac will not run off generator. It runs fine off shore power. When trying to run off generator the AC will try to come on and then shut down to only fan working. Generator will still run, but produce no power and AC fan will run, but no compressor(just warm air)then later it will produce 120 volts again but, no ac compressor. Thought it might be automatic transfer switch so I wired a female plug end to the out put of the generator and plugged my shore power line in to it. AC and generator all runs fine. Do I need a new transfer switch?

Thanks

Mike

If you have a pass-thru type inverter, it may be (as it’s designed) disqualifying the generator power (seeing the generator source as substandard), but only when the heavier load compressor attempts to start, this while the air conditioner fan remains operable…

3 tons -

It kind of sounds like a ATS problem. But I would try hooking the generator back up to the the ATS and check again. When the AC stops cooling don't turn anything off. Leave the AC on and the generator running. Flip both generator circuit breakers off. Make sure they are fully off, you might have to push extra hard in the off direction on one or both of the breakers. Then flip the breakers back on and see if the AC comes back on.