A/C on shore power trips breaker after 30 minustes

valhalla360 wrote:
Where are you looking at the breakers (pedestal or internal panel)?
- If the pedestal, you should be plugging into the 30amp outlet. A 20amp might work but it's marginal. It's not separate for the microwave.
- If it's the internal breaker panel (inside the RV), the 30amp should be the main breaker that kills power to all the other breakers. They often don't do a good job of labeling.

Are you trying to run the microwave at the same time as the air/con? If yes, there's your likely problem.

Easy way to check if it's the microwave breaker is to flip it off. If the clock on the microwave goes off you found the microwave breaker.

What is the voltage arriving at the RV? It's relatively common for park voltage to sag during peak demand on hot summer weekends. As voltage goes down, amperage goes up to compensate. Especially if the aircon breaker is getting weak, this could be enough to pop it. (The generator is only servicing your RV, so voltage should hold up fairly well).

It is just the internal breaker. The RV is in my driveway. I just replaced the extension cord (50 ft) with a heavy-duty gauge wire. I did feel the connection on the smaller cord where it connects to the adapter and it was warm. Maybe that smaller wire created too much load along with the A/C. Nothing else is running. The 30-amp breaker is for the whole RV. The rest of the breakers are all 15 amp. I have not tried the A/C with the larger cord. I think that may have been the problem along with the 99-degree heat here in CA. I am about to go turn on the A/C with the heavier cord to see if that was the problem. It takes about 20 minutes before the breaker trips.

wpatters1229 wrote:
What could be the difference between shore power and generator power?

Could be VOLTAGE.

What is voltage on that 20 amp shore power with extension cord with the A/C running?

Do you have an ATS? If so, have you checked that the connections are clean and tight and that the wires are not burned?

One other thing. I have an extension cord going to a 20 amp wall socket that hooks up to my 30 amp cord using an adapter. It has never been a problem. Especially since the load is less than 20 amps. Still confuses me how my generator puts out the same AC 120 volts to the same circuits and the AC runs as long as needed. What could be the difference between shore power and generator power?

Where are you looking at the breakers (pedestal or internal panel)?
- If the pedestal, you should be plugging into the 30amp outlet. A 20amp might work but it's marginal. It's not separate for the microwave.
- If it's the internal breaker panel (inside the RV), the 30amp should be the main breaker that kills power to all the other breakers. They often don't do a good job of labeling.

Are you trying to run the microwave at the same time as the air/con? If yes, there's your likely problem.

Easy way to check if it's the microwave breaker is to flip it off. If the clock on the microwave goes off you found the microwave breaker.

What is the voltage arriving at the RV? It's relatively common for park voltage to sag during peak demand on hot summer weekends. As voltage goes down, amperage goes up to compensate. Especially if the aircon breaker is getting weak, this could be enough to pop it. (The generator is only servicing your RV, so voltage should hold up fairly well).

I just looked at the circuit breaker and the one that trips is 20 amp and next to it is a 30 amp breaker. The tags on the power door say the 30 amp should be for the A/C and the 20 Amp for the Microwave. Maybe that is the problem? What is weird is we have never changed anything with the electrical panel and have had this unit since 2010. Could it have really been wired wrong and now decides to fail? Does the Microwave only need 20 amps?