A/C tripping the breaker

Well, THAT was interesting!

Got down last week (post delayed a little bit) and everything was working fine. Let it run for 2 days and at 0300, the breaker tripped. I just happened to be awake so I checked. It wasn't the A/C breaker like wifey said, it was the MAIN!

That morning, I did some checking and thinking. On electric, I had the Fridge, A/C, Elec. hot water heater and an ice maker outside connected to the trailer. Perhaps a bit too much for the 30a trailer power. I decided to shut off the electric hot water and use gas. We don't use hot water that much.

Then I went and checked all connections and screws; they were all tight and fine. I cleaned the cooling fan under the power; it was a bit dusty and probably wasn't function to max ability.

Then I replaced the breaker. This Main blew several times before when I had electric heat going and some other stuff. Figured it may be weak from all the times it had been tripped. Problem is that the main was also part of the A/C breaker so I had to get a special 30/20 breaker. Not a Home Depot or electric supply breaker....as I found out the hard way. Quick trip through traffic to the RV supply and got the new breaker for $20

Installed and everything has been working for about 5 days now.

I'm guessing that all the appliances kicked on at one time tripping the breaker which would possibly explain the time between trips.

Thanks all for the help and suggestions!! Much appreciated!!!

Check the run and or start capacitor to make sure it is within it stated microfarad rating. Capacitors are my number one nuisance problem on home AC units when temps get hot outside.

Probably missed this somewhere, but perhaps you can "elaborate" on the problem some more... which might help narrow your search for a solution.
does your breaker kick off at AC startup or after a while running?

Rthomas61 wrote:
It stinks because I never had an issue and am the only one having an issue right now. Then they changed the power cables and hookups and I'm having the problem. Wish they left it alone!

Very interesting. Yes check voltage and request new work if below 110 in the RV.

It stinks because I never had an issue and am the only one having an issue right now. Then they changed the power cables and hookups and I'm having the problem. Wish they left it alone!

Rthomas61 wrote:
What would cause the low voltage? That's the first thing I'm going to check. Check that at the breaker?

The problem lies with the NEC minimum code requirements for RV Parks and which edition of the NEC the CG/RV park was built to. The NEC requirements have improved over the decades but it is simply way behind all the high demand RVs nowadays (except for owners who built above the min. code requirements). You can't fault a CG owner for going cheap on the construction.

A single 30 amp pedestal has a 3600 watt demand but when there are multiple pedestals, the demand allowance drops significantly. Say a CG had a section of all 36 amp pedestals, the total demand is calculated at just 41 percent of 3600 watts (1476 watts) as per table 551.73. So if everyone is running an AC unit in warm weather plus other loads, the CG's system simply can't handle the total load and voltage goes down as a result. Not much you can do except to get an autoformer.

If you travel around to numerous CGs, it's almost guaranteed that if you go to an older one like in the 70s, there will be low voltage.

I agree with the others, check the voltage at the source and at your load. There are many other things you can check/fix but check the voltage first.

Rthomas61 wrote:
What would cause the low voltage?

Load on the system - yours and everyone else's - excessive voltage drop from too long a cable run, excessive voltage drop from using cable inadequately sized for the task at hand. It ALL counts. ;)

Check it at the campsite post, both unloaded (i.e. before you plug in) and loaded (with everything running) AND at the camper when the circuit is under load. You can bet that if your unloaded source voltage is any less than 110 vac you can expect voltage under full load to be low enough to cause problems starting and running your A/C.

Here's a handy, easy to use Voltage Drop Calculator.

What would cause the low voltage? That's the first thing I'm going to check. Check that at the breaker?

Check the voltage before you throw parts at it...