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profdant139's avatar
profdant139
Explorer II
Jul 30, 2016

Can't run A/C at home: solved -- see 8/21/16 update

It's hot in Calif, and I want to use the trailer as a lifeboat -- but the a/c won't run off garage power. Here is the setup and the problem -- I attach our 30 amp cord to a heavy construction grade extension cord (not a little thin cord), using an adapter. The two cords total about 40 feet in length. The extension cord plugs into a wall socket in the garage.

The a/c starts ok, and runs for a minute or so, quits, starts again, and quits.

Is this because of the length of the cords? Would an even heavier extension cord help? Is this due to some limitation on our wall socket? I run woodworking equipment on the same socket, with no problems. And the circuit breaker does not trip.

Thanks in advance for your advice. (Yes, I know I should know much more about electrical power than I do, but I don't. So please forgive my pathetic ignorance.)
  • Mmwtdh wrote:
    Shorter cord would help and larger gauge cord would help. You're running out of juice due to resistance loss.

    that and if you're plugging into a standard 20-amp wall socket it's likely that the amp-pull from the AC's compressor combined with whatever else is running is tripping the circuit. can you disable anything else like the battery charger side of the converter, inverter, res. fridge, etc. (if so equipped)?
  • You are going to burn up your a/c doing that. Your house outlet is either 15 amp or 20 amp no matter what size extension cord you use. Not enough to start and keep running the a/c. You'd have to have a 30 amp breaker installed in your service box and wire that to a 30 amp outlet.
  • Shorter cord would help and larger gauge cord would help. You're running out of juice due to resistance loss.