Amps to run AC in travel trailer

Discussion in 'General Electronics Chat' started by Sister on the Fly, Aug 14, 2009.

  1. Sister on the Fly

    Thread Starter New Member

    Aug 13, 2009
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    This may not be the correct place for my concerns, but as a newbie to this forum, I'm lucky to get this far. I need to know how to increase the amps so that my AC will run in my travel trailer. It is plugged in at the pole (110v) from which I have a 25 foot extension cord to the trailer. The AC compressor comes on, but then almost immediately goes off. Can anyone help or direct me to the proper forum?
     
  2. gerty

    AAC Fanatic!

    Aug 30, 2007
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    We need more information.
    How big is the a/c, (how much current does it draw)
    What guage is your extension cord.
    What else is on the same circuit.(are there 10 more trailers plugged in)
    Is there something else in your trailer plugged in.
    Was the ac working when it was installed.
    Answering this'll help us to help you.
     
  3. Sister on the Fly

    Thread Starter New Member

    Aug 13, 2009
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    The power cord is designed for a travel trailer, bought at an RV supply. There is only one trailer on it. It is a 25-foot 2008 Airstream that is in good working order. The only other appliance using the power source is the refrigerator in the TT. The AC is 13,500. The electrical sysem requires 30 amps.
     
  4. someonesdad

    Senior Member

    Jul 7, 2009
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    When you say "it goes off", do you mean the air conditioner quits running or a circuit breaker blows?

    Without knowing more, my guess would be that you could have a low voltage condition at the air conditioner. This is pretty easy to troubleshoot, but you need some measurement equipment and some knowledge. If you're willing to learn some basic AC electrical stuff, it's something you could do yourself. If not, it would be best to hire an electrician.

    The first step is to determine whether the problem is in the trailer or in the electrical supply you're connecting to. One way to do that is to plug the trailer into a known good AC power source.
     
  5. Sister on the Fly

    Thread Starter New Member

    Aug 13, 2009
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    The compressor kicks off, but the fan doesn't. I don't own a volt meter so I'm not prepared to learn anything until I buy or borrow one. I would be surprised if the problem is with the AC since it is so new and it worked perfectly on my last trip out last month; but I realize that one can't predict when an appliance will fail.
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    Low voltage will cause the compressor to pull more current and get hot. It has a thermal breaker that opens when that happens.

    I am thinking that if your reefer still runs ok, low voltage may not be the problem. It has a thermally protected compressor as well. If the reefer keeps running, it may be that the AC compressor has gone sour. If the AC has a warranty, it is really worth taking it back to the dealer for a check and replacement.
     
  7. gerty

    AAC Fanatic!

    Aug 30, 2007
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    When you say the electrical system requires 30 amps, are you sure that's at 120 volts, and not 220 volts? The ac alone should draw about 20 and the refer I'm guessing 4-7 amps. At 120 volts that would be right at the limit of a 30 amp 120v circuit, and we haven't included all the lights tv etc...
     
  8. Heavydoody

    Active Member

    Jul 31, 2009
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    If it has low refrigerant it would immediately go into low pressure and shut down since a roof air doesn't hold much to begin with. And being new doesn't necessarily mean anything; I have seen high end chassis delivered from the manufacturer with no refrigerant charge in them.

    Having said that, I do think it is your power supply. Not certain about roof airs, but Cruiseair units will shut down due to low voltage while everything else in the coach continues to function. I think the best recommendation was to find a known good power source, and the best place to do that would be at a dealer since I would assume the unit is still in warranty. I bet they would be happy to assist you.
     
  9. gerty

    AAC Fanatic!

    Aug 30, 2007
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    Probably the easiest/cheapest thing to do is try another outlet, turn of all other appliances first.
     
  10. Sister on the Fly

    Thread Starter New Member

    Aug 13, 2009
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    Thank you, gentlemen, for all your thoughts and suggestions. I have now purchased a volt meter, so everybody in the neighborhood better watch out! I'll do some testing and see what I come up with and maybe get back with you for more answers.
     
  11. Justpassinthru

    New Member

    Aug 13, 2009
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    I assume you're using an adapter to go from your 30A male to a standard 15A Edison plug into a house circuit.

    Like stated above it sounds like a low voltage situation. You'll have to add a 30A@110V circuit and breaker to your house panel to properly feed enough power to your TT. DO NOT ATTEMPT TO USE a dryer or stove receptical as these are usually wired for 220V and your TT is wired for single phase 110V.
     
  12. BillB3857

    Senior Member

    Feb 28, 2009
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    Most RV refrigerators are not compressor operated units. They use absorption technology with propane or electric heat to accomplish the cooling.
     
  13. someonesdad

    Senior Member

    Jul 7, 2009
    1,585
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    For folks that aren't familiar with trailers in the US, a common hook-ups in an RV park is a 120 VAC 30 A service. Larger RVs can hook up to 50 A services, which are also sometimes supplied. When plugging into a standard 120 VAC 20 A house circuit, one uses an adapter on the RV's power plug (may look similar to this). Personally, I use a 15 A plug instead of the 20 A because 15 A outlets tend to be more common and/or you can connect to another extension cord if needed.

    In the trailer, the air conditioner is on its own 20 A circuit breaker. There's a 30 A main breaker. There are a number of other circuits, depending on the trailer.

    There's a power supply to convert 120 VAC to 12 VDC to charge the batteries, run the lights, the heater's fan, and perhaps some other things. The refrigerator runs on either 120 VAC power or propane.
     
  14. loosewire

    AAC Fanatic!

    Apr 25, 2008
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    How about those texas fire ants and camping with pets.
     
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