Forum Discussion

travelrn2013's avatar
travelrn2013
Explorer
Apr 26, 2014

A/C can only run by itself, anything else trips it

We are now in Southern Texas and it's already a 100 degrees. Fifth wheel 33 ft with one middle a/c unit and 30 amp. I am packed in shade. It's not keeping very cool except in middle near it though cool air is coming out and it runs almost non-stop. If water heater kicks on it trips it, coffee pot trips it, microwave of course trips it. I am wondering if I can put another a/c unit in or should I replace the unit that's there? Can I add solar panels to help with the constantly tripping of the breakers? Should I convert to a 50 amp system? I don't know where to begin and it's still Spring so I am sure the temps are going to get warmer. Any suggestions besides leaving since I'm on the job for a few more months?

28 Replies

Show More
  • Larryect's avatar
    Larryect
    Explorer
    Apr 26, 2014
    Good advice so far. What size AC?

    Check Voltage with AC running. I suspect it is your 30 amp main tripping in the trailer. Put the water heater (at least) to propane. Breaker could be weak.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Apr 26, 2014
    "Just the breaker to the A/C flips in the panel and shuts off all electric in rv."

    :S
    Just A/C breaker tripping would not shut down all electric in rv.
    Rest of rv 110V electric should be on other circuit breakers.

    That sounds more like the RV Main breaker tripping.
    Overloading.....or weak breaker

    Simple plug in AC Voltage monitor will help you check voltage



  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Apr 26, 2014
    Just the breaker to the A/C flips in the panel and shuts off all electric in rv
    The AC should be on a dedicated breaker but it seems you have additional loads on that breaker.

    A simple plug in digital voltmeter inside the rig would be a good step to determining the voltage. If the pedestal has both 20A and 30A plugs then most likely the 20A plug voltage will be the same as the 30A plug.

    A 30A plug should run one AC and other loads like a coffee pot, but add refer, charger and maybe not.

    First step: What is your voltage?
    Second step: What does the AC nameplate show for amps?
  • time2roll's avatar
    time2roll
    Nomad
    Apr 26, 2014
    If your air conditioner is tripping the branch 20 amp breaker then it could be low voltage but I speculate the compressor is getting to end of life. How old is it?

    The campground maintenance guy might have a voltmeter and the basic know-how to get a reading.
  • 2oldman's avatar
    2oldman
    Explorer II
    Apr 26, 2014
    travelrn2013 wrote:
    I don't know how to check the voltage at the box where we hook up?.
    Don't check the box, check your Rv. It's not hard. Every RVer should carry a voltmeter (assuming you do not). IMHO this is the most likely cause of your problem, and if it is, taking it to a shop is a big waste of time and money, and won't solve it.

    Get a voltmeter. When running the air, check the voltage at any of your ac outlets. Also check when NOT running any big load. If this is out of your comfort zone, find someone to do it for you. Report back.

    Are you in a park with many other RVs running air? Does this happen in other parks?
  • travelrn2013's avatar
    travelrn2013
    Explorer
    Apr 26, 2014
    Just the breaker to the A/C flips in the panel and shuts off all electric in rv. I turn off the a/c and only have to flip the breaker to the a/c back and then everything powers up. I don't know how to check the voltage at the box where we hook up? So changing to a 50 amp system will not increase the load I can draw? ******how do you find a trust worthy repair place. Place in Corpus wanted to keep my rig for over a week. I am not wanting to leave it anywhere.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Apr 26, 2014
    Which breaker is tripping:
    The A/C Unit circuit breaker?
    The RV's Main 30A breaker?
    Or the power pedestal 30A breaker?

    Bad breaker.....
    Overloading circuit....
    Low AC voltage....do you know what the incoming voltage is?

    Run fridge on propane, run water heater on propane

    Solar will only help you charge battery.

    One A/C unit in 100*F PLUS temps....tough to keep 33' rig cool
    Heavy load on A/C unit..especially if it's just a 13,500btu unit.
  • 2oldman's avatar
    2oldman
    Explorer II
    Apr 26, 2014
    Sounds like a low voltage issue. When voltage sags, amperage increases and can trip breakers and worse, damage your a/c over time.

    Are you in a park with many other rigs running a/c? That's a common cause. Check your voltage when running the a/c.. if possible. If it's below 112 I'd find another park.

    Solar panels are not going to help.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,343 PostsLatest Activity: Dec 13, 2025