roof A/C TRIPS 20 AMP BREAKER

Britches wrote:
thank you all for your info. The power cord is 25ft. plugged into 30amp at rv park
this trailer in 30amp. I cleaned the filters and gently the fins checked the wiring and connections. I turn on the a/c and it takes right off and blows cold air for 15 min. then trips the inside breaker 20amp that is a/c only. I will go test the volts to see if they are 109 or better by the way the main is 30/15 is this adequate

Hi,

It is common for people in parks with only 30 amp power connections on the post to complain about low voltage, and this caused high motor amperage on the A/C unit, especially when 'everyone' in the park is running the A/C units. This caused the power at the distribution panels to drop to un-acceptable low voltage, and then your unit has only 105V or less to work with.

You can get a 'kill-a-watt' at Amazon.com

You can leave that type of meter plugged into a receptacle, (I keep one in my kitchen receptacle) and monitor voltage. If it is running 115 - 120, I basically ignore it most of the trip. But on a hot day, if it dips below 110 volts, I will keep a close eye on it, and shut off my A/C if below 105 volts. Actually at 110 volts, I will plug in my 12 voltage booster.

If you happen to have a 50 to 30 amp adapter, check to see if you can use that, and plug into the 50 amp circuit breaker. Normally the campground 50 amp receptacle is in much better shape, and less voltage drop across it.

Also check the 30 amp plug, and see if it is warm. If the campground plug is worn out, or has been overheated in the past, the brass inside the plug will not hold onto your trailer RV power cord tightly, and can cause a voltage drop there, as well as overheat the plug on the trailer wiring. So if it feels really warm, or hot like a coffee cup, stop using your A/C unit. Ask for another site (that will probably also have a worn out plug) and ask them to replace that receptacle before it catches fire.

If you have a 20 amp to 30 amp adapter, you might be able to use that - but will only be able to run the A/C and perhaps something with a really small load, such as the TV set or laptop charger.

Also regardless of everything else, change the refrigerator to gas on warm days. It will take 3 amps off the electric cord loads, and also provide 40% more cooling capacity than running on electric.

And if you have a electric element on your water heater, shut that off too, you will have better voltage as a result.

Have fun camping!

Fred.