boogie_4wheel wrote:

I'm going to disagree with everyone... It isn't that the cord was too small, there was a loose connection AT THE PLUG. The loose connection resulted in arcing, heat from the arcing melted the molded plug end. The cord could have been 1/0 and the plug would have still melted. A 15A plug is rated at 15A constant load, just like the 15A breaker that was feeding the outlet that the cord was plugged in to. There wasn't an overload condition, just a loose connection.

I do agree with having heavier extension cords. A 12ga cord is good, a 10ga is great. As load increases over a run, the resistance in the wire (even small resistance) will cause the voltage to drop. The size of cord, wire gauge, depends on the load and length of the cord. With nothing else running in the trailer, you could run most AC units on a 50ft 12ga cord without too much voltage loss, with the assumption that you don't have low house voltage to begin with.

dodge guy wrote:

Don`t just get a big cord! get one that is rated at 20amps which would be 12ga. wire. some cords just have a very thick covering that makes them look HD but are really still a 15 amp cord. and as far as the house outlet goes 15 amps is the max that can be put through it, I`m assuming it is a 15 amp circuit. so turn on nothing else when running the A/C!

RoyB wrote:

I lucked out and found some contractor grade real heavy duty 10 GAUGE (10-3) extension cords at a yard sale. These are not going to be cheap at the stores...

It is must have item however... One of my trailers is about 60-feet away from my garage connections and I use an 30AMP RV extension cord on the end of the 30AMP shore power cable and then connect to my 10-GAUGE extension cord going to the garage.

Also I could not get away with using the small round type RV30A-15A adapters. I had to get one of those 18-inch long "dogbone" type adapters. WALMART sells one in their RV parts section. The little round and triangle type black adapters always got hot on me after being run for a short time. Hook everything up and get you air conditioner going then go feel your connections everywhere after awhile and make sure nothing gets warm to hot on you. This can damage your air conditioner as well as when something gets hot it will drop your operating voltage feeding the trailer. I have an RV 120VAC plug-in meter in my trailer where I can see it in plain view so I get to observe the power reading easily. This meter has a GREEN scale marked on it which is the SAFE ZONE to be used when the air conditioner is running. Good to have around...

Use this type adapter...


DO NOT USE these type adapters...


this is the RV meter I use to monitor 120VAC line voltage with inside trailer. Don't use air conditioner if the reading is outside the green "SAFE ZONE" reading.


Been doing this for five years running my OFF-ROAD POPUP trailer and a Fifth Wheel trailer off separate 20AMP Garage 120VAC receptacles without any issues. I can run everything in the trailer including air conditioning but have to watch what is being turned on at the the same time. i.e. if I turn on the Microwave Unit when running the air conditioner it will trip my garage breaker. The main thing that is running in both my trailers in the converter/charger keeping the battery banks up and running and during the winter months I run a oil-filled electric heater set on low to keep things from freezing inside the trailer.

Its also kinda neat to have a quiet place to watch NASCAR and the grandkids love sleeping-over nights in the trailers. we do as well haha...