Originally Posted by Squid
In the past on my trailer pulls I was always told never run the AC on the house 110 volts. Was going thru Eds AXIS user guide and manual and the impression I got was it was ok. I always thought it would burn up the compressor because you needed 30 amp...
If your AC needed 30 Amps to run, then all motorhomes with 30-Amp service would not be able to run anything else when AC was running, right? And clearly that's not the case.
A 15-Amp circuit is cutting it close under some conditions, which is why I prefer plugging into a 20-Amp circuit when available. For example, a 15,000 BTU/hour AC which is not high efficiency can pull close to 15 Amps on a hot day, particularly when RV is also warm inside. On the other hand a high-efficiency 13,500 BTU/hr AC should pull well below 15-Amps.
What you never want to do in my opinion is use a long extension cord that is not rated for the high current an AC will pull. This will result in voltage drop in extension cord, which means voltage at AC will be lower. And the lower voltage at AC means it will pull more current, which then causes more voltage drop in extension cord, etc. If a breaker doesn't trip first you may very well damage an AC compressor under these conditions.
When practical, I use the 30-Amp RV extension cord and then use an adaptor right at the receptacle. This way I minimize chance of overheating motor due to low voltage.