My ac unit could have burned up our Lexington

[Luke Moseley]

On 7/1/21 we departed on a trip from Virginia to Florida. The 1st night we stopped I noticed an electrical type odor when the ac was running. I investigated by pulling the filter cover off, sniffing around and looking for signs of trouble, nothing. I went on the roof, removed the ac cover and checked for obvious signs of problems, nothing. Since it was hot and humid I kept running the ac. On night 3 of the trip we were set up and the ac was running fine, then we started smelling that electrical smell followed by a loud bang. No more ac. What I discovered, upon another inspection, is that the wires in the junction box behind the filter were melted, the breaker never tripped. I can't tell if a short happened in that junction box but, those wires were burned. This is a Dometic 13,500 btu ac/heat pump. 4 weeks ago I had a microair soft start installed so I could run this ac on a 20 amp service when necessary. It worked fine for a month but who knows. Helpful comments appreciated. Thanks, Luke.

[SeaDog]

For some reason you were drawing high amperage if the wires burned, might have been caused by low voltage loose connections or an AC compressor going south. I think I would ring out the AC compressor to see if it is shorted. Keep in mind when plugged into 20 amps there is not much extra voltage/amperage available for the heavy use appliances like the AC.

[TitanMike]

Originally Posted by Luke Moseley

On 7/1/21 we departed on a trip from Virginia to Florida. The 1st night we stopped I noticed an electrical type odor when the ac was running. I investigated by pulling the filter cover off, sniffing around and looking for signs of trouble, nothing. I went on the roof, removed the ac cover and checked for obvious signs of problems, nothing. Since it was hot and humid I kept running the ac. On night 3 of the trip we were set up and the ac was running fine, then we started smelling that electrical smell followed by a loud bang. No more ac. What I discovered, upon another inspection, is that the wires in the junction box behind the filter were melted, the breaker never tripped. I can't tell if a short happened in that junction box but, those wires were burned. This is a Dometic 13,500 btu ac/heat pump. 4 weeks ago I had a microair soft start installed so I could run this ac on a 20 amp service when necessary. It worked fine for a month but who knows. Helpful comments appreciated. Thanks, Luke.

If the unit had been operating properly for some time, then the Micro Aire unit was installed followed by failure in 4 weeks, that would be the first place I'd look. Improper installation or wires left loose would be my suspicion.