Roof A/C compressor running constantly

[scottydl]

My trailer's HVAC thermostat seems to have lost some functionality, specifically the temperature slider. It's the original Dometic Duo-Therm model, which is lacking anyway. I discovered yesterday that no matter where I set the temperature when the A/C is set to "Auto", the compressor is running and blowing cold... regardless of how cold it gets in the trailer. I don't really mind that for now (until I replace the thermostat with something more modern), but my only concern is the compressor and fan running for ~8 hours solid if the A/C is turned on overnight. Is there any issue with that, or are these units made to run constantly if needed? Normally it would kick on and off every 10-15 minutes as needed, with similar breaks in between cycles.

 

[Lou Schneider]

No problem running the A/C continuously, anyone in the desert southwest right now is doing just that for 12 hours or more each day.  The only issue is if the evaporator gets cold enough to ice up you'll be without airflow until it thaws out.

 

[scottydl]

That helps, thanks. Good news is that I'm in Michigan this trip. Temps in the high 80s low 90s this weekend, but we've got a shady site so it's pretty comfortable anyway.

 

[Larry N.]

When I was at Oshkosh a few years back, with no hookups, I ran the A/C for something over 72 hours straight while we were on site, not counting on the road getting there and leaving -- probably more than 24 additional hours -- 'cause it was hot and humid, typical summer in Wisconsin, as far as I know. There were no adverse effects. So as Lou says, it's not a problem.

 

[scottydl]

I've popped the breaker a couple times this weekend (on the campground power supply) while the A/C's been running, but I'm wondering if that is due to dips in the campground current supply. The park has been packed and lots of power demand I assume.

 

[Lou Schneider]

High demand will drop the campground voltage and cause the a/c to draw more current.  Voltage x Current = Power and if one goes low the other has to increase to develop the power needed to turn the compressor.

An inexpensive plug-in voltmeter (one of the functions on the $30 Kill-A-Watt, BTW) will let you monitor the incoming voltage and take appropriate steps if it gets down into the danger zone where you risk damage to the motors.