AC not cooling in 115 degree heat

I'd like to hear about the genset shutdown, and the Make/Model of the A/C.

We have daughters in CA and NM. CA has reported 112*, hate to think of NM..

In the years that I have been an RV Net member, I don't recall ever reading about A/C's shutting down due to heat issues. huh...I am sooo glad that I am not in Needles or Barstow or the Mojave right now.


Gary Haupt

Spend the day at the library, museum, movies, etc. Return to the Rv after the sun is setting.

We're in a campground in FL right now. Temp and humiditiy both in the upper 90s. I mention humidity because our A/C has to remove moisture as well as heat to provide comfort inside the coach. You said "generator quit" and "breaker" and "didn't cool." So I wonder, did you switch from Driving with GenSet running to Parked and Shore Power? Driving, your Heat Loss passing through that hot air could easily overcome two A/C units. If you're on Shore Power now, at a campground, chances are you have low voltage as well as high heat. Today, voltage in our coach was 107. The so-called "110" is more like 120, even 122 on a good day, so 107 is seriously low. If you have that, it'll decrease A/C performance AND raise its current demand in Amps. Our breaker panel was HOT today and the A/C (a 15000 Coleman) tripped its dedicated 20A breaker. I set up a fan to cool the breakers.
If your A/C is a few years old, I suggest Chris Bryant's A/C Tune-Up. It'll give you better cooling AND less amp draw.

As has been mentioned if your discharge air is 20 degrees cooler than the room temp your AC is working. If your AC is working then you need to close off the upper bunk and everything else you can close off. Check and clean your filters.
If you have a 30 amp service you probably can not run ANYTHING but the two AC units,
If parked use a windshield cover and close the cab area off from the rest of the RV If possible keep the front of the RV facing the sun or if you have an awning have it extended and the sun on that side. We have had the generator shut off while parked in high temps and it was due to overheating. When parked open the generator door and leave it open and try to keep it in the shade.
All of our windows are tinted the overhead window has solid insulation against the glass. We also try not to drive from 1PM to 7PM

downtheroad wrote:
We have found that in really hot conditions...105 and up, we can expect to get about 25 degrees out of our trailer air conditioner.

This has been our experience in 3 different trailers.

You're spot on- doing a bit better than average, actually. Ambient air temps are key with RV A/C since they function much like heat pumps, except that they're "cooling" pumps.
Here quoting from RV air conditioners

The factory specification is approximately 20°F cooler air exiting out the discharge than the ambient room temperature entering into the filter. Air conditioners only remove the heat from the air, so if your RV temperature inside is 90 degrees the discharge temperature would only be approximately 70 degrees.

115 is just way higher than the system was designed for. You need more cooling power for that kind of heat. A second (or even third) AC is a must in any size rig under those conditions.
I know what you mean regarding the PNW. Today is the first time in two years we've turned our AC on.

We have found that in really hot conditions...105 and up, we can expect to get about 25 degrees out of our trailer air conditioner.

This has been our experience in 3 different trailers.