A/C randomly shuts off

[DirtyMax88]

good morning everyone. Last trip of the year, we are in Savannah GA. Its humid and rainy. Checked in yesterday plugged in, turned everything on, running normal. This morning, one of our a/c's just turned off, both the compressor and fan (it has happened twice in about 4 hrs). We did not lose power. Both legs read normal, 118-121 on PMS display and at the pedestal on our surge protector. The thermostat still reads cool, and fan has stayed on hi. I was told to run fan on hi while in humid temps to help prevent freezing, which is what we do. If I turn the thermostat off and let it still for a while, then turn it back on, everything works normal. Do you think the unit is freezing up or is it a connection issue somewhere, maybe moisture somewhere because of all the rain and himid weather. Thanks in advance!

 

[danemayer]

Hi Will,

If your Newport has the PCS Energy Management System, and it was the rear A/C that shut it's compressor off, it may be a power limitation. The PCS system sheds power to selected devices in a programmed order to ensure you don't pull more than the available power.

 

[DirtyMax88]

Hi Will,

If your Newport has the PCS Energy Management System, and it was the rear A/C that shut it's compressor off, it may be a power limitation. The PCS system sheds power to selected devices in a programmed order to ensure you don't pull more than the available power.

Hey Dan,
Thanks for the quick response. We do have the Energy Management System and it was the rear A/C. We didn't have anything else running on that leg #1. The bedroom a/c, water heater and satellite are on leg #2. Those are the only 4 items we had on (well 3 when the rear a/c shut off). Would it still shed loads if this were the case? Could there be an issue with the Dometic CCC2 Thermostat? Do they just go bad or malfunction?

 

[danemayer]

It could be freezing up and thawing causing intermitten behavior. I doubt it's the thermostat. Could be a loose wire on the PCS relay behind the cover of the main circuit breaker panel.

The PCS when shedding power to an A/C unit, simulates a freeze condition on the A/C. You might cycle through the PCS display screens to see if it recorded shutting of the REAR A/C unit.

We have several PCS manuals here that may be helpful.

 

[jmarnell]

We had a similar problem with one of our A/C units shutting down randomly and not restarting. I would shut the system down at the thermostat, let it sit for for a few minutes, then it would start again. Our mobile RV repair guy finally traced the problem to a bad relay in the A/C's control box. He replaced the control box and we haven't had any trouble since.

 

[DirtyMax88]

We had a similar problem with one of our A/C units shutting down randomly and not restarting. I would shut the system down at the thermostat, let it sit for for a few minutes, then it would start again. Our mobile RV repair guy finally traced the problem to a bad relay in the A/C's control box. He replaced the control box and we haven't had any trouble since.

Thank you! I'll keep this in mind too! Weird that is hasn't done since the middle of the day now.....

- - - Updated - - -

It could be freezing up and thawing causing intermitten behavior. I doubt it's the thermostat. Could be a loose wire on the PCS relay behind the cover of the main circuit breaker panel.

The PCS when shedding power to an A/C unit, simulates a freeze condition on the A/C. You might cycle through the PCS display screens to see if it recorded shutting of the REAR A/C unit.

We have several PCS manuals here that may be helpful.

Thank you Dan. Ill look into this as well.