Roof Air(s) not working

[Dean Johnson]

Hello All,
Just an observation here.
My Monterey has been sitting now for a few months and we are getting ready for a trip south to dry out a bit so I tried the roof air conditioners and heat pump function with the generator running and nothing comes on!? As I cycle through the different functions on the thermostat, I can hear the generator change tone like it is taking a load but I get no power to the units or they don't come on at all.

The Xantrex and Aladdin both show 120volts with the generator running and the breakers are not tripped.

Then I go back out to try again and having forgot to turn the thermostat off, the A/C was on!??

Has anyone experienced this, do they just need to 'warm up' a bit before they kick on>?

Thanks,

Dean Johnson
2005 Monterey 4 Slide
Cat C-9

[Edward Buker]

Dean,

There are some delays built into the start up of the compressors. The intent is to let the low side and high side pressure equalize so that the compressor is not starting against a high pressure. I think when the system is shut down and left unpowered it invokes the delay given it does not know how long the compressor has been off, like if you got a short loss of 120V power. If the air units do not start after several minutes then it would be time to start looking at why. In addition there is about a minute delay built into the transfer switch once the generator starts to let it stabilize, once that has transferred the power then the air unit delay may start with its timer or it may just need 12V and use that power source for the timer circuit. In summary some delay is normal....

Later Ed

[Dean Johnson]

Thanks Ed,
I know about the delay in the transfer switch when the generator is turned on so I waited until it showed full power on the Aladdin. I just tried the rear unit, left the switch on with the generator running for about 20+ minutes and it never came on so I don;t know what's going on with that one. I guess I'll have to have it looked at.

Thanks,

Dean

[Edward Buker]

Dean,

You may be able to rule out the thermostats by switching them if you have two. Sometimes the 120V breaker will trip but the handle will be in the on position so you might try flipping it off and back on. Depending on how deep you want to go into this you can check for 120V at the air conditioner. If it is not the thermostat or the 120V supply then the next candidate that I would try is the starting capacitor which typically is pretty easy to change out. If these three things do not get the unit started then I would have it looked at.

Later Ed

[Dennis Crawford]

Dean,

The AC units on my 2005 have a built in delay.  The front air has a much longer delay that the rear.  My guess is the front delay is 4 to 5 minutes.

Dennis

[John Harris]

We have a different problem with our AC... After the rear AC/Bedroom unit has run for a period of time, when we move the thermostat to shut it off, it will not stop running. We need to turn off the circuit breaker to get it to stop running...