AC afraid of the heat?

[The Incorrigible Dirigible]

Any thoughts on what would cause our air conditioner to work when the generator is running, but refuse to kick on when we're connected to shore power? The AC unit in question is not quite two years old.

The coach's second AC unit is just over a year old and has stopped working entirely. It powers up, but will not actually turn on and blow air, warm or cold. No circuit breakers are blown...I am stumped. And very hot. Could this be a cascading failure, or does it sound like two separate problems?

The thermostat was replaced in mid-2009 as well. All was in working order a couple of months ago.

Any thoughts or advice are much appreciated!

[sgtjoe]

Is your RV 30 or 50AMP??

[The Incorrigible Dirigible]

30-amp, currently stepped-down to a 220v household plug as we are with relatives. The AC has not had trouble running on even 110v in the past, however. Could there be some additional internal power draw preventing it from waking up?

[RV Mech Tech]

You have 220 Volts going into the coach?????

[The Incorrigible Dirigible]

I wasn't aware that was a problem. We have plugged into household circuits without issues before; the garage where we're at has a 220v (3-prong dryer-style--perhaps my calling it 220 is incorrect?) plug available, and we're using a 30A surge protector between the coach and the house. Should I stick to the 110v?

[Richard S.]

Your coach is wired and set up for 110 volts AC, 220 volts AC will burn things up. Also when when pluged in to shore power if you don't have 30 amps you can burn up the air conditioner with to low of power. ( brown out )

[The Incorrigible Dirigible]

Good to know, thanks Richard. Switching to a 110v plug immediately. That said, the air conditioner has run without problems on 110 in the past, but is not running now. Is the use of 110v a possible cause?

[Richard S.]

This info below may give you a better understanding.

RV Electric

[The Incorrigible Dirigible]

Originally Posted by Richard S.

This info below may give you a better understanding.

RV Electric

Good background, thanks. Am very glad to have gotten away with not frying anything!

[sgtjoe]

Since your Coach is a 30 AMP, you may not be able to run both AC on shore power but can on generator if it is big enough. In your Coach there should be a switch that allows you to select which ac you want to run and it should also have a selection for both when running off the genny. That may be the problem, also you may have damaged the one ac being on 220. See if you can locate the selector switch for which ac you want to run. I could be wrong on this for a National, but that is the way my Georgetown gasser ac's were set up. Hope you didn't damage anything.

[The Incorrigible Dirigible]

The problem I'm having is that NEITHER AC will run on shore power. We have to run the gennie to get them both to run, at any time. My concern is that neither one will kick in when we are hooked up to shore power.

Our National's got a selector switch similar to the one you describe; it works to turn on the rear AC when the genset is running, but we get no response when plugged in to shore power at all. I assume the (rear) unit is not damaged, because it will run with the generator. The front unit doesn't respond at all other than to power up, so I'm not sure what its issue could be.

Originally Posted by sgtjoe

Since your Coach is a 30 AMP, you may not be able to run both AC on shore power but can on generator if it is big enough. In your Coach there should be a switch that allows you to select which ac you want to run and it should also have a selection for both when running off the genny. That may be the problem, also you may have damaged the one ac being on 220. See if you can locate the selector switch for which ac you want to run. I could be wrong on this for a National, but that is the way my Georgetown gasser ac's were set up. Hope you didn't damage anything.

[RV Mech Tech]

I D - on almost every big class A that has a generator you will have an automatic transfer switch to switch from generator power to shoreline- when you connect a 220 volt power source you more than likely will damage whatever appliance you try to operate with this 220 going into the coach and that 220 volts has to go through the transfer switch first so there is a possibility that it has been damaged - when you reconnect to 110 try every other appliance as well and see if anything else is damaged - if nothing else will operate on 110 check the transfer switch first- going by your description it sounds like something on the control side of your front AC has been damaged and you will have to get up on the roof and remove the cover and check the control board and other parts as well- when something like this happens and something stops working you take nothing for granted and check everything over -I have seen AC units damaged, wires burnt etc. and still operate -(maybe not up to full capacity but they will just run) -so check everything over that operates on AC 110 volts- this does happen quite a lot where someone connects their RV to a house dryer outlet- an RV outlet only has one 110 volt leg to power your shoreline cord - you can use a house outlet if one of the two 110 v legs are not used but a dedicated line from the electrical panel straight to the RV plug outlet is better and safer as shown in the 'RV Electric' link mentioned by Richard S- check that transfer switch first and let us know what you find!

[The Incorrigible Dirigible]

All other 110v appliances seem to be working--microwave, fridge on electric only, etc.

Ours is an older coach--rather than a switch to transfer from shore power to generator, you have to plug the 30A plug directly into the generator panel.

Big thunderstorm today. Will climb up to check AC control panels tomorrow.

Thanks so much for the assistance & expertise! Will return with updates.

[Vegasdan]

A 110v house circuit is only 15amps. I would not even try to run one A/C on it. Maybe it can be done.?