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Author Topic: A/C unit issues  (Read 321 times)


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A/C unit issues
« on: July 26, 2017, 09:43:43 AM »
Hi, I'm a newbie here. not sure this is the right spot for this. but here goes.

So I'm living in my 29' Fleetwood Terry trailer while I build my house. I was running on a Generator for a few months while I waited for the power company to hook up my lot. It hadn't been hot enough to run the A/C but one day the Gen was acting up and was getting an over voltage warning and shutting down. it's only a 2000 watt Honda gen. I didn't thing I would be running on a Gen this long. so after some searching I shut off the A/C breaker and everything was fine. I just had my 30 amp breaker with RV plug and tried to run the A/C. it worked for a few minutes then tripped the breaker. what I did notice is that now when the breaker is closed the A/C unit turns on even when the thermostat switch is in the off position. I ran the furnace all winter with out any issues and now this has started happening. I'm stumped as to what the issue might be and where to look. Does anyone here have any ideas of what might be the issue? what I can replace? Thanks in advance for any help.


Gary RV_Wizard

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Re: A/C unit issues
« Reply #1 on: July 26, 2017, 10:39:37 AM »
Hard to say without further testing and measurement.  Over-voltage is usually a regulator problem in the genset, not excessive load. Are you sure the code was specifically "over voltage" and not just "overload"? Those are quite different.

The Honda 2000 simply lacks enough power to get an a/c through its compressor start-up cycle, so it is likely the genset overloads almost every time the a/c compressor kicks in. It's sustained power output is just 1600 watts and your a/c is probably 1300-1400 watts continuous and 2x-3x that for a couple seconds every time the compressor starts.

As for the a/c turning on without the thermostat in the ON position, that could be either the thermostat (not really Off) or the control circuit board in the a/c.
« Last Edit: July 26, 2017, 10:42:23 AM by Gary RV_Wizard »
Gary Brinck
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Home: Ocala National Forest, FL


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Re: A/C unit issues
« Reply #2 on: July 26, 2017, 05:14:30 PM »
I knew the Gen wasn't enough to run the A/C. that's why I was surprise when the A/C unit mysteriously turned on when it was not switched on. I had no intentions on ever running the A/C with that Gen. it's just a stop gap till we had actual power hooked up on the lot we are building and living on. It was in fact an overload alarm that was triggered on the Gen. this happened when I was a way at work and my wife was dealing with it the first time it happened.

as for the A/C unit. if it was the thermostat not really off, do you mean accidentally switched on? because it has never moved to the Cool side. it's always either been off or on heat. is it possible that the thermostat is hosed and needs to be replaced? or should I bee looking closer at the control circuit board in the A/C unit it's self?

John From Detroit

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Re: A/C unit issues
« Reply #3 on: July 26, 2017, 05:34:59 PM »
Generally a Honda 2,000 is very boarderline if able at all to run an A/C.. Air conditioners take more power if A: It is hotter out or B: The condenser is clogged with "Stuff" (Cotton wood cotton for example)   In fact my A/C's will trip a 20 amp breaker (The branch breaker for the A/C) if the condenser needs cleaning even with good power.

So step one is clean the condenser
Step 2... If that honda is an inverter generator.. Get it a companion.
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Re: A/C unit issues
« Reply #4 on: July 28, 2017, 10:54:04 AM »
Ok step one. I wasn't using the Honda Gen to run the AC. as I mentioned. for some reason the ac unit is turning on when it's not switched on.

step two. I have an RV plug installed with a 30amp breaker. I'm now running my trailer off the Hydro grid not the Gen.

I'm trying to trouble shoot why the unit turned on when it was clearly never switched on. and now I can not turn it off. when I reset the breaker it runs for a few minutes then trips the breaker. absolutely nothing to do with the Honda Gen.


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Re: A/C unit issues
« Reply #5 on: July 28, 2017, 02:50:52 PM »
I have seen contactor points on residential units "welded" together, Troy.  Unusual, but it can happen......usually on older units with lots and lots of cycles.  It was more common on units where the contactor only broke one side of the 240v (single phase) line; ie, the contactor just had one set of "points".  If your contactor/relay looks OK though one would sure have to look hard at the stat or the stat wiring.  Then the breaker tripping..... 2 problems at once?  Ouch!

The results of your troubleshooting will make v-e-r-y interesting reading.  Hope you post back. 
Ed Sievers/Denver, CO
07 WGO Outlook 31C
Toad: 16 Soul with 6spd DIY
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