Slow running Coleman A/C

[wynot]

We were camping in NC this week when all of a sudden, our Coleman Mach A/C drops to a very slow running speed.  Seems to only be related to the fan, as the A/C is putting out cold air and the heat strip still puts out heat.  Changing the control makes it run slightly faster on high, slower on low.
 
Filters are clean and nothing is in the fan, and it freewheels quite easily.
 
This happened in an instant, from max cool, high fan speed to slow.  There was no sudden power bump or brownout, and we were in the camper when it happened.
 
Anyone else run into this?  I'm also at a loss on who to take it to to look at it - an RV dealer or an A/C guy...

[wavery]

We were camping in NC this week when all of a sudden, our Coleman Mach A/C drops to a very slow running speed.  Seems to only be related to the fan, as the A/C is putting out cold air and the heat strip still puts out heat.  Changing the control makes it run slightly faster on high, slower on low.
 
Filters are clean and nothing is in the fan, and it freewheels quite easily.
 
This happened in an instant, from max cool, high fan speed to slow.  There was no sudden power bump or brownout, and we were in the camper when it happened.
 
Anyone else run into this?  I'm also at a loss on who to take it to to look at it - an RV dealer or an A/C guy...

A lot of A/C units have a special relay that controls the high speed on the fan. Might check with the manufacturer to see if your A/C has a high speed fan relay. It may have burnt out. It happens in an instant, just like a light bulb blowing.

[wynot]

A lot of A/C units have a special relay that controls the high speed on the fan. Might check with the manufacturer to see if your A/C has a high speed fan relay. It may have burnt out. It happens in an instant, just like a light bulb blowing.

Haven't gotten a chance to take a look at it (yet).
 
RV service dept told me to plug it in at home and see it if runs correctly, they suspect that the campsite wasn't providing enough amps.
 
Like I said above, I haven't gotten a chance to open it up and try it at home, but would the fan only settings require a large amount of amps too?

[wavery]

I suppose that may be a possibility. Doesn't seem very likely though.

I've heard of campgrounds that don't have enough service coming in to service all of the campsites if everyone is turning on their A/C units. That's a good heads-up for everyone. It's a good idea to carry a volt meter with you and if this sort of thing happens, check the voltage to your outlets. If the voltage is below 105v, I would consider turning off the A/C. If it's below 100v, I would definitely turn off the A/C. If it's hot out, start the generator (if you have an adequate one) or just suffer along.

Running the A/C on low voltage puts a tremendous amount of stress on the compressor and may burn it out in a relatively short time.

You may be able to pick up a couple extra volts by unplugging from your campers outlet and plugging into the CG box. I would only recommend doing that with a 25' long 10g or 12g extension cord.

[wynot]

I suppose that may be a possibility. Doesn't seem very likely though.
 
I've heard of campgrounds that don't have enough service coming in to service all of the campsites if everyone is turning on their A/C units. That's a good heads-up for everyone. It's a good idea to carry a volt meter with you and if this sort of thing happens, check the voltage to your outlets. If the voltage is below 105v, I would consider turning off the A/C. If it's below 100v, I would definitely turn off the A/C. If it's hot out, start the generator (if you have an adequate one) or just suffer along.
 
You may be able to pick up a couple extra volts by unplugging from your campers outlet and plugging into the CG box. I would only recommend doing that with a 25' long 10g or 12g extension cord.

I agree that it doesn't seem likely, because the condition existed for a couple of days and throughout the days.  I checked at 6 am and it had the same problem.  The multimeter was the ONLY thing we didn't have on this trip.  I would have immediately checked voltage.  Our little TV filled out the picture tube when I turned it on, but I think that has a tolerance of 90-135Vs.
 
The campground was old enough to possibly be underserviced, but 30A was the standard connection.  We didn't have the big rigs running two A/C units on 30A/smartswitches, but we had enough older campers, so who knows what draw the older units were pulling?

[ka9nyn]

Remember folks, as the voltage drops off, the amps will rise to maintain the wattage drawn. Hence you can burn wiring, damage motors, etc.

At the nuke plant, we even have low voltage protection for our large motors just for this reason.


Good camping to you all.

Dave

[zamboni]

When we got our Coleman, the AC worked fine.  Took it camping, and it didn't.  Took it to the dealer, it did.

The service guy explained that if the voltage drops low enough, the Coleman Mach AC units will not be able to start up the compressor.  Everything will look like it is fine (fan will blow full speed, which it was doing), but will be blowing not-cold-air.

So, that wouldn't explain your situation -- if you had low voltage, your compressor would not work... but your fan pulls so much less so it would run fine.

Still, it is a good idea to throw a cheap voltmeter in your camper.

[wynot]

Still, it is a good idea to throw a cheap voltmeter in your camper.

First trip out of the season, the voltmeter was the only thing that didn't make it in...do we have this, I don't know, toss it in...don't we have that, I don't know, toss it in...

[wynot]

Sure enough, it's not the voltage or amperage, so I guess I've visiting the service dept this coming week.