HEATING?AIRCOND?ELEC PROBLEM? - Montana Owners Club

Montana_1929 · 10-25-2005, 03:59 AM

Last spring on a trip from SoCal to Sacramento my heater wouldn't work. I tried it at three different campgrounds and again after we were home. So I took it to the techs for repair and it worked fine for them? They did however replace the blower due to noise. It has worked fine since for me too? Also last june we were in Utah for a week and the AC was acting up a little. We had to start it up on low and let it stablize a bit then switch to Hi. If we started it on High it would just hum and pop the ac breaker after a few minutes. This past weekend we went out and no ac at all, just hum and pop breaker. Any ideas???

Dave

Broome101 · 10-25-2005, 01:31 PM

Had similar issue happen to us turned out to be low 120VAC voltage coming from campgrounds, same thing at home had bad voltage drop. Since we fixed the problem at home ran true 50 amp service to RV port with #2 wire going to it all haven't seen that problem again. Not sure that's your problem or not but something top look at.

uhftx · 10-25-2005, 02:15 PM

Hi Dave

First the Alternating Current could be a problem. The Air Conditioning is a system basically comprised of a compressor, evaparator and condenser and miscellaneous systems.

It sounds more like electrical to me.

It sounds as if there isn't enough current being supplied to the AC unit. OR the AC unit is trying to draw more current than is available on High when you first start the compressor could be a culprit. It sound as if the combination of the blower motor and compressor starting at the same time is drawing more power than your circuit can supply.

The other thing that is related to the compressor but not to your electrical supply is that the AC unit is charged with too much refergerant. This could cause the compressor to try to draw liquid refergerant into itself causing the circuit breaker to trip.
[This is normally not an issue, more likely to leak out]

The refergerant R-12 or R134a which is used now, is both a gas and a liquid depending upon the pressure and temperature. At low pressure the refergerant is a gas. This gas is compressed into a liquid form which is then passed to the condenser coil (heated and at high pressure) when the outside air is passed over this heated coil it absorbs the cool outside air which is passed to the evaparator coil(as a cold liquid) which your fan blows across exchanging your inside hot air giving you cold air. This is all possible because of the expansion valve that senses the evaporator temperature and allows your refergerant in liquid form to be transformed back into a gas at low pressure.

The compressor is designed to compress the gas refergerant. If for some reason the compressor tries to compress the liquid well guess what liquid won't compress as much as gas vapor (which causes the compressor to overload).

I don't think you have anything wrong with your Air Conditioning Unit. It should of been checked at the factory. It is unfortunate that the systems installed into RV's are sealed units and there is no way to check the low or high side pressure as they sit. It is possible to remove the refergerant and install the apropriate fittings but it requires the units to be drained and a vacuum pulled and recharged after the fittings are installed.

I would find someone with a good electrical troubleshooting background and ask them to have a look. Notice I didn't say an electrician. Nothing against electrican's. My son is one. Legally you may need one. But when things are not always right, their troubleshooting skills are somewhat lacking. What you want is someone who can figure out a voltage and current drops in AC circuits. BTW: I have 6 friends that are elecricians Sure they can wire to the local and NEC but I wouldn't ask them to troubleshoot a Radio because it works on electricity.

A good question to ask is can they solve Kirchoff's voltage and current laws. You will of found the right person if they say yes. But, do they have the equipment to do the analysis.

Wishing you the best
Sorry I couldn't be more help.

Montana_1929 · 10-26-2005, 06:45 AM

I too am leaning towards it being an elec current issue. I had it pluged in at home to a dedicated 20amp circuit and while it did come on at the low setting, it still poped the 20amp breaker for the A/C in the 5th wheel. This indicate (to me) that either the A/C is pulling too much current or the circuit breaker is faulty? I have checked all the breakers in the coach for secure connections and they were/are. Thanks for the inputs, and I'll let you if/when I get answers...

Dave

ols1932 · 10-26-2005, 07:29 AM

Quote:

quote:Originally posted by sjordan007

I too am leaning towards it being an elec current issue. I had it pluged in at home to a dedicated 20amp circut and while it did come on at the low setting, it still poped the 20amp breaker for the A/C in the 5th wheel. This indicate (to me) that either the A/C is pulling too much current or the circit breaker is faulty? I have checked all the breakers in the coach for secure connections and they were/are. Thanks for the inputs, and I'll let you if/when I get answers...

Dave

Breakers do go bad. I had to replace one for my AC in my rig a year ago. What happens is if the breaker happens to get warm (a lot of current passing through) a lot, the breaker tends to get weaker. It's like a lot of breakers in older campgrounds. On really hot days, those breakers have a tendency to trip a lot quicker than they do during cooler days. My replacement breaker has worked like a champ ever since.

WildBigBill · 10-26-2005, 07:41 AM

You have to check your power where you are plugged in. Make sure you have close to 110v or more, especially after the A/C is turned on.

sgf · 10-26-2005, 12:30 PM

Sounds like a voltage drop problem ,I doubt if the a/c is the culprit,it does need good voltage to start up with both the compressor and the fan starting at the same time,btw our rv a/c units are charged with refrigerant 22,they are nothing more than a window a/c under a different housing and with different control system.

Montana_1929 · 10-27-2005, 12:40 PM

Quote:

quote:Originally posted by sgf

Sounds like a voltage drop problem ,I doubt if the a/c is the culprit,it does need good voltage to start up with both the compressor and the fan starting at the same time,

As I stated in my 2nd post, when I checked it at home it was on a 20amp dedicated circuit, and there is solid 118vac. I left it with my service tech today sooooo, I should know soon...

Dave

owenwetzel · 10-27-2005, 02:35 PM

Had simular experience. If you are trying to operate off a 110 or 120 outlet make sure you use 12v lighting only. And make sure your water heater is on lp only and refrigerator on lp. It only takes 12v to operate igniters and leaves 110v for AC.
We have had to use 110 outlets at some city or state parks as that was the only electric soure available.

Montana_1929 · 10-29-2005, 04:50 AM

UPDATE*** I called the service tech and at least it's still broke (won't work for them either). They are awaotong approval from Keystone to proceed with trouble shooting and diagnosis... Should find out within a couple of days. I'll post when I do...

Dave

Montana_1929 · 11-08-2005, 06:16 AM

Well I guess when I got the update the girl at the service center was talking about a different 5th wheel with AC problems. As it turns out mine worked fine for them??? I brought it home and it works for me too??? This intermitant crap is starting to get to me...
BTW...Keystone says that since my warrantee expired with them 3 weeks before, TUFF!!!
Oh well...

Dave

sgf · 11-08-2005, 06:59 AM

Good luck, hopefully with good voltage all will be fine,when checking the voltage do not just check the voltage when nothing is on, check when the equipment is trying to run then see if you have a major drop in voltage,hopefully keystone will step up if you have more problems.BTW,Your Domectic a/c unit has a five year warranty,just make sure the servicer is an authorized domectic service center and all should be covered,just had a problem with our landing gear and we are out of warranty;dealer said it would cost a couple hundred bucks, called lippert and they have a two year warranty and are sending me the parts free of charge;but of course I have to do the repair so make sure you read all of your warranty papers, they are very deceiving.

Montana_1929 · 11-10-2005, 05:11 AM

Thanks for the info and idea of checking voltage when turning things on. At least I have the 7yr service plan to cover big stuff. Time will tell... We're going out this weekend and although I doubt I'll need the AC, I will check it out just the same...

Dave

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