RV AC Help Needed

[JohnHaggerty]

I'm having an AC problem and need help. I have a 30amp system with 13,500 BTU Dometic AC.

-It can run fine for awhile then kick the breaker. Sometimes a couple of days before becoming troublesome.
-Before it kicks the breaker, I hear a noise inside that I think is coming from a circuit board. What is that board and is is a serviceable part?
-Doesn't matter what campground, so I say it's not available power.
-I've changed starting capacitor, no difference.

Any ideas?

Thanks

 

[BIGNASTY]

Has it frozen up when this happens? the harder it work the sooner it kicks the breaker? or does it not matter, those things never impressed me as items that can be run DAY AND NIGHT as we tried to do in the So Calif Deserts, they are just meant to cool things down not make a refrigerator out of a trailer.

 

[JJPage]

Take a razor knife and split the power cord (without exposing the metal conductors,leave the insulation intact) to the AC unit, so you can separate the two conductors powering the device. Use a clamp on amp meter on one conductor at a time while it is running, this way you can verify whether or not the unit is exceeding 30 amps. If it is exceeding 30 amps, something internal is the cause, maybe the circuit board does have to be replaced, it could also be a hard component, including the compressor. If it is not exceeding 30 amps, replace the circuit breaker as it has tripped multiple times and it's electrical integrity has been weakened.

If you are able to clamp on to the individual feeds at another location safely, without splitting the power cord, so much the better, then you do not have to risk damage to the power cord, but if your are careful it should not be a problem.

 

[p-Bar]

JJ is on the right path . You could go and unscrew the panel and clamp the wire coming off the breaker. If you have a 30 amp service what is the breaker size of the AC ? Agree with JJ your breakers could be bad. Find out in the manual what the AC draws .

 

[Larry Willard]

Your AC should be on a 15 amp circuit. I would check the amp draw, but previously I have just replaced the breaker that was apparently weak and solved my problem.
Larry

 

[Hoefler]

If your blowing the 30 amp breaker, you have more on than you think. The A/C Alone will not trip the 30 amp breaker, if it is an A/C problem, it should be tripping the 15 or 20 amp breaker that feeds it. Are you running the water heater on electric?? What else is running when you trip the breaker?? Water heater, convertor, microwave, coffee pot, hair dryer, etc.., any combination will trip the breaker.

 

[Newt]

With a 30 amp RV, "YOU" have to practice power management. Basically, you can have 2 high draw items on at once. The 3 items you usually have to juggle are the AC, microwave and electric water heater. Run all 3 and the breaker will blow.

Did I tell you I love 50 amp (really 100 amp) service. In our rig, we have a Progressive Dynamics EMS. It gives the voltage and amps for ea leg of the 50 amp service. These are also available for 30 amp service. We can basically run anything and everything in the RV at once without blowing breakers. Yes, we have a washer/dryer.

Newt

 

[JJPage]

I thought I understood that you had a 30 amp breaker servicing your AC unit, my mistake. I now believe what you are telling me is...you are blowing the "MAIN" 30 amp breaker serving the panel? If this is correct, then I agree with the other posters that you are overloading the MAIN feed breaker by running too many appliances at once.

I suspect the noise you are hearing is the AC unit straining under low voltage because of the increased amp draw from other devices. You can measure amp/voltage draw at the MAIN power cord as previously described, turning on one appliance at a time until you exceed it's limits, all your appliances may be in perfect working order, the MAIN service might have to be upgraded to a 50 amps....or the MAIN 30 amp breaker simply replaced.

 

[Wingate]

yep, as others have stated, you need to be able to measure the load on the service line before and after the breaker. Need to know what all is running when this happens. Make sure you arent plugging into an extension cord or other substandard device as well. a worn/loose receptacle will cause excessive amp draw. Is one of the plug lugs discolored?
SOMEWHERE, there is a chart for showing the power demands of all the electrical components in your camper. I know both of my Jaycos came with them. If not, you could always read the owners guide of each of the devices and/or find the dataplate on each device or possibly find a universal one online. It will help you manage your power better. Some people will buy a 30/50 adapter cable and plug their units into 50A service when camping as many times the places you are camping struggle to get 30A. Startup amps is what usually gets you. If the a/c and HWH are running and you try to use the microwave, it will most likely put u in the dark.

 

[JohnHaggerty]

Thanks for the responses.

Problem still exists with all other major appliances off, so I don't think it's a overall current issue.

Main breaker is a dual 30a/20a.

I'm thinking the breaker might be going bad. I have a replacement and plan on changing.

I'm stumped on the noise I hear as it is having problems and before it kicks the breaker.

Thanks,

JOhn

 

[RVTRKN]

You need to know the amp draw of the AC first, especially when it makes its noise. Also you need to know the voltage, if its lower than required, it can cause the over amp issue. The low voltage issue is an indicator of a faulty breaker. Check your breaker temperatures and inspect them for overheating. You also need to check your blower motor bearings, if there is play in the bearings, it can be the blower motor. If you have the ability, you can isolate the AC from your RV circuit and run it from a dedicated 15 amp circuit using a heavy gauge extension cord to see if the problem goes away.

 

[SnoKing]

Is the noise you are hear coming for the converter cooling fan? Maybe your converter is going bad. Sometimes the converter is just plugged into a duplex outlet. Try unplugging it. What is the condition of your batteries?

Chris