Community Forums

gail99 · 08-20-2009, 07:51 PM

Just trying to get a little insight into what the problem may be with our travel trailer. It is hooked up to shoreline power and we just replaced the battery with a deep cycle. When we run the air cond. or the heat the breaker trips and power shuts down (no lights etc.) . I have also tried to operate the slides and their is not enough power for them either. When I try to troubleshoot a little with the panel box (and the air off) the converter make a funny noise. So if I replace te converter do you think this may solve the problem. Any suggestions? The trailer is a 27ft. wildwood le.
Thanks, Gail

450Donn · 08-21-2009, 09:11 AM

The converter has nothing to do with the AC unit not running. All the converter does is take the incoming 120VAC power, convert it to 12VDC and sends some to the battery and some is consumed for lights etc. there is also a distribution panel generally attached to the converter that has fuses/breakers on it. These control the various lines in your trailer. First thing is to check that you did not hook the battery up back words. Then start your search for why there is a lack of power. starting with the 120VAC side. You could have a dead leg, bad ground, open wire someplace or simply a blown fuse.

wa8yxm · 08-21-2009, 10:12 AM

I agree with Donn. the converter's job is to convert 120vac to something around 12 volt DC (The actuall voltage varies with the state of charge of the battery, but just saying 12 volts is way easier)

And normally this has absolutly nothing to do with the air conditioner, Carrier V's are an exception as they use 12vdc for control power.. But even that will not trip a breaker

Now, what does trip brakers, 9 times out of 8, is current, in fact that's the ONLY thing other than your finger that can trip them

An air conditioner, if properly operating draws in the neighborhood of 10 amps. STARTING, it can draw 40-50 or more but running it's about 10 amps, give or take a bit depending on the make, model, size and weather conditions.

A water heater, around 12 amps.

A microwave 7 to 12 amps

A fridg 3-4 amps

A converter,, Depends on the state of charge of the battery,, Mine (I have two by the way) Can pull 10 amps.. EACH, if the battery is in a serious state of discharge.. Most Trailer units pull a bit less, say six to eight.

So, 12 for the water heater, 8 for the converter, 10 for the AC

30 amp breaker will have one thing to say about that load

CLICK (A sustained load of aroudn 28 amps will click it)

Another issue, one which will affect me in a few days when I change parks.

If the park voltage is running a bit ...low.. That air conditioner will respond by drawing more current to make up for it.

So 10 becomes 11 or 12 or 13 and CLICK happens even faster

Dang thing trips the 20 amp in my coach And I'm feeding via a Hughes Autoformer too boot!!!!!!

Paul R. Haller · 08-25-2009, 11:55 AM

The one comment here that makes me worry somewhat is that the original poster says that after the breaker trips he has no lights etc. Lights in a trailer work on 12 volts DC not 110 AC.
If your lights do not function properly its got to be the 12 volt side of things which can be the converter. My trailer air or heat will not function either if my 12 volt battery output drop to 0 because they both use 12 volt control voltage. I do however agree that the 12 volt side of things should not trip the breakers.

This is how I would proceed. Get a volt meter that reads both 12 volt dc and 110 AC. Charge your battery out of the trailer using a car charger. Turn off all breakers and all appliances in the trailer and plug shore line into 110 AC. Flip on main breaker and see if you have 110 using voltmeter at the mains. If yes, proceed to flipping on the Microwave and see if that works. Continue flipping on breakers checking to see that 110 is present at all on branch circuits. Now check your battery with the converter unplugged. Is it reading 12.65 or higher? A fully charged 12 volt battery will read between 12.65 and 12.8 volts. now plug in the converter and check again. If the converter is working , the battery voltage in the trailer should now read 13.5 volts or higher. If not check that there is 110 at the plug the converter plugs into and check fuses at the converter. If all is ok and your converter is still not producing 13.5 volts or so, the converter is shot.

Now start turning on all appliances one at a time. Microwave, then electric hot water, fridge, etc and see when you start tripping the breaker. A 30 amp main shore power should allow you to use just about 28 amps of current. You will find that, at least in my trailer the ac, the electric hot water heater, tv, fridge and little use of lights is about it. If I turn on the mirowave in addition... Bam, I blow the breaker. Hair dryer, ciffee maker all draw a lot of current. If your battery is low and needs recharging in addition to the draws from appliances, and your converter is working, and that will draw current too. Make certain (as was mentioned above) your battery is hooked up properly and is charged.

Good luck and keep us posted as to what you find.
-Paul R. Haller-

mrschwarz · 08-25-2009, 08:42 PM

Sometimes, the power distribution in a trailer combines both the 120v and 12v into the same unit. If the main breaker trips, it could take out the 12v converter at the same time as the AC. If the battery is charged, it should keep the lights on, unless the battery is wired through the converter.

Jeff_in_The_Dalles · 09-03-2009, 09:35 AM

It does sound like the battery is dead, so I wonder if the converter is dead and drawing a bunch of 110AC?

Then add the load of the air conditioner, and it trips the AC breaker?

I'd verify the polarity of the battery first, then check it's voltage with the trailer unplugged, and with the trailer plugged in and the converter/charger on.

That should tell you a lot.

If you have an amp meter, it would be interesting to see what the AC current draw is with just the converter on.

Twotenda · 09-08-2009, 01:38 PM

Hello, I experienced the same problem this weekend.. I was plugged in to 30 amp service at a campgrounds, 2 new house batteries (not fully charged) , and with alot of lites on , the furnace would kick in and poof, out goes the lights... But still had 110 service (roof fan still on , outlets still worked).. Battery showed 11.99.
Was told the converter is bad, or charge the house batteries up to 13.8 .... so thats where I stand .. I ll keep you posted.. Paul

Twotenda · 09-08-2009, 02:04 PM

Also , with the generator running, I have none of the problems.. I m wondering if mine could be the converter.. Thanks for any help... Paul

Paul R. Haller · 09-08-2009, 02:35 PM

Unplug the Converter from AC and see if the outlet the converter plugs into is hot. If Yes, disconnect the red or black positive wire from the converter to the battery or fuse block and measure the voltage at the converter with the coach and converter plugged into 110 AC but not connected to +12 volts. The output of the converter should be 13.5 volts or higher. If no, check fuses and converter.

11.9 volts is nearly dead. Charge your batteries using a car battery charger. The fan and the ignitor board on the furnace uses 12 volts DC for the fan and the control voltage. If your power output drops below about 11.5 volts the furnace won't light. Why the lights go out is a mystery but I suppose if the battery is really low the lights would not work or the circuit breaker could open. Charge the batterise all the way up and see what happens..