Ignorant fool plugs 30 amp rv into 220

My electrician buddy wired me up a 30 amp plug for my rv, but like a lot of electrians he didn't know 30 amp rvs are 110 and made the mistake chronicled here:

http://www.noshockzone.org/accidentally-plugging-into-240-volt-outlet/

This is in my 1999 Itasca 37 foot Suncruiser, btw.

He was just trying to help me out, not his fault, I should have done my homework beforehand rather than after the fact.  So i plugged my 30 amp rv into 220 for a minute or so.  At one point there was a very loud pop behind the breaker box with a brief smell of burnt wiring or something. 

To make a long story short, this happened about 48 hours ago and I have increased my knowledge of rv wiring about a 1000 fold since then, have done tons of reading, etc.

It seems I got lucky, I fixed the plug to the proper 30 amp configuration, of course.  I went through the whole coach, circuit by circuit.  My first concern was the converter, but it is producing a steady 13.75 volts and seems to be ok.

My next biggest concern was the Intellitec EMS system, but it seems to be working fine.  At least the display is showing the amp load, it's detecting the 30 amp service and also the generator service when I ran that for a while.  My reading suggests the frig is often fried by this also, but mine is fine. The front air conditioner is fine, too.  TV is fine, too even though it's ancient and I wish it had fried.  i have checked all the receptacles and 12 volt systems and they seem ok.

The problem is the back air conditioner, the fan runs fine,  but when you turn it to cool the fan turns off and the unit groans a bit, that's all.  I know the thermostats have a built in delay, but I couldnt sit there and listen to it groan, was worried about damaging it further.

So I guess the unit is destroyed or is there some hope of fixing the wiring or some intermediate part?  Haven't had time to research this part yet.  Maybe it's time for me to split the rear a/c off onto its own 20 amp circuity the way some have done.

Would appreciate any suggestions.  I unscrewed the breaker box panel and looked at the wiring behind there, no obvious problem.

No fuses blew on the converter or on the intellitec system, I guess the breakers cutting off protected them.

Are you sure the rear a/c was ok before the 220v affair? The "groan" sounds more like a failed hard start capacitor, or maybe a seized compressor. At any rate, you need to start a full scale diagnosis of the a/c and don't pre-judge that the 220v shock is the root cause. All indications are that you really lucked out!

Thanks for the quick reply, want to say thanks again for all the help I've gotten on this forum.

If my wife complains, I'm going with your idea but just between you and me it worked fine before.

Mosagra said:

At one point there was a very loud pop behind the breaker box with a brief smell of burnt wiring or something. 

Click to expand...

I wouldn't be able to sleep in my rig not knowing what the pop was from and what the burnt smell came from. You need to find it. The pop, may have been a breaker tripping but I don't know what the smell was from. If after a thorough search for burnt wiring, if it was me, I would replace all the breakers. The smell may have come from one of them. It's a cheap repair compared to what you could have ended up with.

High voltage will not trip a breaker, only high amperage. It sounds to me like there may be a melted (loose connection) that likely contributed to the smell, and could very well also be contributing to your AC problem. I would unplug from shore power, make sure any inverter is off, and pull the breaker panel apart and check for loose or burnt wires within the panel. If it blew the main breaker, especially check the condition of the neutrals.

You guys are awesome, thanks so much!  I did unplug from shore power after testing each circuit.

First thing I'm going to do is pull the panel out again, unbundle each wire bundle one at a time and look for burnt wire.  It was putting 110 back through the neutrals so there definitely could be a burnt neutral there.

the loud pop happened when I was turning on a breaker, I thought it was the converter breaker but might have been the rear ac.  Replacing the breakers will be second on my list.

To further complicate things, now I'm not so sure the rear ac was ok, my parents stayed in there for three days plugged into just 15 amp circuit.  I know at one point they turned on the front ac, maybe they turned the back one on as well? I told them not to turn on either ac but I guess they forgot that part.

Curt in KY

Generally motors can take a short burst of dual voltage, (Caps, not so much but motors can) though I have seen them burned out by over voltage so I won't say it can not happen, I'm in kind of a battle over one now. but that's a very old non-rv story.

And it was his fault, the TT-30 outlet has 125 volt maximum clearly printed on it, all you have to do is LOOK to find it.

I know this because many posts here on this and other forums such as this thread.... Thus In installed my own, and I did look.

I doubt if there is any problem with the breakers - they are usually rated for much higher voltage than what you experienced. And if they got high amperage, they would trip. Wiring insulation is usually rated for 600v or more as well. It's the possibly high amperage that flowed (when something got overwhelmed by the 220v) that may have burned something by overheating, usually a connection somewhere.

If you have any transformers anywhere, might be a good place to look for a burnt smell.

A capacitor will make a very loud pop and a burning smell when the wrong voltage is applied. I would still inspect all wiring. Before you trash the AC check the starting cap on the AC. Vary easy to remove. The ones I have dealt with were plug in. Just take care it will be charged if good and can give you a bit of a jolt. There will also be capacitors in the power supply that could have been damaged. Look the circuit board on the power supply over if you blew a cap you will have no problem seeing it.

Ok, so I am back to work on this after some other events took precedence.

Rear air conditioner just groans when I turn it on.

The hard start capacitor is on the roof attached to the a/c, not behind the panel, right?

The way I'm reading, not all air conditioners have hard start capacitors, but some people choose to add them on?

Curt in KY

All air conditioners have starting capacitors and they'll be inside the roof enclosure.  Go up on the roof, take off the A/C shroud and look for a small metal can with two terminals coming out of the top.  There should be one for the compressor motor and another for the fan motor, but sometimes they are combined into a single can.

A hard start capacitor is a capacitor and relay in a single unit that is brought on line for a few seconds when the compressor starts.  It's purpose is to stretch out the starting surge, letting the compressor come up to speed more gradually while reducing the peak current.

My 1994 isn't too much older than his and I have 3 caps. A start and a run cap for the compressor, and a cap for the fan. Not all caps are metal. Maybe more specifics are needed.

You said the POP came from in back of the breaker panel..... On many RV's that is where the converter is located.

one item found in many pieces of electronics is a device called an MOV (Metal Oxcide Varisistor) this is a small ceramic or epoly disc, looks like a disc capacitor but operates differently,, at 120 volts ac RMS it has a very high resistance, but if you top the break down it becomes a very near short.

These clip spikes that happen when things like Air Conditioners cut in or out.. Very good at it,  they are the active component in many "Surge Protectors" (In quotes because a genuine surge (Sustained high voltage) they... Sound like a fire cracker.

IF your converter was protected with some of these, they (or it) would have gone POP as you describe, however the converter could still work perfectly.. Since they are not essential to the operation of the device.

You can get a new part and replace it.. IF you find that is the case, I can assist.

Can't tell you how much I appreciate all this information.  The converter is working,  btw.  We are gonna get down there and really look at all this tomorrow night.

Vaguely anecdotal, but...

Last year we had some strong winds, and that in combination with old electrical wiring with bad insulation resulted in bare wire crossing on the poles. The neutral melted and snapped, resulting in 220v surging through my house. Inexplicably, there was a loud popping from several places all at once which turned out to be lightbulb filaments failing. No idea how the juice jumped the switches, but it did. My dad still doesn't believe it happened! We lost two surge suppressors (totally fried), an AV receiver (fried), a electric postage scale (transformer survived, scale died), and our microwave. Everything else survived and has been fine for a year.

As was mentioned, wrong voltage isn't great but wires don't care. It's the stuff at the other end that cares about voltage. Chances are everything in the walls is fine, and you've just got to invest some time testing various components. With patience and a multimeter, you'll get it handled for sure.

And to the O/P. by the way do not feel lonley... This general thread is one of the most popular threads in several RV forums I visit,, A couple years ago we averaged about one a week, that has slowed a bit, but we still get better than one a month.

What about an insurance claim?

That might cover the damages.

Good luck!

If he is a true electrician, he should have known not to set it up for 220V.  I would not use him for any future work.  Dick nvrver

NV, I have read dozens of threads where someone hired a true, licensed, electrician. and got a 240 volt 30 amp outlet.

Have you ever assumed? I try not to do that but in truth, it is hard to do and I sometimes fail and make an assumption, and usually when I do I end up looking like an omelet (Egg on face).

The TT-30 looks exactly like the outlet in my parent's house for the dryer,, I mean EXACTLY in fact the plug fits.

Many Air Compressors, Welders and such are also 240 volt and use an IDENTICAL (appearing) plug, The only difference is the TT-30 is labeled 125 volt max.

The electrician looks at it, he has installed dozens of this shape plug in the past so he ASSUMES it is the same as those 240 volt Dryer/Copressor/Welder/Fryer/Hardware outlets and wires it that way.

This is why it is easy to remember how to spell assume  (just put a hyphen before and after the U)