Burning Up 50 > 30 Adapters

[canesfan]

Finally remembered to ask about this, although anymore I just always use the 50 amp cord.

I've burned up 3 50 > 30 adapters with my present rig. Usage is adapter coming from the 50 amp connector on the side of the rig, going to a 30 amp cord, going to a 30 amp outlet. It has happened once at my house where I have a 30 amp outlet, once in a campground with a fairly new 30 amp outlet, and I forget the third occurrence.

I have only one AC and I do not run much of anything at one time. I am a power miser.

The time at home I went out one day to find the side of my rig black above the power cord, the time at the CG I was going for a walk and came around the corner to see smoke coming out of the adapter. Needless to say all adapters were fried, one is still laying in my yard welded to the cord.

What could be causing this? I doubt I could have ended up with 3 bad adapters, so it's got to be something else. A bad cord? Although I think it happened with 2 different 30 amp cords if I remember right. Something in my rig? I HATE that 50 amp cord and shouldn't even need it with what I am using, but I'm hesitant to use a 30 amp anymore until I can figure out what is wrong.

[Racebug]

a loose wire will do that. once it has happened the first time, it will happen faster and easier the next time. Unbolt/screw the shore plug outlet from the camper and look at the wire connection on the back of it.

[bobbecky]

There is a reason why your rig is equipped for a 50 amp service. If you had an EMS with a display, you might be surprised at how much electric load you have. If you are close to 30 amps continuously, that 30 amp adapter will get hot to the point of melting the plastic parts and eventually doing what you have experienced. Its best to use the heaviest cable you have at the rig end and if you have to, use the adapter where you plug in at. You get line loss in the cable which is voltage drop at the trailer end of the cable, and the smaller the wire is, the greater the voltage drop you will see. So, at the house end, your voltage may be good, but you will have higher current (amps) all the length of the cable which causes heat. Best to just buck up and use the big cable at the trailer.

[JRTJH]

Another possibility is plugging in the trailer "under load". That causes arcing at the pins which leads to corrosion, overheating and resistance at the connection. Always turn the campground pedestal circuit breaker off, plug in the "trailer end" of the power cable, then plug in the pedestal end and turn the breaker back on.

[canesfan]

Thanks for the answers so far.

1. I will look for a loose wire. I do know that can cause issues but didn't think about it.

2. Not to argue your point, and I can't say for certain, but I'm pretty sure the reason it has 50 amp service is it is wired for a second AC, which I don't have...yet, otherwise it most likely would only have 30 amp service, but I could well be wrong. There's nothing more/different in this one than others I have had and I never had a problem melting/burning a 30 amp cord/plug. And like I said, I'm a power miser. I really doubt I am stretching the 30 amp power limit, and each time this has happened I was not running the AC nor much of anything else. I understand I'm probably better off fighting with the 50 amp cord and have been doing that since the last time the smoke escaped. But I would like to figure out what is causing this if it's something besides the possible overuse of electric through a 30 amp cord.

3. Thanks, I do shut off the breakers before I plug in. Habit.

[sourdough]

Do you have, or are you using an EMS/surge protector? I think it would shut down the power before you got into the situation you are describing and would let you know what's going on.....

[canesfan]

No I don't. I had a portable 30 amp one that I got rid of when I got this unit and haven't replaced it yet.

[sourdough]

I gather it works fine if you use a 30>50A adapter at the ped, the 50A to the trailer then you plug it in. When you use the 30A cable plugged into the ped, then put the adapter on the 30A to upsize to the 50A at the trailer receptacle you have issues.

In that case the trailer should be fine (if something isn't toasted from the other times). Something is wrong with the 30A cable or the adapters you're using at the trailer. Have all the adapters been the same brand, ie; Camco, Atwood, etc.? Since you don't have an EMS you might try this to see if it tells you anything; take your 50A cable and plug it into the ped with adapter. Take a meter and read the end of the cable. You should have 2 hot leads (sides), neutral (top if I recall) and grd (bottom). Read each side to the neutral then ground. Record those readings (voltages). Plug the 30A cable into the ped, put the adapter on the trailer end then read those same voltages from the same pins as before. Are they the same as the 50A cable? Are the voltages on the same pins?

The adapter at the ped takes the 1 hot leg of the 30A then splits it on the 2 hot legs of the 50A. The adapter at the trailer takes the 1 hot 30A leg and then splits it to go out on the 2 hot leads going into the trailer. Apparently the one you use at the ped does it without an issue and whatever you're using at the trailer, or the 30A cable, is causing a problem.

[Johnny's Journey]

The adapter at the ped takes the 1 hot leg of the 30A then splits it on the 2 hot legs of the 50A. The adapter at the trailer takes the 1 hot 30A leg and then splits it to go out on the 2 hot leads going into the trailer. Apparently the one you use at the ped does it without an issue and whatever you're using at the trailer, or the 30A cable, is causing a problem.I'd be curious to know exactly what is being turned on even though OP is using power conservatively. The weakest link is the splitting as you've mentioned. Edited add on. 2-50 amps lines now condensed to one line is like 100 amps that could try coming thru a 30 amp adapter. A 70% cut of over all usage would have to be met so the adapter can safely survive.

[canesfan]

Let's see, I use a 30 > 50 from the ped to a 50 amp cord to the trailer at home. Have not had a problem there.

I've had 3 different 50 > 30 adapters and 2 different 30 amp cords that this has happened with. It would be pretty out there that all of them were bad, but I guess possible. I can't say what type/brand adapters or cords they were, but they were not all the same brand.

I'll have to try and do the tests on the cords you suggested but I'm not sure I have a 30 amp cord anymore that's any good.

As for what was turned on, the time at the house it would have been the refer, the converter, the radio memory and whatever alarm runs off of 120, I can never remember which is which unless I'm there looking at them. Since it stays in my yard plugged in all the time that's all I have on unless I am out there doing something. At the CG it probably would have been the same. Since I was going for my walk I would have had unnecessary things turned off and no one else was there at the time.