Wow! Unplugged 50 to 30 amp adapter....50amp female melted

Using a cord rated for 30 amps that is plugged into a 50 amp plug is not really the safest way to plug in. The 50/30 amp adapter states on the packaging when you purchased it, that it is to be used with a 30 amp breaker.

This is not all the uncommon. At least all you damaged was your adapter and not the shore power cord. Contributing factors:

1. Loose connection. Worn out receptacle in CG pedestal. Poor connection can cause increased contact resistance. 30 amp receptacles in CG pedestals on average get a lot more use than 50 amps due to the higher number of RVs with 30 amps.

2. Dirty connection. Caused by plugging in the shore power or adapter live all the time. The converter momentary inrush current causes pitting of the plug blades and inside the receptacle. Pitting attracts dirt which together increase the contact resistance. Never plug in live.

3. Low CG voltage along with running your AC unit. Running an AC on low voltage causes the current to increase. You can end up running at or close to 30 amps for extended periods.

It is important to note that you cannot draw more than 30 amps due to the 30 amp main breaker in your converter panel so that is not a factor.

You should periodically check the blades on shore power cords and adapters and clean with fine sandpaper. You can't check inside a receptacle or the female end of your adapter and I don't know of a way to clean pitted contacts inside either. But if the plug blades on an adapter don't look very good, the female end may be bad too.

For those with 30 amp RVs, you can use an 18" 30 amp to 30 amp extender like the Camco #55205 for under $20: This way, if you have no choice in plugging into a crappy and questionable looking CG pedestal, you will only lose the extender and not your shore power cord which could be a disaster when travelling. And again if you have 30 amps, if a 30 amp CG pedestal looks to be poor, it helps to use a 30 to 50 amp adapter because 50 amp recepts. are usually in better shape.

Stayed 2 weeks in Floirda. With the 30amp plug with just AC and one other appliance (fan) kept tripping breaker.

So, because the power pole 30A breaker kept tripping, you assumed that hooking to the 50A supply would solve your problem? You melted your dogbone because you continued to draw more than 30A thru the power cords with no over amp protection. The 30A main breaker in your coach should have tripped, but didn't - I would get that checked out before worrying about the dogbone.

BTW, you probably had more units drawing power than mentioned; i.e., Fridge, HW heater, TVs, hair dryer, microwave, toaster, coffeemaker, etc.

I always ( when 50 amp is available) use the 50/30 adapter. chances are the 30 amp plug got hot and started burning ever so slightly and then got worse. The most power you can pull is 30 amps because the main in the camper is 30 amps. If plugged into a 100 amp plug the most current you can pull is 30 amps so there is no danger of overloading the supply cord. In the event of a short the 50 amp breaker would trip faster than you can blink. # 14 copper is considered a 100 amp fuse link so it would get darn hot and you could maybe start a fire, but you will never overload a #10 cord because of the inside main of 30 amps. I carry a replacement plug in case mine gets damaged. Too many pedestal outlets are burnt which just compounds the problem

I find 30 amp plugs and outlets do tend to get hot.. 50's not so much.

Even when it's a 30 amp plug on a 30 amp outlet in a park

I clean mine often, this helps.

Roger10378 wrote:

accsys wrote:
It sounds like you were using an adapter to plug your 30 amp cord into a 50 amp pedestal receptacle because you kept blowing the 30 amp breaker when using the 30 amp receptacle. If so, that allowed you to pull 50 amps through your 30 amp cord which it is not designed to handle and you could have easily melted a connection. Lesson here is to manage your electricity use better. If you are blowing the 30 amp breaker, reduce your usage by using propane for everything that you can and turn off 120V items that are not being used. Don't plug into 50 amps as your rig is not designed for it.

I think this is the correct answer. You were using near 30 amps all the time so you were popping 30amp breaker. You change to 50amp available so the breaker is no longer the limiting factor so the first 30amp piece of equipment is the limiting factor. I would also inspect the cord and anything else on the 30amp side of the trailer as it was seeing near max amps for a whole week.

I would also find out why you are using 30amps so much of the time. You either have other things turned on that you don't realize, or you have a problem with your AC or fan.

Nope, the 30A CB in the rig will limit the draw to 30A even with the 50/30 adapter. There is no reason to suspect that the 30A CB was defective and allowing excessive current since it was tripping.

Likely the 50A plug had better voltage or the draw changed between the 2 plugs. But either way limit the draw to 80% and yes clean all of the contacts.

accsys wrote:
It sounds like you were using an adapter to plug your 30 amp cord into a 50 amp pedestal receptacle because you kept blowing the 30 amp breaker when using the 30 amp receptacle. If so, that allowed you to pull 50 amps through your 30 amp cord which it is not designed to handle and you could have easily melted a connection. Lesson here is to manage your electricity use better. If you are blowing the 30 amp breaker, reduce your usage by using propane for everything that you can and turn off 120V items that are not being used. Don't plug into 50 amps as your rig is not designed for it.

I think this is the correct answer. You were using near 30 amps all the time so you were popping 30amp breaker. You change to 50amp available so the breaker is no longer the limiting factor so the first 30amp piece of equipment is the limiting factor. I would also inspect the cord and anything else on the 30amp side of the trailer as it was seeing near max amps for a whole week.

I would also find out why you are using 30amps so much of the time. You either have other things turned on that you don't realize, or you have a problem with your AC or fan.

It sounds like you were using an adapter to plug your 30 amp cord into a 50 amp pedestal receptacle because you kept blowing the 30 amp breaker when using the 30 amp receptacle. If so, that allowed you to pull 50 amps through your 30 amp cord which it is not designed to handle and you could have easily melted a connection. Lesson here is to manage your electricity use better. If you are blowing the 30 amp breaker, reduce your usage by using propane for everything that you can and turn off 120V items that are not being used. Don't plug into 50 amps as your rig is not designed for it.

We have the type of connection where the power to the rig is thru a permanently mounted male plug on the side rather than a cord that slides into the storage area. I recently learned that the movement of the rig may make the contacts also move between the male connections and the female connectors on the cable that hangs down. That small movement acts like a loose connection and can cause them to overheat under load.

Many times the campground 30 amp receptacles overheat, and then the brass inside the plug loosens, and will not grip the 30 amp plug tightly. This can cause overheating and in extreme cases like yours, arking and possibly a fire (when more extreme!) The fire will not burn hot enough to melt anything other than the electrical cords, and not damage the RV at all, as it should trip the 30 amp circuit breaker.

So if your 50 amp RV cord is still good, then you only need to replace the 50 to 30 amp adapter, as it has overheated to much, and now requires replacement.

I had a 30 amp receptacle overheat on me. I noticed that the voltage was only 105, so I got out my booster transformer (it was about 105F outside!) and found the plug very hot. By plugging in my 30 amp RV to a 50 amp receptacle, I found now I had 120 volts - even with the air conditioner running!

Good luck!

Fred.