A Cautionary (and electrifying) tale....

[bobfrommaine]

I'm sure you're gonna get lots of responses but for what it's worth.
In 35 or so years working on boats, I probably saw 10 of these a year. Boats use the Hubble connectors that are arrayed in a circle (semicircle?) and frequently the hot connector would melt-out just as you show. The issue is contact resistance and is usually because the female plug had insufficient contact pressure. These plugs wear and also any oxidation on the male plug will increase resistance. I recommended to my customers to buy Harley Davidson contact grease. It came in a tube, was about the same viscosity as #30 motor-oil but was not itself a conductor. It prevented corrosion and made plugging-in much easier and prevented (mostly) wear on the female connector. I never thought Vaseline worked as well, and some low viscosity greases had some conductive material in them that caused problems. I use this stuff on my battery terminals and most all connectors on my boats and my RV.
Bob '14 WInnebago 37F Adventurer; Jeep toad.

[Markbirdnow]

[I once had a cord head melt while at a very well known RV repair place that I trust completely. They replaced just the head. It's been years ago and worked fine ever since. It is very water resistant. I do often take a small wire brush to the blades.

[dsavage74]

I have seen numerous posts stating reels have slip rings. Absolutely false!
Not one coach has slip rings for the 50 Amp plug ins.
Beware of false posts!
Lots of misinformation!

[mangles]

Originally Posted by carybosse

I haven't absorbed all of the information contained here, as far as the root cause of problem. I just want to suggest why the replacement of the cord reel might make sense.

I have never had a cord reel like this, but in my understanding, the cord reel is hard wired on one end to the trailer, and then the cord with a plug on end is wound up on a reel.

That means that inside the cord reel are contacts that rotate on some sort of mechanism. The current load had to be carried by those contacts, and those contacts may be difficult to inspect. Think about this in terms of brushes on a motor or an alternator that sometimes need replacing. The repair facility either figures that it is too expensive to inspect, or maybe even impossible to inspect these brushes or contacts. In terms of resistance, I would think these contacts are a larger issue in regards to resistance the the plug itself, more likely to build up dirt, to have dust from wearing down of the contact surface. Not as bad as brushes on a motor or alternator, since it is not spinning at a high speed, but it is not likely designed as robust as brushes are designed on a high speed motor.

My mind is going blank right now with the engineering term for the mechanism that transmits electrical while rotating, but my senior design project in Mechanical Engineering required a component for this. We were more concerned with electrical noise that current load. Found a component in a junk bin on the LSU campus, when I contacted the manufacturer of the component (by US mail, we didn't have this world wide web with email in 1981), they replied back with a question of how did we obtain a component off of a Saturn V rocket? It worked great for our simple needs.

Ding! Ding! I remembered the name of the component - it is called a slip ring.

https://sibley.com/product/slip-ring...UaAvhbEALw_wcB

Most modern steering columns on vehicles are going to have a version of a slip ring to allow the steering wheel to have electrical switches mounted on it while also allowing the steering wheel to make more than 1 full rotation.

And here are the pictures of one such Entegra cord reel with a burned out contact and slip ring.

And not you can not pruchase replacement parts. You have to purchase a complete reel assembly.

[MikeRP]

This thread is great, seems like these discussions come up from time to time and it’s great to read the advice from experienced folks about this important issue.

I had a friend who almost lost his American Heritage Coach to a hardwired EMS. He just happened to be at the Coach and I think it got hit by a surge during a storm and he started smelling smoke. Needless to say he got the fire out before any large damage. But he was lucky to be there. Just food for thought.

That’s why I haven’t wired one on my fifth wheel. I keep a cheep voltage monitor in a plug I can monitor all the time. I think the lowest I’ve seen is 112 volts. And I have one of those progressive surge protectors at the pedestal. I won’t use a dog bone either. Probably should throw the ones out that came w the Coach. I also only have two AC units.

Only other thing I was wondering and maybe it was answered, could the Coach internal grounds on the power supply need cleaned up? Or at least need inspected. How many internal grounds to a Coach of this size would there normally be? I know the Coach gets its ground from the pedestal. I have seen a ground in the front section of my fifth wheel and I’ve really never went looking for grounds internal to the Coach. Tell me if I should.

Thanks for a great discussion.

[Elevensdad]

Originally Posted by carybosse

I haven't absorbed all of the information contained here, as far as the root cause of problem. I just want to suggest why the replacement of the cord reel might make sense.

I have never had a cord reel like this, but in my understanding, the cord reel is hard wired on one end to the trailer, and then the cord with a plug on end is wound up on a reel.

That means that inside the cord reel are contacts that rotate on some sort of mechanism. The current load had to be carried by those contacts, and those contacts may be difficult to inspect. Think about this in terms of brushes on a motor or an alternator that sometimes need replacing. The repair facility either figures that it is too expensive to inspect, or maybe even impossible to inspect these brushes or contacts. In terms of resistance, I would think these contacts are a larger issue in regards to resistance the the plug itself, more likely to build up dirt, to have dust from wearing down of the contact surface. Not as bad as brushes on a motor or alternator, since it is not spinning at a high speed, but it is not likely designed as robust as brushes are designed on a high speed motor.

My mind is going blank right now with the engineering term for the mechanism that transmits electrical while rotating, but my senior design project in Mechanical Engineering required a component for this. We were more concerned with electrical noise that current load. Found a component in a junk bin on the LSU campus, when I contacted the manufacturer of the component (by US mail, we didn't have this world wide web with email in 1981), they replied back with a question of how did we obtain a component off of a Saturn V rocket? It worked great for our simple needs.

Ding! Ding! I remembered the name of the component - it is called a slip ring.

https://sibley.com/product/slip-ring...UaAvhbEALw_wcB

Most modern steering columns on vehicles are going to have a version of a slip ring to allow the steering wheel to have electrical switches mounted on it while also allowing the steering wheel to make more than 1 full rotation.

I believe it is called a clock spring—at least as applies to a steering wheel’s various signals, including the horn.

As for the OP’s post, I think the dealer took advantage of his predicament. A new cord could have been wired to the reel, with no more complicated processes than wiring in a new reel.

[SCVJeff]

Originally Posted by Alpine36

Makes a good case for installing a quality 50A hardwired EMS.

This isn’t an EMS issue. There is no way short of a lightening strike that there would have been an arc path to ground without help. This connection was likely wet.

[SCVJeff]

It’s called a Slip Ring

[Elevensdad]

Originally Posted by Alpine36

Makes a good case for installing a quality 50A hardwired EMS.

I agree. Mine is hard-wired. The fewer connections (plug + receptacle) AKA failure points, the better!

BTW: I’m surprised to learn that high-end motorhomes do not have them as standard equipment.

[Hurricane-TX]

Same thing happened to me a couple of years ago. I replaced the plug with one from the hardware store. 20 bucks and 30 minutes later I was connected and have never looked back. The repair facility robbed the OP.

[Buly]

Originally Posted by dsavage74

I have seen numerous posts stating reels have slip rings. Absolutely false!
Not one coach has slip rings for the 50 Amp plug ins.
Beware of false posts!
Lots of misinformation!

I think you are mis informed. I personally took apart my 50A reel , and was surprised to see the 4 slip rings. Really bad idea.
Next site neighbor with the same year and model Dutch Star replaced his reel for the same problem. Why would I post misleading information BTW?

[jaysigel]

I have had 2 cord winder failures, each causing diffuse damage to appliances and destroying the automatic transfer switch. I won't use them anymore, period. They have brushes and when one fails, you could get 220V power to the coach, which isn't designed for that!


First, you won't ever know for sure what caused the electrical problem. There is no easy way to determine if the outlet on a pedestal has a bad terminal or not but that's not likely. But if you look at your plug, don't just concentrate on the fried, hot terminal. Your common neutral, the one opposite the round ground terminal, is very oxidized. That will happen with an unbalanced load. The 2 hot terminals are 110V each that are 180 degrees out of phase to each other. So, one side is positive while the other negative for a differential of 220V or so. If an AC is running on one line, another AC on the other, then they're more or less balanced. But if you have 2 ACs on one line and other stuff as well, the neutral can be carrying a lot of current and it will get very hot and react with oxygen. A bad brush connection in the cord winder can do the same. The neutral line can get fried all the way into the coach's breaker box. Make sure you check on the insulation around it in there. It can also fry the contacts on the transfer switch. If you are able to, look at those and make sure they look okay. If the transfer switch fails, it will fail when you plug into the pedestal or the power outlet at home and not when you're on generator power. If that happens, you know it's the ATS. Whenever I travel, I always carry a spare transfer switch. And I ditched my cord winder.

[NeilV]

Originally Posted by mymyst

Ok some further detail here:
The yellow head in one of the pics is the female (downstream or "coach" side) plug of the Camco power defender portable surge/ems protector. The black head in the first pic is the male, or coach-side end of the 50amp cord off the power cord reel.

Hope this clears it up some!

So the outlet on the power pedestal at the campground was good but the female plug on the CamCo device failed on one lug damaging the male end of your cord reel. Sad when the device with the guarantee to protect is itself what causes the damage.

Does CamCo claim any dollar value of protection when using their device? If so they may step up and help defray the cost of repairs. How old was the CamCo device that had its female cord end fail?

[alik]

Originally Posted by mymyst

We were recently in a campground for two weeks, had to move spots twice. We were in our last spot for 5 days/four nights, campground full, hot, humid weather, everybody running full on A/C 24/7....never had any indication of ANY electrical problems, ie; low voltage, etc...and had a fairly expensive portable power manager/surge protector unit at the pedestal.

The morning of our departure I went to unhook the utilities, and noticed some discoloration around the female socket side of the surge unit. The socket was also "hot" to touch. Once I disconnected the unit from shore pedestal and the coach, I was shocked to see "arc" paths between two of the terminals on the coach cordset and the surge unit socket, and one of the legs of the coach cordset had fried the spade terminal (see pics).

Still not sure what happened to take this out, but I wound up replacing the surge unit with an even more sensitive unit, with temperature monitoring of the socket, AND the entire coach side cordset reel, all in about $2,000 to make whole, but at least no fire and only torched easy to replace components. I was surprised that RV dealers don't/won't want to replace just the cordset head or even just the cord, kind of made sense when they explained it all to me. BUT you could save a bunch if you were close to home and could find just the replacement cordset and save the power reel.

I was travelling so just bit the bullet, and smoked the credit card.

Moral of the story is, don't skimp on surge protection units, and occasionally visually and physically check your electrical connections for evidence of overloading/overheating.

Hi I’m new to all this and your story scares me. Should I always have a power surge protector between toy rig and the outlet?