Melting power plugs

[johns928]

I use a small amount of dielectric grease on my plug and as others have suggested, plug it in and remove it a couple times to spread the grease and clean the connections prior to turning on the breaker, Dielectric grease is an isnsulator rather than a conductor so won't cause any short circuits but does a good job of preparing the connectors and making it easier to connect and disconnect.

[NXR]

Originally Posted by MechEngrSGH

Lots of misconceptions about circuit breakers, how they work, what the protect and HOW THEY TRIP. Trying to draw the maximum from a 30A connection (continuously) is a prime reason for 'succeeding' to operate on small overloads that do some of this kind of damage (but not always necessary). You probably assume that a breaker is a perfect device and will prevent you from getting into trouble as you keep pushing the limits. THEY LIKELY WON'T.

...

You missed one.

That circuit protective devices such as fuses and breakers are NOT intended to protect the load, the thing being powered, from damage. They are designed to protect the power source from a defective load.

Also, due to how series circuits work, the current flow in all portions is the same. A power cord is just a simple two-wire series circuit. In order for that 50 amp breaker to trip or that 50 amp fuse to blow, the full 50 amps has already coursed through the device or whatever is connected to the wires.

The circuit protective device does not stop an overload through the device. It just limits the duration, hopefully.

Ray

[sibe]

This would be an odd fix or work around..for 30A users
At the campground if you have a pedestal with a 50A receptacle , get an adapter to 30A a good one and try that, it may fit better or even if the 50A recpt is a bit older your total amp draw is still <30A on a 50 amp .. GRANTED Your cord is not protected fully at pedestal but RV is with its 30A main..

Just suggesting,, not a fix but if toy are in place, it is Saturday of a 5-7 day stay, it is HOT, need AC etc.. You can maybe get buy with this,,

The read from the NEC about a cord being 80% is gospal .. then if the blades are loose,, you just dropped another notch of power off..

the dielectric grease on plugs,, IMO don't it is not its real purpose.. Hit the plug with wd40 will dispel moisture, allow it to cleanly slide in, with no gunk build up from a grease,, dust and crap will stick and clog up the grease over time..

[dkperez]

Unfortunately, the old receptacle was really bad and it got thrown out back when I originally planned to replace the receptacle. So there's nothing to test.


I sent an email to what MAY be the manufacturer, but haven't heard anything.


As for using a 50A plug - I've done that when necessary, and what that does is melt the 30A side of the adapter, and weld the plug from the trailer to it.

[NXR]

Originally Posted by dkperez

As for using a 50A plug - I've done that when necessary, and what that does is melt the 30A side of the adapter, and weld the plug from the trailer to it.

Then you have other problems and need to engage a qualified electrician. You're at risk of an electrical fire or worse.

Ray

[UP2LATE]

We have a 50 amp RV. On the last trip we stayed at a series of campgrounds with 30 amp service. I use a 50 to 30 amp dogbone. The EMS (Energy Management System) in the RV usually does a great job at keeping us under 30 when it detects 30 amps. At this one 30 amp park the power would shutdown and pedestal breaker would pop. The surge protector was registering low voltage from time to time. Went out to the pedestal and felt a warm dogbone. Ran a 50 amp extension to another site with the same results. Concluded that low voltage in the park was the problem. This was the wrong conclusion.

The 30 amp parks after that had the same problem. Was beginning to think the whole region was wired wrong. At one campground they came out and replaced the breaker, outlet and box (it was an old unit that needed to be replaced anyway). Still had the same problem. Finally I looked at the warm dogbone and saw black circles around the pins at the base. Looks like the dogbone had been fried at the first 30 amp campsite. Bought a new dogbone at the camp store and everything worked fine. Turns out that a bad outlet at the first 30 amp park burned up the dogbone. Had no idea that dogbones could go bad.

Now I keep two 50 to 30 amp dogbones. One is for normal use. The other is a backup in case the first one burns up.

[Steve 716]

First, the 34830 monitors for surges but not much else according to the spec sheet. The 34830 is not listed on the Southwire web site. There are a lot of things that can go wrong at a pedestal that this device doesn’t monitor for. My recommendation would be to replace it with a more comprehensive protection device.

Second, what are you using for an extension cable? The ones sold by hardware supply stores like Home Depot or Lowes do not have the specs or sufficient shielding that a true RV power cable would have. This can cause heat and intrusion.

Third, if the cable to plug wire connections inside the plugs are not properly made you are going to have heat and eventually maybe a short circuit within the plug. The cable and/or plug you are using could be causing the melting.

When I decided to install an internal surge suppressor in my coach I purchased a quality 50 amp round RV extension cable. You would buy a 30 amp cable. I cut off one end long enough to use in my internal installation wiring and installed a new RV plug on the end of my remaining extension cable. This left me with enough cable for a shorter extension. I made sure to use both RV cable and a quality plug in constructing this extension. I have never had any issues using this rebuilt extension cable.

In summary (1) consider upgrading to a higher quality external pedestal mounted surge suppressor that adds monitors more faults than just surge. My preference is for Progressive Industries devices but Surge Guard will certainly work, (2) use only RV approved power cables, and (3) use only RV approved plugs and receptacles. This should solve your problems.

[dkperez]

I got a quick answer from the company that makes the Surge Guard. The blue wire is a thermocouple lead that's buried in the receptacle. If the pug gets hot it's supposed to shut off the power...


Clearly, since the molded plug was melted into a pile of slag with the plug from the trailer welded into it, the thermocouple DIDN'T work...


Guy said the protector will work fine without the thermocouple.

[MechEngrSGH]

Originally Posted by NXR

You missed one.

That circuit protective devices such as fuses and breakers are NOT intended to protect the load, the thing being powered, from damage. They are designed to protect the power source from a defective load.


Ray

Ray,
You have hit on another misunderstanding. OCPD is designed to protect the (branch) WIRING as it is the weakest link in the system. Neither the load nor the source are protective targets. By protecting the weakest link, the wiring, from a fault in the load, you DO ACTUALLY protect the (more robust) source as well but most sources are more capable of resting the failure of any individual branch circuit.

Think of it another way, If there were no OCPD, and the wire between source and point of use overheated to failure, that too would (likely) protect the source from an overload (but with a much higher current 'fuse') but not the system. The failure of the wire in that mode would at least render the system inoperable and more likely, cause a fire (which could potentially destroy everything including the load and source). OCPD are meant to maintain the operational integrity of power distribution system (you are correct, NOT the load).

You are correct that a defective load is the most common cause but wiring shorts are also a major cause for OCPD activation...... This leads directly into the two causes of activation and how/why to design for each.... 1) Protect against an overload and 2) protect against a fault (short). There are different criteria and reasons for both. This is more of an issue outside our scope of discussion.

[dkperez]

Wow, this topic has been interesting.


I thought the issue was rare and probably overblown like some other RV things that people get excited about. Apparently it's a real and ongoing problem. One I suspect the sale of about 84 gazillion new RVs during Covid, that are now clogging every campground and RV park in the country, is making worse.


As far as I know, both my cable from the RV and the extension are good and of reasonable quality.



I'll have to look at some of the more capable protectors.

[NXR]

Originally Posted by MechEngrSGH

You have hit on another misunderstanding. OCPD is designed to protect the (branch) WIRING as it is the weakest link in the system. Neither the load nor the source are protective targets.

You might be splitting hairs now. I did not think for a moment that the 15 amp breaker in my basement protected the neighborhood transformer in the backyard or the true source, the nuke plant on the lake.

The "source" of the power feeding the breaker is what I meant.

Ray

[rarebear.nm]

Originally Posted by Fumes21

So can you use Die-electric grease on the prongs for a better connection?

I use NO-OX-ID instead of die-electric grease. Die-electric grease is a lubricant and an electrical insulator. Look it up on the web if you like.
NO-OX-ID has been used in the power and telecommunications industries for about 65 years. It will lubricate the connection and is electrically conducting unlike die-electric grease. It also reduces oxidation and corrosion in connections. A very small dab will do it and last a long time.

[MechEngrSGH]

Originally Posted by rarebear.nm

I use NO-OX-ID instead of die-electric grease. Die-electric grease is a lubricant and an electrical insulator. Look it up on the web if you like.
NO-OX-ID has been used in the power and telecommunications industries for about 65 years. It will lubricate the connection and is electrically conducting unlike die-electric grease. It also reduces oxidation and corrosion in connections. A very small dab will do it and last a long time.

Absolutely correct. I don't think people understand that 'dielectric' means INSULATING. For some reason, everything silicone is assumed to be good/beneficial. Putting an insulator on contacts interferes with conductivity so the opposite, REMOVING insulation in the form of metal oxides is exactly the right thing. A little goes a long way.

https://www.amazon.com/NO-OX-ID-Spec...85242409&psc=1

[tropical36]

Originally Posted by UP2LATE

We have a 50 amp RV. On the last trip we stayed at a series of campgrounds with 30 amp service. I use a 50 to 30 amp dogbone. The EMS (Energy Management System) in the RV usually does a great job at keeping us under 30 when it detects 30 amps. At this one 30 amp park the power would shutdown and pedestal breaker would pop. The surge protector was registering low voltage from time to time. Went out to the pedestal and felt a warm dogbone. Ran a 50 amp extension to another site with the same results. Concluded that low voltage in the park was the problem. This was the wrong conclusion.

The 30 amp parks after that had the same problem. Was beginning to think the whole region was wired wrong. At one campground they came out and replaced the breaker, outlet and box (it was an old unit that needed to be replaced anyway). Still had the same problem. Finally I looked at the warm dogbone and saw black circles around the pins at the base. Looks like the dogbone had been fried at the first 30 amp campsite. Bought a new dogbone at the camp store and everything worked fine. Turns out that a bad outlet at the first 30 amp park burned up the dogbone. Had no idea that dogbones could go bad.

Now I keep two 50 to 30 amp dogbones. One is for normal use. The other is a backup in case the first one burns up.

I fail to understand why you and others keep fighting it with Band-Aid fixes when all you have to do is to install a 50amp plug in place of the 30 and be done with it. Now the only dog-bone that you need to carry is for only having a 30amp outlet available on occasion. Well maybe a 15-20amp as well, for a just in case situation and one that you should have anyway.