melting plug

[dustinl]

in the past 14 months i have had to replace the 30A plug that plugs into the rv parks box at least 3 times because 1 of the prongs overheats and melts my plug. need ideas on what might be the cause

[Lynnmor]

ScottG wrote:
It's sad but the industry's NEMA TT30R/P design is really under engineered IMHO. Many decades ago when it was created, there were no electric water heaters (in RV's) or micros, TV's, large battery chargers, etc. Just some lights and the occasional space heater. Then add in poor quality, off shore parts and it only gets worse.
We use a lot more of the capacity if these "trailer" circuits now and while they work OK when everything is perfect, they don't like running a constant load at anywhere close to their 30A rating.
It's too bad we can't switch over to the marine undustrys 30A receptacle for pedestals. It seems to hold up better.

If you watch when people plug in and unplug, almost always the breaker is not turned off. It doesn't matter what kind of receptacle is used, none will escape damage from this kind of abuse. I always plug in multiple times to wipe the contacts and also use a sacrificial plug to save the power cord end.

[ScottG]

It's sad but the industry's NEMA TT30R/P design is really under engineered IMHO. Many decades ago when it was created, there were no electric water heaters (in RV's) or micros, TV's, large battery chargers, etc. Just some lights and the occasional space heater. Then add in poor quality, off shore parts and it only gets worse.
We use a lot more of the capacity if these "trailer" circuits now and while they work OK when everything is perfect, they don't like running a constant load at anywhere close to their 30A rating.
It's too bad we can't switch over to the marine undustrys 30A receptacle for pedestals. It seems to hold up better.

[rhagfo]

dustinl wrote:
in the past 14 months i have had to replace the 30A plug that plugs into the rv parks box at least 3 times because 1 of the prongs overheats and melts my plug. need ideas on what might be the cause

OP has not been back in like 8 days, if same park, bad pedestal outlet. Different parks likely too much draw.

[importman]

If it's the same pedestal plug I agree with Flute and cavie. I've seen the same thing with automotive headlamp plugs. You notice the terminals on the headlamp bulb are burned so you get a new bulb. But the female part that the terminal goes into is burned just as badly. If you don't replace both parts it just repeats the damage over and over.

[Me_Again]

smarty wrote:
Have you checked the rig itself to see if it is "Hot"? You may have some sort of short that is drawing excessive power.

Excessive power trips circuit breakers. Bad/worn out receptacles on power pedestals causes power cord ends plugged into them to over heat and burn up.

[smarty]

Have you checked the rig itself to see if it is "Hot"? You may have some sort of short that is drawing excessive power.

[Campinghoss]

Yep, the problem is in the cg's receptacle. If the contacts in the receptacle are not making good contact on both sides of each of the male prongs it is generating heat and will cause the problem. Sometimes folks will tell you to bend the male prongs out so it will fit tighter in the receptacle. That is totaling incorrect and will just compound the problem.

[larry_cad]

MNRon wrote:
Question for those wiser than me: If plug is melting (I assume he means one of the electrodes in the plug) that is evidence of too much heat at that point. That heat is caused by current and resistance, right?

IF the electrode has a solid connection into the socket why would a loose connection downstream cause that contact point to overheat? A short downstream would trip a breaker before current got crazy. A loose connection could cause lots of current spikes, potentially too short to trip a breaker, but I would expect the arcing (and associated heating/melting) to be at the point of the loose connection. If the plug electrode were solidly connected to the receptacle I wouldn’t think it would be a point of excessive heating.

With all that said, a plug connection will have some resistance but I would expect that to be much smaller than the resistance of the downstream intermittent connection. So again that is where I would expect arcing and melting.

Long way to say I think that if he’s having melting of his plug electrode, I would be looking for reasons it wasn’t making a solid connection and result in arcing there, not be looking first for downstream issues.

What am I missing?

Thank you. This is so obvious I was wondering if it was worth stating and you beat me to it. Some of the previous suggestions were so far out I am amazed! And yes, I agree the problem is at the plug and CG receptacle, not in the OP breaker panel, etc. Hopefully the OP can discern the wheat from the chaff.

[Lynnmor]

Flute Man wrote:
Sounds like the park needs to replace or repair the socket in their pedestal. Poor connections cause heat.

This is the correct answer and it was the very first reply.

[MNRon]

Question for those wiser than me: If plug is melting (I assume he means one of the electrodes in the plug) that is evidence of too much heat at that point. That heat is caused by current and resistance, right?

IF the electrode has a solid connection into the socket why would a loose connection downstream cause that contact point to overheat? A short downstream would trip a breaker before current got crazy. A loose connection could cause lots of current spikes, potentially too short to trip a breaker, but I would expect the arcing (and associated heating/melting) to be at the point of the loose connection. If the plug electrode were solidly connected to the receptacle I wouldn’t think it would be a point of excessive heating.

With all that said, a plug connection will have some resistance but I would expect that to be much smaller than the resistance of the downstream intermittent connection. So again that is where I would expect arcing and melting.

Long way to say I think that if he’s having melting of his plug electrode, I would be looking for reasons it wasn’t making a solid connection and result in arcing there, not be looking first for downstream issues.

What am I missing?

[enblethen]

Not only cut back wire, but apply good coating of de-oxidation compound on wire connection points.

[ksg5000]

Also - when you replace the plug are you making sure you cut back the wire so that you eliminate any of the damaged/brittle wire?

[Old-Biscuit]

WOW......three times melted plug

Problem is NOT at the power pedestal it is in your power cord OR Main Power Panel

Need to go thru the wire connections in Main Panel and TIGHTEN them UP
Might even find 'evidence' of overheating at connections

Hot wire to Main CB (Black)
Ground wire to terminal strip (Green)
NEUTRAL wire connedction (which is most likely loose) (White)

[Dave_H_M]

Dustin, are you referring to the same RV park plug or is this happening at more than one park?

[Janss]

I had my plug melt once. Turned out that the cord connection at the other end, IN my motorhome was loose. There were 2 loose screws causing the wires to not make solid connections. Causes a lot of heat. I noticed my whole cord was quite warm too.