Community Forums

danleininger · 08-06-2018, 12:56 PM

I have noticed my 50 Amp plug gets quite warm. Currently, i’m running no more than 20 amps on both legs. I measured the temperature difference between the ambient temp and the plug and the plug is 20 degrees warmer than the temp around the plug (exterior of the coach parked in my garage = 86 and the is plug 107 degrees.) So my question is how warm is too warm?

Any electricians or EEs out there?

I have purchased a replacement plug but using it will eliiminate the waterproofness of the plug.

Thanks in advance!

Finance · 08-06-2018, 01:05 PM

Loose connections or too small a cross section in a conductor generate heat. Most frequent cause is a loose female connector in these cases. Check the receptacle.

BFlinn181 · 08-06-2018, 01:05 PM

Have you tried cleaning the blades of the plug? A bit of dirt or corrosion could build up resistance. 20 amps per leg shouldn't cause a temperature rise. It will be interesting to see if the new plug reduces the temperature rise. A good replacement plug should be waterproof, if not you could use some sealant around the cord at the plug to increase water resistance. Most every pedestal has a lift up cover and the orientation of the plug should also shed water so I don't think it will be an issue.

xrated · 08-06-2018, 01:19 PM

Assuming it is the factory plug/cordset you are referring to, it should be 6ga wire.....make sure that it is. And as stated in some previous posts, 20 amps should not be causing that kind of heat to build up. Look for loose connections on every single one of the wires, both at the plug if accessible and at the recept. Also, as stated, make sure the blades are shiny clean....no oxidation on them AND make sure that the plug is a very snug fit into the recept. Any one of the above can cause the excessive heat you are experiencing.....more than one of them can cause even more heat. Let us know what you find.

WoodyS · 08-06-2018, 04:14 PM

Quote:

Originally Posted by danleininger

I have purchased a replacement plug but using it will eliiminate the waterproofness of the plug.

Why would replacing the plug eliminate waterproofness? In general, the plugs on RV power cables aren't really waterproof anyway. And that's why the marine versions use a rubber boot over the plug that compresses over the pedestal fitting. In my experience, most RV park pedestals aren't threaded for the waterproof marine boots.

Marine waterproof boots are an add-on option and you can buy them separately. I got mine at West Marine. Once you chop the old connector off, you slip on the boot (it's a tight fit around the power cable for obvious reasons), and then install the new plug.

When you encounter a RV park that has power pedestals threaded for the waterproof boot, just slide the boot up and tighten the collar. For pedestals that aren't threaded, just slide the boot down a few inches and ignore it.

Warning, the waterproof boots aren't cheap! And neither are the plugs. When the 50 amp plug on my 5th Wheel trailer pitted and failed, I think the replacement with boot was something like $120 -- PARTS ONLY! Good 50 amp plugs and boots aren't cheap.

I agree with all the previous posts regarding loose and "dirty" connections. Either of those will heat things up quickly -- and either pit the brass connections or melt the rubber parts.

Can you see any pitting on the male blades? Pitting is a sure sign of excess resistance from a bad connection.

Craig36 · 08-06-2018, 04:22 PM

The terms hot and warm are subjective.

If it becomes too hot to touch or you smell rubber/plastic melting...then you have a problem. Mine gets warm if I run both AC units. If there is a short in your system, the circuit breaker will trip.

BFlinn181 · 08-06-2018, 05:06 PM

Quote:

Originally Posted by Craig36

The terms hot and warm are subjective.

If it becomes too hot to touch or you smell rubber/plastic melting...then you have a problem. Mine gets warm if I run both AC units. If there is a short in your system, the circuit breaker will trip.

But a plug that heats up at only 40% capacity of the 50a limit speaks to either a dirty plug or internal resistance. No one said there was a short, but heat in an electrical circuit is caused by resistance. Waiting for a circuit breaker to trip is not wise practice, cleaning the prongs and making sure all connections are tight and unfrayed is.

Webz · 08-06-2018, 05:13 PM

I had the same problem. Ended up changing the plug. Here is a link to the thread:
http://www.irv2.com/forums/f103/shor...ot-392176.html

fla tom · 08-06-2018, 05:17 PM

Check the tightness in the transfer case.

BFlinn181 · 08-06-2018, 05:31 PM

Quote:

Originally Posted by fla tom

Check the tightness in the transfer case.

A loose connection in the transfer case would cause resistance at that point and would not create heat at the plug.

Dutch Star Don · 08-06-2018, 07:50 PM

Dan.....as a good practice, every other year or so, open up the transfer switch box and surge protector box (if you have one) and really lean on the four big wire clamps from the power cord.

When you're done, go inside to the circuit breaker panel, pull the cover and tighten all the screw hold downs there, especially the grounds.

Make sure the connections inside your home outlet are tight and ten check your plug again.

nothermark · 08-06-2018, 08:12 PM

Before I cut off the plug I would try another socket. The problem is probably a loose fit. What is loose is the question. If the problem tracks the plug then it's plug time. If it is only that socket then the new plug won't fix anything.

Solo_RV_Guy · 08-06-2018, 08:25 PM

Quote:

Originally Posted by nothermark

Before I cut off the plug I would try another socket. The problem is probably a loose fit. What is loose is the question. If the problem tracks the plug then it's plug time. If it is only that socket then the new plug won't fix anything.

In addition to your good advice, it's possible that a wire to the outlet (inside the pedestal) is loose, causing heat to transfer to the RV plug.

To the OP - if you unplug, is one pin on the plug hotter than the others?

Winemaker2 · 08-13-2018, 04:14 AM

Quote:

Originally Posted by nothermark

Before I cut off the plug I would try another socket. The problem is probably a loose fit. What is loose is the question. If the problem tracks the plug then it's plug time. If it is only that socket then the new plug won't fix anything.

Agree
I'm assuming the cord end plug is molded and not just clamped on the cord end and that's the waterproof feature you mentioned.
I would try to eliminate other sources of the problem before cutting and replacing the plug.
If lose fit I'm thinking it's the recepticle and would opt to replace that before the cord end.