Electrical Issue?

[chuck & lori]

I noticed on Friday when I unplugged my trailer from the 30 amp receptacle the one blade no longer had the brass coating and the rubber/plastic was soft and somewhat deformed-like it had melted just a little. It was not hot to the touch however. If you were looking at the plug with the wire down it is the flat blade on the left. Any guesses/ideas what might have happened?
We were camping at a CG in Erie PA. Cannot say for sure if this happened there or at Buttonwood, as I do not recall looking at the plug when I unplugged on Monday. I am sure it was not like that when we left for Buttonwood as I did look at the plug when I unplugged the 15-20 amp adaptor.
Thanks in advance for your help

[JohnB]

Hi Chuck & Lori, see if this helps.

Where you running the AC unit this past weekend? That is the highest current draw in the camper. The microwave is next unless you have something else creating "heat" plugged in or a combo of things. (fyring pan, toaster etc) And then you add the converter over head you could be pulling maybe 20 to 25 or more amps pending what else is going on. So tell us about the what was running on 120 VAC in the camper?

The plug, see this pic, I'm trying to figure out which wire (blade) you are referring to. This is a Camco after market plug I added to mine. This is viewed from the pull handle side. See the black wire. I'm assuming your orientation is that the black wire blade is the one that looked like it was hot. Please confirm if not we have other issues.



Here are my thoughts on what "might" have happened.

1. Low voltage at the CG because lots of people where using the AC units. I have one of those 120 VAC meters that plugs in all the time to watch for this in the summer. If the voltage is lower then normal the current goes up and can create some of what you are referring to. That brass is actually solid brass, not a coating and what you are seeing is heat from over current tarnishing/welding the brass.

2. A loose receptacle at the CG. If you are drawing close to full current due to the AC unit and other loads, even if the voltage is up where it is suppose to be, a loose receptacle does not make good contact and then heat comes from this. Was the plug real easy to pull out?

You talked about the 30 amp to normal 15 amp home plug adapter, did you use that this weekend at the CG when trying to run the AC unit? This can cause issues if you use one of them on too much power draw.

If your cord plug is too melted and the blade is loose, then a new plug would be a good thing to change out. You do not have to replace the entire cord, just the plug. This is hard to tell how good or bad your is in just words. If you can take it and wiggle it around real easy because the plastic melted from supporting it, that will become a problem eventually.

Hope this helps

John

[chuck & lori]

Thanks John. In your 1st pic it would be the blade attached to the black insulated wire. I do not know if it is black however as my plug is a solid unit, not like yours. I cannot see the wires within. The plug was not loose when I pulled it out at either CG. We did use both the AC and the microwave, but I do not recall using them together. No toaster or heater. Hair dryer maybe? And a curling iron as well? I'll have to check with Lori on those
I never use the AC at home when plugged to the adaptor. I have to use an extension cord, so I only use the fridge to get it cold in advance and maybe the radio (but that's 12 volt anyway, right?).
The blade looks copper, I guess that's how brass look after it has been overheated?
I like the looks of your plug, guess I will go looking for one of those. Is it RV specific, or might I find one at an electrical supply store or a Home Depot, etc.?
Again, thanks for your help.
Chuck

[JohnB]

Chuck

OK the good news. You where toasting your plug on the correct polarity.... Meaning the CG was not wired backwards.

Now to what was going on. Could still be low CG voltage. Running the AC at the same time as the Microwave is a draw. That draw gets added to the power convertor that you have no control over. Just heads up for future to watch and not try to do that. Same with the "heat" producing devices. 1 heat producing device at a time.

It is hard to back into exactly what went wrong with out knowing more on the CG and what you where running at the time. But it sounds like you where running close to full current plus some. There are situations where you can be drawing a full 30 amps and not trip the breaker and that plus a maybe not exactly perfect plug connection creates heat at the plug.

The blades of the plug are normally brass. Copper while a great conductor is not very stiff unless you get into the exotic alloys of it. It is a soft metal which is good for wire flexing but not great for stiff plug blades. If your brass one looks like copper, then it got hot.

The plug I have at Camping World:
Camco Power Grip

They are becoming more popular and can be found at most RV stores. Even some Wal-Mart’s. The grip on the handle is really good. They are a little bit of a job to wire, let me know if you do this as that is a post in itself. The only draw back is the handle sticks out some and the shore power box will not close all the way. Not a real problem, just and observation. If the grip was 1/2" narrower it would be perfect.

Hope this helps

John

[frank]

Originally Posted by JohnB

They are becoming more popular and can be found at most RV stores. Even some Wal-Mart’s.

FWIW, Walmart seems to be blowing those out now. I've been to 3 stores lately (ugh) and seen them on the clearance rack in all 3 stores for $2-3 off.

- Frank

[chuck & lori]

Thanks JohnB for your always very informative reply. We will be more careful of the items we have drawing electricity at any one time.

Frank, thanks for the Wally World tip. I will check the local ones around here before I go online.