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Chickenman · 07-12-2012, 04:28 PM

Lost power while in a park in Wilmington NC last Sunday night. The shore power cord shorted out and melted the surge guard female plug. I was unsuccessful attaching photos so I opted for a link to the album with the results of the power problem.

Purchased a new 30 amp cord the next morning and all systems on board worked as usual.

What do you think caused this?

What is solution for the future?

Thanks in advance for any advice.

https://plus.google.com/photos/10425...CLubvfDmwvqPYQ

RickO · 07-12-2012, 04:35 PM

Ouch.

Actually, from what I've read here, it's not that unusual for the plugs on 30 amp connections to overheat and melt when the current draw is near maximum for extended periods. I dropped off my coach for repairs yesterday and while browsing through their accessory area I noticed they had quite a stock of these replacement plugs.

I'm sure some of our technical gurus will be along soon with input.

Glad you got everything back in order.

Rick

Skip426 · 07-12-2012, 06:16 PM

X2, on RickO's reply, poor/dirty/loose contact and heavy draw =

ChasA · 07-12-2012, 06:39 PM

My bet is on a loose screw inside the yellow plug. It is a replacement male plug that relies on screws to hold the wires in place. the screws have a tendency to loosen with repeated heating and cooling. When they get loose enough, they start arcing and generate enough heat to melt everything. If you're going to replace the male plug, make sure to tighten the screws well and periodically take the thing apart and re-tighten or use lock washers and crimp-on eye terminals.

Gary RVRoamer · 07-13-2012, 02:18 PM

A loose connection or broken wire inside the yellow plug, which is a replacement for the original anyway. It's a fairly common failure, especially if the plug replacement was done by an amateur. The current path is "choked' at that point and gets very hot, melting anything in contact with it.

Replace the plug and make very sure the connection is made solidly and the screws very tight. It would be prudent to remove and inspect occasionally as well.

Luckiest Dreamer · 07-13-2012, 04:24 PM

Low power from the RV park will fry a plug quickly. With a 30A service we always carried a tester available at most RV Parts dept's. They have saved me many times in the past.

Chickenman · 07-27-2012, 07:09 PM

Thank you all for you input.

bdickson · 07-27-2012, 07:20 PM

Quote:

Originally Posted by Luckiest Dre

Low power from the RV park will fry a plug quickly. With a 30A service we always carried a tester available at most RV Parts dept's. They have saved me many times in the past.

I use a tester on the pedestal before I plug in. It will detect low or high voltage and frequency as well as polarity reversal and open ground. I have another of the same tester permanently plugged inside the MH where I can hear the alarm if anything changes. Then I have a hard wired surge suppressor and a voltage regulator. Reason for all this belt and suspenders? My previous MH almost caught fire due to low (90 volt) power from the campground pedestal when I was running ceramic space heaters in the winter. Fortunately we caught the smell of smouldering cable before the fire burst out.

Jim_HiTek · 07-28-2012, 12:34 PM

Take a look at those blades on your bad power head. See how they are just flat pieces of stamped metal? Many manufacturers use them because they are cheap, cheap, cheap. With repeated insertions and extractions of that head into/out of the plug (female plug in) you flatten out the mating spring contacts in the female. Causing a poor connection, higher resistance and heat. This also is a concern in RV parks...think of the thousands of times people have inserted and removed their cords using those outlets.

When you're out looking for new, try to find the style of male connectors that are folded over, which creates a slot you can periodically push a blade into to expand them. That type is more appropriate for RV'ers then the flat blade is. When you're looking for the female end, look for contacts that have two sides and are nearly CLOSED...the cheap ones there's already a large gap there.

All of the offerings in many stores (such as Camping World) are the stamped single piece contact but I believe Home depot has the folded blade type, or at least they use to.

Cat320 · 07-29-2012, 05:57 PM

Quote:

Originally Posted by Gary RVRoamer

...A loose connection or broken wire inside the yellow plug...

That's what happened to us on a 5th wheel 50 amp plug. The neutral came loose and married up with one of the hots...we had 180 on one side and 60 on the other. Not good.