Melting blade on surge protectors

[SteveSueMac]

It's on the blade at the 4:00 position on the black and yellow pics below. What would cause this? Here's the detailed background FYI.

I mentioned a while back that my Progressive Industries 30A external unit had some melting on one of the blades at the pedestal. It had shut off 5 times in the first couple hours. The campground claimed the pedestal was new (it looked brand new to me) and he tested the pedestal with a volt meter and everything seemed fine. He said the problem was with the unit not being able to lay flat against the pedestal which caused a poor fit which would have caused "arcing" and the melting and would have shut off the Progressive like a fault. See pic below (black plug). The only fault code on the Progressive was for low voltage.

So I ran to the nearest RV place and bought the only alternative they had in the shop - a Camco version which I don't like or trust nearly as much as the Progressive. I used it the rest of that weekend - bungee corded tightly to the post. It only shut off once the rest of the weekend (AC on a lot) which I attributed to a low voltage condition in the park (this unit has no codes to tell you why it shut off - and I failed to check the plug on the Camco at the end of that weekend so I don't know if it was damaged then).

This weekend, I was using the Camco - no power problems - and it laid perfectly flat against the pedestal - though I bungeed it to the pedestal anyway. When I was packing up, I noticed the same blade had melted some. See pic below (yellow plug).

My grey power cord for the trailer (which plugs in to these units that then plug in to the pedestal) has no such damage (see pic below - grey plug).

Is there something wrong with my AC that's causing this melting? At $300 a pop, these surge protectors are no longer feeling like "cheap insurance" and before buying another, I'm wondering if I have something wrong with my trailer?

Wide open to your thoughts! Thanks.

[perryg114]

I have had similar issues when daisy chaining an extension chord with the pigtail. The extension cord had a lip around it that kept the two plugs from fully engaging. When I cut the lip off the extension chord I did not have as many problems. At home I use a twist lock connector to connect the trailer to shore power and those don't have as many issues at the three prong plugs. My camping pig tail has the 30A camper plug on one end and the twist lock on the other. The twist lock end has never caused problems. If the plug does not seat all the way, it will get hot like yours did. Sometimes they get hot anyway if there is a poor fit. When the pins get corroded it is best to sand them back to the brass. Brass oxide does not conduct as I found out as a kid playing with HO trains.

Perry

[wahoonc]

Basic cause is a lot of current flowing across a single conductor. There is probably a poor fit between the female and male connectors. Twist locks are susceptible to it too when maximum current is run through them for hours on end.

Aaron

[SteveSueMac]

I thought I was solving for poor fit by using the bungee cord. Would that clear grease (dialectic ?? ) used on a 7-pin connector be of any help to improve the connection?

As to the point about a constant flow of electricity - is there something I'm missing about that? Are these systems designed to handle the load or is running the AC too taxing? This summer has been pretty good in the northeast so far but sometimes it's hot and humid and that's what the AC is for. I had no problems with this last year and on some trips ran the AC much longer and at lower temps than either of these examples.

I guess I should also ask how common this experience is with others on the forum.

Thanks!!

[mistermcfrug]

Does your unit look like this:

Amazon.com: Progressive Industries PT30C 30 Amp Portable Electrical Management System: Automotive


I have one just like the one in the link that basically melted in hot weather in the summer at Zion Nat. Park. I know the A/C was working full blast 24/7. I did find Progressive to be very easy to do business with. They quickly gave me a new unit. So, DO NOT BUY A NEW ONE! Mine was maybe 5-6 years old when they replaced it.

[perryg114]

I expect you will find this on many RV pigtails. No reason you can't use one that got hot if you clean the oxide off of the blades. If there are screws on the back side and one is loose it will overheat. As long as the blade does not come loose from the wire you should be fine with one that got hot. Keeping the blades clean will go a long way towards lowering resistance and the heat it produces.

Perry

[cwf]

New pedestal does not mean a GOOD one.

We had a bad one which I could tell did not "seat" well.

Trust no pedestal.

[SteveSueMac]

Originally Posted by mistermcfrug

Does your unit look like this:

Amazon.com: Progressive Industries PT30C 30 Amp Portable Electrical Management System: Automotive

I have one just like the one in the link that basically melted in hot weather in the summer at Zion Nat. Park. I know the A/C was working full blast 24/7. I did find Progressive to be very easy to do business with. They quickly gave me a new unit. So, DO NOT BUY A NEW ONE! Mine was maybe 5-6 years old when they replaced it.

Yes that's the unit. I'll call them. Thanks.

[SteveSueMac]

Originally Posted by perryg114

I expect you will find this on many RV pigtails. No reason you can't use one that got hot if you clean the oxide off of the blades. If there are screws on the back side and one is loose it will overheat. As long as the blade does not come loose from the wire you should be fine with one that got hot. Keeping the blades clean will go a long way towards lowering resistance and the heat it produces.

Perry

Thanks - the Progressive doesn't look as bad as the Camco. I'll sand down the blade for this week and will call the manufacturer.

[richinny]

you might want to check the connection on the wire that goes from the trailer breaker panel to the connector. some have reported loose connections at the connector.

[wahoonc]

Originally Posted by SteveSueMac

I thought I was solving for poor fit by using the bungee cord. Would that clear grease (dialectic ?? ) used on a 7-pin connector be of any help to improve the connection?

As to the point about a constant flow of electricity - is there something I'm missing about that? Are these systems designed to handle the load or is running the AC too taxing? This summer has been pretty good in the northeast so far but sometimes it's hot and humid and that's what the AC is for. I had no problems with this last year and on some trips ran the AC much longer and at lower temps than either of these examples.

I guess I should also ask how common this experience is with others on the forum.

Thanks!!

A/C is high draw, running it constantly along with everything elses puts maximum load on your plug. We have several pieces of equipment at work that are high draw some are 110v, others 220v, the results are the same, eventually the plugs have to be replaced due to melting.

I can't prove it but I suspect the plugs have a "duty rating" and it isn't 100%.

Aaron