Power cable connection melting

turbojimmy · 08-22-2021, 08:09 AM

I have my camper plugged in 24x7 when parked at home. I keep the A/C on to act as a dehumidifier. I originally had a 75-ft 12-gauge extension cord plugged into the RV's power cord. It would get warmer than I'd like on the ends and voltage would drop to under 100 by the time it got to the outlets in the rig.

So I bought a new 50-foot 10-gauge cord. Voltage is good now. The new cord has 3 outlets at the end. I was using the middle one and it literally melted the 30A adapter and the outlet at the end of the cord. So I've been using the second outlet and a new adapter. It did the same thing last night before tripping the GFCI. It's a clear connector and I can see it's burned up inside. So I have one good outlet left on it. I may cut it off and install a single.

Stupid question, but would the plug getting wet cause this? I have a traffic cone sitting on top of it so it's not totally exposed to the elements. Do I need to protect it better? The common denominator does seem to be rain.

NH_Bulldog · 08-22-2021, 09:27 AM

You are trying to pull too many amps through too small of a cord. The longer the run, the bigger the wire you need. Personally I wouldn’t go more than 50 ft with a 10 ga cord while running a high amp draw appliance like the AC unit (35 ft is within my comfort zone). For that distance, you should be running 8 ga, and preferably hard wired with solid wire not stranded wire. It can be quite expensive.

As an alternative, why not just run a portable dehumidifier with a drain hose out a window or into the tub or shower drain? It is WAY less expensive, WAY more efficient, and would allow you to use a lighter gauge cord.

turbojimmy · 08-22-2021, 09:50 AM

Well that's just it. The 75-foot, 12-gauge cord didn't melt at the ends but the voltage was too low so I was concerned about the A/C (I've read low voltage can kill them).

So I got the voltage where I want it using the 50-foot, 10-gauge cord but the plug is now getting hot enough where it connects to the RV power cord that it's melted it twice. I'm wondering if it's whatever wiring they use for the triple-outlet that's causing the problem. I may hack that off and put a suitable, single plug on it. I'm down to just one useable outlet anyway. The problem is that it's the perfect length right now. Losing even a few inches is going to be a bit of an issue.

jasin1 · 08-22-2021, 10:34 AM

Your really trying to do too much with too little…you may start a fire or ruin the compressor in the ac unit.. your
Looking at voltage while system is idle…when the ac starts up it draws starting amps and your overtaxing the outlet and the cord..what is the receptacle rated for …20 amps? Is it dedicated?
Contrary to what you may hear it is not ok to run an ac unit off a long extension cord..the extension cord scenario is best if you want to have lights or keep the battery’s charged while the unit is in storage

The cord is trying to send you a message by melting it’s saying “ please stop”..

There really is no way to shortcut electrical wiring..it’s either safe or it’s not

**flybouy** · 08-22-2021, 10:39 AM

You are drawing too many amp for the wire, period. The 15 amp plug is the weakest link so it is overheating. That's why it's rated at 15 amps, not 17, not 20, not 30. Continue with that set up and you will ruin your a/c if you don’t burn down your house and trailer first. Hire an electrician to run a proper wire and outlet for the camper or stop running the a/c. You spend all that money on a camper it would be a shame to see it go up in smoke.

turbojimmy · 08-22-2021, 11:05 AM

Quote:

Originally Posted by flybouy

You are drawing too many amp for the wire, period. The 15 amp plug is the weakest link so it is overheating. That's why it's rated at 15 amps, not 17, not 20, not 30. Continue with that set up and you will ruin your a/c if you don’t burn down your house and trailer first. Hire an electrician to run a proper wire and outlet for the camper or stop running the a/c. You spend all that money on a camper it would be a shame to see it go up in smoke.

Thanks!

It's a 20 amp circuit dedicated to the RV, installed by an electrician. I don't need the full 30 amps to just run the A/C. I had my 30A motorhome plugged in for the past 5 years running the A/C without a problem other than the low voltage (which I get is the result of the long run and big draw). As I said the cord would get warm, but never "hot" and never melted. But I got a bigger gauge cord to solve the voltage issue. I could hear the difference in the A/C compressor and fan, and it tests at 110V vs. 95V with the old cord.

The motorhome melted the new cord's outlet it and now the Bullet has as well. I never had any trouble before I switched extension cords, hence my question. The new cord is a 20A, 10-gauge cord, the old was a 20A 12-gauge cord. It's getting hot at the 30A/20A adapter where it plugs into the new cord - nowhere else. Not where it's plugged into the house, the RV cord or anywhere along the run between my breakers and the outlet.

Also, playing things back in my head now, I had no issue plugging the RV into the house using a 25-foot extension 30A (TT-30P/TT-30R) cord and 30A/20A adapter at the house outlet. I had to move the Bullet a bit farther away and use the new 10-gauge cord to get to it. I now suspect that tri-tap a bit more, or the cord itself.

I ordered a new 30A TT-30R outlet for the 10-gauge cord so I can eliminate the tri-tap. That's the only thing that's different (other than the larger gauge wire which should help not hurt). I figure that way I eliminate whatever resistance the tri-tap and 30A/20A adapter introduces.

jasin1 · 08-22-2021, 11:12 AM

Quote:

Originally Posted by turbojimmy

Thanks!

It's a 20 amp circuit dedicated to the RV, installed by an electrician. I don't need the full 30 amps to just run the A/C. I had my 30A motorhome plugged in for the past 5 years running the A/C without a problem other than the low voltage (which I get is the result of the long run and big draw). As I said the cord would get warm, but never "hot" and never melted. But I got a bigger gauge cord to solve the voltage issue. I could hear the difference in the A/C compressor and fan, and it tests at 110V vs. 95V with the old cord.

The motorhome melted the new cord's outlet it and now the Bullet has as well. I never had any trouble before I switched extension cords, hence my question. The new cord is a 20A, 10-gauge cord, the old was a 20A 12-gauge cord. It's getting hot at the 30A/20A adapter where it plugs into the new cord - nowhere else. Not where it's plugged into the house, the RV cord or anywhere along the run between my breakers and the outlet.

Also, playing things back in my head now, I had no issue plugging the RV into the house using a 25-foot extension 30A (TT-30P/TT-30R) cord and 30A/20A adapter at the house outlet. I had to move the Bullet a bit farther away and use the new 10-gauge cord to get to it. I now suspect that tri-tap a bit more, or the cord itself.

I ordered a new 30A TT-30R outlet for the 10-gauge cord so I can eliminate the tri-tap. That's the only thing that's different (other than the larger gauge wire which should help not hurt). I figure that way I eliminate whatever resistance the tri-tap and 30A/20A adapter introduces.

I’d put all the money towards a dedicated 30 amp pedestal outlet…dig a trench and do the backbreaking work and have an electrician wire it up ..leave the trench open for the electrician so he can verify it’s done to code…pull the wire to the panel location and have all the material at the job..

That extension cord laying in the sun 24/7 will breakdown and cause problems before long..not to mention moving it constantly to cut grass and the ends corroding

But good luck it sounds like your mind is made up so I wish you the best

turbojimmy · 08-22-2021, 11:27 AM

Quote:

Originally Posted by jasin1

I’d put all the money towards a dedicated 30 amp pedestal outlet…dig a trench and do the backbreaking work and have an electrician wire it up ..leave the trench open for the electrician so he can verify it’s done to code…pull the wire to the panel location and have all the material at the job..

That extension cord laying in the sun 24/7 will breakdown and cause problems before long..not to mention moving it constantly to cut grass and the ends corroding

But good luck it sounds like your mind is made up so I wish you the best

Thanks! I'll go the pedestal route at some point. Long story longer, I need a dedicated spot for the trailer and better lighting. It's going to require some grading meaning the machinery to trench the power lines will be on-site. I figure in the Spring I'll have that work done. The extension cord thing was meant to be temporary but has turned into a 6-year "temporary" as other projects took priority.

GMH · 08-24-2021, 08:04 AM

I’ve never liked the tri-tap cord ends. Especially cheap ones from China! I have seen a lot of them melted. Change both ends of that cord while you’re at it. The wire itself is likely OK.

turbojimmy · 08-24-2021, 08:42 AM

Quote:

Originally Posted by GMH

I’ve never liked the tri-tap cord ends. Especially cheap ones from China! I have seen a lot of them melted. Change both ends of that cord while you’re at it. The wire itself is likely OK.

I don't know what's not made in China anymore, but it was a pretty expensive cord. The male end is totally fine. No hint of heat damage and never gets warm. I suspect the wiring at the tri-tap. I can see it's melted inside at the crimp connectors that connect the tri-tap.

I put a 30A plug on it yesterday to eliminate the adapter. I turned the a/c temp down a bit so that it runs longer and more often. So far so good.

**sourdough** · 08-24-2021, 09:08 AM

Jim I used one of those ONE time and it did the same thing. I threw it away (entire thing) and got one without the plastic multi plug end and it lasted until the metal prongs began to deteriorate. Put in a 50A circuit an no more issues.

turbojimmy · 08-24-2021, 10:02 AM

Quote:

Originally Posted by sourdough

Jim I used one of those ONE time and it did the same thing. I threw it away (entire thing) and got one without the plastic multi plug end and it lasted until the metal prongs began to deteriorate. Put in a 50A circuit an no more issues.

It made sense at the time. The kids were always unplugging the RV for other stuff and forget to plug it back in. This way they could tap into the circuit and leave the RV plugged in. I guess I'll have to put my foot down and strongly remind them to plug the RV back in when they're done with whatever they're doing.

I'll run wire to a pedestal out there one day. Like I said before it's pretty far from the house and dark as a result. It would be nice to have power and lights out there. I did a 100-foot run for a new pool 2 years ago. It's not cheap to have done right, but worth it.

**sourdough** · 08-24-2021, 10:10 AM

Jim another thing to think about; I don't know who is plugging/unplugging what into what but if they are doing that and there is a load on the end, ie; say the AC in the RV and the plug is hot, there is going to be a "spark" as that load connects to power via the plug. Those hot "plug ins" will eat up a connection and cause what you are looking at.

turbojimmy · 08-24-2021, 10:18 AM

Quote:

Originally Posted by sourdough

Jim another thing to think about; I don't know who is plugging/unplugging what into what but if they are doing that and there is a load on the end, ie; say the AC in the RV and the plug is hot, there is going to be a "spark" as that load connects to power via the plug. Those hot "plug ins" will eat up a connection and cause what you are looking at.

Good point. I was hoping to mitigate that with the tri-tap. I'll have to let them know to shut the a/c down in the RV before plugging/unplugging.

turbojimmy · 09-19-2021, 09:06 AM

Okay - a quick update.

The new 30-amp plug I put on the end of the 10-gauge cord melted as well.

So I got looking at it and realized I had been overlooking something obvious. After the first meltdown, the blades of the RV's plug were coated in rubber/plastic. There had to be a lot of resistance. I cleaned them with a scotchbrite pad and replaced the female end of the extension cord once again. NOW it's finally working fine. No sign of heat whatsoever after a couple of weeks running the A/C.

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