Melting wires

[vanswey]

I have a 2018 Springdale 24bhwe and my Dometic air conditioner just stopped working. I bought the trailer brand new and have used it for a total if 30 nights.

Everything was running fine then I noticed the breaker at the campsite had tripped. I thot nothing of it and reset the breaker and the trailer worked perfectly again. About 6 hours later the ac stopped working. I checked the campsite breaker and it had not tripped so I opened the fuse panel in the trailer to see if the breaker had tripped which it did not. However I looked at the wires going into the buss and a lot of them looked charred or melted. Any ideas how this would happen? Thank you!!

[Stumpy75]

Low voltage condition? Usually that will cause a breaker to trip, but not always....

[+Ruff Rider]

I think that a hot wire has grounded out on the main neutral wire. Every one got hot enough to melt the sheathing. I would unplug the trailer and get out the voltage meter and check for a short. Also look at the converter to make sure it didn't cause this.

[flybouy]

I'd like to see more of the upper right hand corner of the picture as it is posted. Looks like some tape that melted?

A direct ground from a line to neutral should trip the breaker immediately. As none of us are there the best any of us can do is make an educated guess. My guess, from looking at the damage is a loose neutral on that neutral buss. The lugs in the center are more discolored and those neutral wires are burned the most.

A loose lug will allow the wire end to arc like a welding rod. As this initially doesn't increase the amperage of the circuit the breaker doesn't trip. The longer this goes on the more heat builds up until the insulation starts to melt. Eventually the heat and arcing will create enough deposits to create a high resistance. The more resistance the higher the amps.

You are very fortunate that your camper did not catch on fire. Now to repair it. That neutral buss bar needs to be replaced. Every wire in that buss bar needs to be cut back until you get past the damaged area, i.e. No discoloration, no "hardening" of the insulation or wire. This may require replacing or splicing on new wire to get the wire to reach.

All connections should be checked to ensure good contact, the breaker, the ground and neutral buss screws, wire nuts, etc. Obviously this is with the unit unplugged and if you are not comfortable or experienced then hire a professional .

[xrated]

Originally Posted by +Ruff Rider

I think that a hot wire has grounded out on the main neutral wire. Every one got hot enough to melt the sheathing. I would unplug the trailer and get out the voltage meter and check for a short. Also look at the converter to make sure it didn't cause this.

Care to explain why you think that?

[JRTJH]

In your photo in the first post, looking at the vertical buss bar and numbering the connectors from top (1) to bottom (8), there is green corrosion on the copper wire at connectors 1,5 and 8. The extent of that corrosion can't be determined by looking at the photo, but it may have started at a bad crimp (unlikely on 3 wires) or there may be some significant condensation/water intrusion.

You say that you bought it new in 2018, used it 30 nights. It's now 2020, so essentially, the trailer has sat idle with no use for 2+ years ??? If so, there may be some "contributing factors" from lack of use.

At any rate, that corrosion may play a part, a busy campground electrical grid producing a low voltage condition will contribute as will operating the trailer without an EMS to protect the systems from that low voltage condition.

At this point, as stated, check the wiring carefully, rewire the sections of wire that are burned, BE VERY CAREFUL when reconnecting wires not to cross wire anything !!!!!!

Then stand back, try it and it'll either "produce early fireworks" or function as before. There are very few A/C repairmen who will work on RV Air Conditioning systems, so if that doesn't work, you'll likely be buying a new top unit, about $539 most places for a 13,500 BTU unit and a bit more for a 15K unit.

I'd suggest upping that repair cost to around $800 by adding a EMS to the repair to prevent such damage "next time"....

Dometic and Coleman A/C's are warrantied for 2 years, so if you "bought it new in 2018" and it's not yet 24 months, contact a dealership or A/C service center for that brand ASAP (before the warranty expires)...

[ajlight]

If the connection was loose at the terminal strip it will cause this problem.

[travelin texans]

Call your insurance agent before rewiring also!

[Customer1]

Loose connections cause arcing and arcing causes heat. Based on the evident corrosion on wires this has been a ticking time bomb for a while, probably since new.

Everything needs replaced. All wires need cut back to nice pristine copper and insulation.

[vanswey]

Thank you guys so much! I decided to do a insurance claim and I’ll let you guys know what the dealer says.

[CedarCreekWoody]

Originally Posted by vanswey

Thank you guys so much! I decided to do a insurance claim and I’ll let you guys know what the dealer says.

Wise choice.

[+Ruff Rider]

Originally Posted by xrated

Care to explain why you think that?

Looks like a hot wire has come in contact with the neutral.

[Bill-2020]

Just an observation. The last neutral down appears to go through the side of the panel without the usual strain relief or clamp that typically holds the romex, like what’s in the rear of the panel. Follow that circuit around and it appears that it’s an added circuit. Marshall noted melted tape earlier, top right side. Looks to me like a wire nut (orange) taped with 3 hot wires, one of those 3 goes through the side of the panel along side the neutral and ground. If the neutral that was added didn’t get tightened enough, it could potentially cook everything above it. But then again, any significant heat on that bar will radiate to the others either above or below the heat source.

[xrated]

Originally Posted by +Ruff Rider

Looks like a hot wire has come in contact with the neutral.

You must have really good eyesight.......I'm not seeing it. So basically, it just a guess and nothing factual.

[kcamp99186]

I agree also, that it is most likely to be a lose connection on the bus bar. Is there a burnt off wire under that 4th screw terminal down? Hard to tell from the pic, but you may have lost a circuit there. Just over the heavy white wire in the center, below the orangish burnt wire, it looks to me like the other end of a burnt off wire. If so, that could have been the original culprit.

[Bill-2020]

Originally Posted by kcamp99186

I agree also, that it is most likely to be a lose connection on the bus bar. Is there a burnt off wire under that 4th screw terminal down? Hard to tell from the pic, but you may have lost a circuit there. Just over the heavy white wire in the center, below the orangish burnt wire, it looks to me like the other end of a burnt off wire. If so, that could have been the original culprit.

I believe that 4th screw down is the screw that’s mounts the bar
in place, not a burnt off circuit. I count 6 breaker screws and 6 neutrals in place.

[xrated]

Originally Posted by Bill-2020

I believe that 4th screw down is the screw that’s mounts the bar
in place, not a burnt off circuit. I count 6 breaker screws and 6 neutrals in place.

I actually count 7 wires coming off the neutral, but that would make sense because of the added circuit.

[Bill-2020]

Originally Posted by xrated

I actually count 7 wires coming off the neutral, but that would make sense because of the added circuit.

Yep, you’re absolutely right, 7. Huh... must have been the smoke from the grill in my eye. Thanks for keeping me honest.

[xrated]

Originally Posted by Bill-2020

Yep, you’re absolutely right, 7. Huh... must have been the smoke from the grill in my eye. Thanks for keeping me honest.

I'm just glad there weren't 11 wires there....I'd have to take one of my shoes off to finish counting!

[+Ruff Rider]

Originally Posted by xrated

You must have really good eyesight.......I'm not seeing it. So basically, it just a guess and nothing factual.

Maybe you can enplane how a wire that has no power running through it gets hot. Only way to make a wire hot is to complete the circuit. Thats why I said that a hot wire has come in contact with the natural. Has OP checked to see if he has a loose wire?