Melting wires

[xrated]

Originally Posted by +Ruff Rider

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?

The only wires that don't, or shouldn't have current running through them would be the green or bare ground wires. The hots and neutrals are what comprise a "complete circuit"....and like I said, you're comment was a guess....and I'm not seeing it.

[flybouy]

Originally Posted by +Ruff Rider

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?

The neural wire in an ac circuit does complete the circuit. I would suggest you do some research and read up on how it works so you can give an educated opinion. The heat buildup would only happen to a circuit in use. And yes, the neutral does carry the load back to the source. That's why the neutral wire is sized to match the line wire on any given circuit.

[xrated]

Originally Posted by flybouy

The neural wire in an ac circuit does complete the circuit. I would suggest you do some research and read up on how it works so you can give an educated opinion. The heat buildup would only happen to a circuit in use. And yes, the neutral does carry the load back to the source. That's why the neutral wire is sized to match the line wire on any given circuit.

When I first started my Electrical Apprenticeship, way back in 1977, my first Journeyman saw that I was somewhat intimidated by the complexities of some of the equipment that we would be troubleshooting and repairing (I was brand new....like the second or third week in the program). So he told me something that was supposed to try and help me feel more at ease....."Electricity is pretty simple....kid.....You got one wire a comin' and one wire a goin'...that's it!" I never forgot that statement, but of course I did come to realize that it wasn't "quite" that simple.

[flybouy]

Originally Posted by xrated

When I first started my Electrical Apprenticeship, way back in 1977, my first Journeyman saw that I was somewhat intimidated by the complexities of some of the equipment that we would be troubleshooting and repairing (I was brand new....like the second or third week in the program). So he told me something that was supposed to try and help me feel more at ease....."Electricity is pretty simple....kid.....You got one wire a comin' and one wire a goin'...that's it!" I never forgot that statement, but of course I did come to realize that it wasn't "quite" that simple.

I was an adjunct faculty member that instructed several electrical curriculums for an HVACR program at a local college. I tought both lectures and labs with students that were mainly working adults that wanted to better themselves. The most dangerous students were those that had "some" experience and thought they knew everything. They were the ones that I had to monitor closely to keep them from killing themself or their classmates.

IN a forum setting there are very few ways to "verify" the knowledge of the person asking "how do I rewire my panel from 30 to 50 amps" or "can I back feed my generator into an outlet" etc. That's why I'm reluctant to give advice to someone that doesn't know what a VOM is much less how to use it. It's just impossible to express a term of fundamental electricity into a few paragraphs on a forum.

[xrated]

Originally Posted by flybouy

I was an adjunct faculty member that instructed several electrical curriculums for an HVACR program at a local college. I tought both lectures and labs with students that were mainly working adults that wanted to better themselves. The most dangerous students were those that had "some" experience and thought they knew everything. They were the ones that I had to monitor closely to keep them from killing themself or their classmates.

IN a forum setting there are very few ways to "verify" the knowledge of the person asking "how do I rewire my panel from 30 to 50 amps" or "can I back feed my generator into an outlet" etc. That's why I'm reluctant to give advice to someone that doesn't know what a VOM is much less how to use it. It's just impossible to express a term of fundamental electricity into a few paragraphs on a forum.

I totally agree with that ^^^^ I also spent a few years teaching Electrical Controls and D.C Crane control in our apprenticeship program. I worked in a steel mill and almost every one of our overhead cranes was 250VDC. I worked in the Steel Making Dept, and we had 6 ladle cranes that had a Main Hoist rating of 400 Tons! That's not a typo....400 Tons or 800,000 lbs. So DC crane control was vital to the apprenticeship program for our purpose. It was a very enjoyable time, both the classroom sessions and the labs that we did. I would always schedule a field trip during the semester to bring the students into the steel mill and we would access one of the overhead cranes and they would actually get a chance to see, in person, the control boards, and the enormity of the equipment.....it was a Kodak moment when some of the them saw the size of the cranes.

[flybouy]

High voltage DC is more dangerous than AC. When I was young I worked for an outfit in Baltimore and they would send me out to ships in the bay, grain elevators and cranes in the inner harbor, natural gas pumping stations, refineries, etc. Also went to Beth. Steel to work on or diagnose controls on DC motors, eddy current drives, motor generators, etc. My only regret was not taking pictures but back then I wasn't going to take an expensive 35mm camera to a job site.

I'll never forget going down a tunnel near the Susquehanna River to check out a 1,000 + hp electric motor that was constructed to pump water from the river to the reservoirs in Baltimore in case of a drought. It was called the Susquehanna Conduit and most people aren't even aware of it's existence. The pipe was large enough to drive a car thru (108" dia.) and you literally could step inside the motor to check the brushes on the rotor.

I learned a lot from those experiences. I also learned that my 5 years of Spanish language classes were useless when I was trying to speak to a ship's electrician about a controler issue on the ship's anchor windlass. They didn't teach me the spanish version of phase, diode, rectifier, etc. I could ask him how his donkey was doing, what was for dinner, and how to hail a taxi. I never felt so abandoned by education as I did that day.

[Bill-2020]

Stepping into a motor to check the brushes??!! Wow! That would be something to see in person. My father was a field service engineer for IBM - he used to climb into and around the punch card machines and then the mainframes, way back in his day.

[xrated]

Originally Posted by flybouy

High voltage DC is more dangerous than AC. When I was young I worked for an outfit in Baltimore and they would send me out to ships in the bay, grain elevators and cranes in the inner harbor, natural gas pumping stations, refineries, etc. Also went to Beth. Steel to work on or diagnose controls on DC motors, eddy current drives, motor generators, etc. My only regret was not taking pictures but back then I wasn't going to take an expensive 35mm camera to a job site.

I'll never forget going down a tunnel near the Susquehanna River to check out a 1,000 + hp electric motor that was constructed to pump water from the river to the reservoirs in Baltimore in case of a drought. It was called the Susquehanna Conduit and most people aren't even aware of it's existence. The pipe was large enough to drive a car thru (108" dia.) and you literally could step inside the motor to check the brushes on the rotor.

I learned a lot from those experiences. I also learned that my 5 years of Spanish language classes were useless when I was trying to speak to a ship's electrician about a controler issue on the ship's anchor windlass. They didn't teach me the spanish version of phase, diode, rectifier, etc. I could ask him how his donkey was doing, what was for dinner, and how to hail a taxi. I never felt so abandoned by education as I did that day.

It appears that we have a lot in common on our past as far as job skills and such. To most folks, seeing some of the huge motors/generator sets and Overhead cranes, would just be something to make your jaw drop down in awe. I didn't spend much time in the "Hot Strip" part of the steel mill except during my apprenticeship rotations to every department. I machinery there was just as big as the steel making area where I worked, just in a different way. I can clearly remember the 4 big MG sets that supplied power to the finishing mill stands (7 finishing stands total). Those MG sets had a motor in the middle of them, which huge 750VDC generators on both ends of the motor. I forget the size of the generators in Kws, but the motors I clearly remember were 20,000 HP each (4 of them), and they were synchronous motors and the applied voltage was 13,800VAC. I can also remember when the Hot strip got ready to start up, after a maint. outage, the utilities supervisor had to call IL. Power company and get permission from them to start the motors.....one at a time, to prevent a brown out in the hot summer months. They knew that they had to be started on the midnight shift, early morning, when the electrical consumption was at the lowest part of the day. They literally shook the entire motor room when they started...and the motor room was roughly 200' wide, by a little less than a 1/4 mile long. Big stuff for sure, and I'm better off for the experience as an Electrician.

[+Ruff Rider]

Originally Posted by flybouy

The neural wire in an ac circuit does complete the circuit. I would suggest you do some research and read up on how it works so you can give an educated opinion. The heat buildup would only happen to a circuit in use. And yes, the neutral does carry the load back to the source. That's why the neutral wire is sized to match the line wire on any given circuit.

I guess you don't have any idea why a natural wire got hot enough to melt the insulation. He has a short. Hot wire coming in contact with the natural. COMPLETING the circuit without a load.

[flybouy]

Originally Posted by +Ruff Rider

I guess you don't have any idea why a natural wire got hot enough to melt the insulation. He has a short. Hot wire coming in contact with the natural. COMPLETING the circuit without a load.

Why do you insist on arguing without knowledge or facts? Where did you get the idea that this happened with no load present on the electrical panel? As I originally stated one can only guess as we aren't there to do a thorough investigation.

Again, I'd urge you to educate yourself and do some reading on the subject. At this point, I can't view this type of comment as anything but trolling.

[xrated]

Originally Posted by +Ruff Rider

I guess you don't have any idea why a natural wire got hot enough to melt the insulation. He has a short. Hot wire coming in contact with the natural. COMPLETING the circuit without a load.

You know, the more you post, the deeper you bury yourself with uneducated comments that thoroughly convince me that: 1. You shouldn't post about things you know nothing about. 2. You should just stop before it gets even worse........if that is even possible.

[sourdough]

Originally Posted by flybouy

Why do you insist on arguing without knowledge or facts? Where did you get the idea that this happened with no load present on the electrical panel? As I originally stated one can only guess as we aren't there to do a thorough investigation.

Again, I'd urge you to educate yourself and do some reading on the subject. At this point, I can't view this type of comment as anything but trolling.

^^^^^On this I agree.

[Bill-2020]

Originally Posted by 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.

I'm here to correct myself. This posting got me thinking, so I pulled the cover off mine this evening to check the connections again (been there, done that once, but measure twice, cut once right?). I then see the same taped hot wires with a wire nut as I pointed out on the OPs picture. Turns out that this shared circuit is for both the wall outlets and the converter, labeled as "Rec/Con" all on a single 15amp breaker.

So there is no "extra" circuit in the OPs. I also noticed that someone at Keystone connected two neutrals together instead of one in each position on mine. I've corrected that.

Hope the OP gets this figured out and resolved.

[xrated]

Bill 2020....having both neutral wires in the same lug on the neutral bus will not really hurt anything, as long as the connection is tight. It's not exactly the way to do things, but should not cause any issues electrically.

[Bill-2020]

Originally Posted by xrated

Bill 2020....having both neutral wires in the same lug on the neutral bus will not really hurt anything, as long as the connection is tight. It's not exactly the way to do things, but should not cause any issues electrically.

Yes, understood. There was an OCD component at play there... I had the tool in my hand, saw it could be made right, so I dug in. Damn OCD!

[rhagfo]

Originally Posted by 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!!

I would look closely at the 5th cable down on the neutral buss bar. It appears to be the most charred, I think the heat from that one connection caused the buss bar to get hot and char the others, and deform the side of the box.

ON EDIT: What is on the 3rd breaker from the left, looks to be frrding two circuits, one going to the taped wire nut connection in the top right corner that looks like it also got a bit warm. What size (Amps) is that breaker?

[Bill-2020]

Originally Posted by rhagfo

I would look closely at the 5th cable down on the neutral buss bar. It appears to be the most charred, I think the heat from that one connection caused the buss bar to get hot and char the others, and deform the side of the box.

ON EDIT: What is on the 3rd breaker from the left, looks to be frrding two circuits, one going to the taped wire nut connection in the top right corner that looks like it also got a bit warm. What size (Amps) is that breaker?

See my post above with a picture of mine - it's the converter and outlets on a 15amp breaker. You can barley make out the taped wire nut in mine (too dark).

[Randyf7f]

I typically see this type of damage from a poor, or high resistance connection. One thing that is interesting is that there appears to be some damage around the small, insulated wire on the neutral buss. Heat or corrosion (but not backed-up by any heat damage to the insulation). Should not be any current (heat) in that buss anyway. Also not sure what the white residue on the breakers is - corrosion coming out of the breakers, or just debris from the burnt wires? Any chance the panel has been near any chlorine bleach or other corrosive fumes?

[xrated]

Originally Posted by Randyf7f

I typically see this type of damage from a poor, or high resistance connection. One thing that is interesting is that there appears to be some damage around the small, insulated wire on the neutral buss. Heat or corrosion (but not backed-up by any heat damage to the insulation). Should not be any current (heat) in that buss anyway. Also not sure what the white residue on the breakers is - corrosion coming out of the breakers, or just debris from the burnt wires? Any chance the panel has been near any chlorine bleach or other corrosive fumes?

There is heat and damage on every single wire on the neutral buss. What do you mean there shouldn't be any current on that buss?? The neutral wire in a circuit carries the exact same current as the hot wire for the circuit.

[oldnjrver]

I have a fundamental understanding as a result of my own past faux pas and think that there was some resistance in that neutral circuit. Either a loose connection or corroded connection could cause the bus to heat up, especially under heavy load or a short somewhere in the system. With a load on some of these circuits and a loose or corroded main connection that bus would heat up enough to char those wires especially if a low voltage situation existed. An air conditioner with a refrigerant leak would draw extra current further exascerbating the situation. I would definitely get an EMS and check the current drawn in each of those circuits, make sure there are no shorts anywhere.
As a humble ex millwright That's my 2 cents.