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vanswey
07-03-2020, 10:30 PM
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!!

http://https://drive.google.com/file/d/1a73D8-5pttcWTzY8BrCXgAzcdpEO3Beq/view?usp=drivesdk

Stumpy75
07-04-2020, 03:36 AM
Low voltage condition? Usually that will cause a breaker to trip, but not always....

+Ruff Rider
07-04-2020, 03:58 AM
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
07-04-2020, 04:42 AM
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
07-04-2020, 05:07 AM
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
07-04-2020, 05:28 AM
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
07-04-2020, 05:28 AM
If the connection was loose at the terminal strip it will cause this problem.

travelin texans
07-04-2020, 09:03 AM
Call your insurance agent before rewiring also!

Customer1
07-04-2020, 12:38 PM
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
07-04-2020, 02:14 PM
Thank you guys so much! I decided to do a insurance claim and Iíll let you guys know what the dealer says.

CedarCreekWoody
07-04-2020, 05:32 PM
Thank you guys so much! I decided to do a insurance claim and Iíll let you guys know what the dealer says.

Wise choice.

+Ruff Rider
07-05-2020, 03:49 AM
Care to explain why you think that?
Looks like a hot wire has come in contact with the neutral.

Bill-2020
07-05-2020, 04:44 AM
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
07-05-2020, 05:43 AM
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
07-05-2020, 01:43 PM
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
07-05-2020, 01:51 PM
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 thatís mounts the bar
in place, not a burnt off circuit. I count 6 breaker screws and 6 neutrals in place.

xrated
07-05-2020, 02:48 PM
I believe that 4th screw down is the screw thatís 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
07-05-2020, 03:28 PM
I actually count 7 wires coming off the neutral, but that would make sense because of the added circuit.

Yep, youíre absolutely right, 7. Huh... must have been the smoke from the grill in my eye.:D Thanks for keeping me honest.

xrated
07-05-2020, 05:01 PM
Yep, youíre absolutely right, 7. Huh... must have been the smoke from the grill in my eye.:D 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! :D

+Ruff Rider
07-06-2020, 03:41 AM
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?

xrated
07-06-2020, 04:00 AM
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
07-06-2020, 04:58 AM
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
07-06-2020, 05:57 AM
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. :lol:

flybouy
07-06-2020, 06:36 AM
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. :lol:

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
07-06-2020, 06:48 AM
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
07-06-2020, 07:09 AM
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. :banghead:I could ask him how his donkey was doing, what was for dinner, and how to hail a taxi.:banghead: I never felt so abandoned by education as I did that day.

Bill-2020
07-06-2020, 09:00 AM
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
07-06-2020, 10:09 AM
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. :banghead:I could ask him how his donkey was doing, what was for dinner, and how to hail a taxi.:banghead: 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
07-07-2020, 11:01 AM
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
07-07-2020, 11:33 AM
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
07-07-2020, 12:30 PM
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
07-07-2020, 01:37 PM
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
07-07-2020, 05:12 PM
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 whatís in the rear of the panel. Follow that circuit around and it appears that itís 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 didnít 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
07-07-2020, 06:33 PM
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
07-07-2020, 06:41 PM
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! :banghead:

rhagfo
07-07-2020, 06:46 PM
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!!

http://https://drive.google.com/file/d/1a73D8-5pttcWTzY8BrCXgAzcdpEO3Beq/view?usp=drivesdk

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
07-07-2020, 06:57 PM
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
07-09-2020, 09:36 AM
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
07-09-2020, 02:40 PM
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
07-09-2020, 03:33 PM
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.

Snoking
07-10-2020, 05:35 AM
Time to call in a qualified electrician to figure out what happen. I was warned to check the tightens of all the panel connections when we purchased our 5th wheel in 2016. It is a wonder that the unit did not burn to the ground! A good EMS might have picked this issue up earlier.

Randyf7f
07-10-2020, 06:13 AM
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.

Yes, xrated, you are correct. My apology. I meant to say 'grounding buss'. My error should have been obvious by the context of my post.

Sarge2
07-10-2020, 06:27 AM
[QUOTE=JRTJH;398372]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.

Although it's probably a mute point now, I have to agree with JRTJH... That large main ground wire at top appears to me to be the primary ground for the bus bar... that being said, it appears that because that one was so badly corroded it the system tried to make the rest of the wires the primary gound wire.... hence the burned insulation from the heat of trying to FIND a ground somewhere... I've seen this with a lot of automotive wiring where the system looks for a ground and will attempt to get one thru whatever other ground may be available... JMHO..

xrated
07-10-2020, 07:25 AM
[QUOTE=JRTJH;398372]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.

Although it's probably a mute point now, I have to agree with JRTJH... That large main ground wire at top appears to me to be the primary ground for the bus bar... that being said, it appears that because that one was so badly corroded it the system tried to make the rest of the wires the primary gound wire.... hence the burned insulation from the heat of trying to FIND a ground somewhere... I've seen this with a lot of automotive wiring where the system looks for a ground and will attempt to get one thru whatever other ground may be available... JMHO..

That isn't the ground buss, it is at the bottom of the picture. The buss that is on the left side is the neutral buss and all the neutral wires will carry the same exact current as the hot wire that is associated with each of the circuits.

flybouy
07-10-2020, 07:50 AM
[QUOTE=JRTJH;398372]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.

Although it's probably a mute point now, I have to agree with JRTJH... That large main ground wire at top appears to me to be the primary ground for the bus bar... that being said, it appears that because that one was so badly corroded it the system tried to make the rest of the wires the primary gound wire.... hence the burned insulation from the heat of trying to FIND a ground somewhere... I've seen this with a lot of automotive wiring where the system looks for a ground and will attempt to get one thru whatever other ground may be available... JMHO..

Agree with Xrated comments but would just add that I don't think it's corrosion on the main neutral. The top (in relation to how the picture is oriented) white wire is a stranded wire and not solid copper. When a stranded wire heats up the strands, being of a smaller diameter, will burn off where as a solid copper wire will not. The green powdery substance appears to me to be the remnants of burned copper.

Again, this is all guessing as none of use are there to really look, disassemble, and diagnose.

Gord
07-10-2020, 04:00 PM
Time to call in a qualified electrician to figure out what happen. I was warned to check the tightens of all the panel connections when we purchased our 5th wheel in 2016. It is a wonder that the unit did not burn to the ground! A good EMS might have picked this issue up earlier.
It would seem to me Snoking has hit on the issue here. It is hard to determine from the one picture, to my eye it appears that all of the screws on the neutral bus bar are screwed right down to where they bottom out. This type of bus bar works best when the stripped wire sticks out of the opposite side from where it enters so that you get a good solid connection. When the repairs are done I suggest also looking at the ground bus connections, as some of the screws are screwed in further than others that are on the same size conductors. Hope you all have a great weekend. Gord

jimborokz
07-10-2020, 04:44 PM
The heavier wire at the bottom and very heavy wire at the top show green at the connection. It may be just green from overheating copper, but if it is corrosion I would strongly suspect that as the underlying problem causing excessive resistance. Also most of the insulation of the smaller wires show overheating not at the connection but farther up the wire so the source of the heat for them was something else, likely heat from the wires that were actually overheating.

Gord
07-10-2020, 05:33 PM
Looking at the picture a little closer leads me to think the warning label should be at the bottom of the photo with neutral bus bar then at the top of the photo. This would also help to explain the heat distortion of the plastic bezel which is beside the neutral bus in the photo. Looking the neutral termination screws shows that their finish is distorted. The screw heads should be the same color as the termination screw heads on the ground bus.

Bill-2020
07-10-2020, 06:32 PM
Looking at the picture a little closer leads me to think the warning label should be at the bottom of the photo with neutral bus bar then at the top of the photo. This would also help to explain the heat distortion of the plastic bezel which is beside the neutral bus in the photo. Looking the neutral termination screws shows that their finish is distorted. The screw heads should be the same color as the termination screw heads on the ground bus.

I agree on the orientation comment. Good point. There is also the debris around that label that "fell down" around it.