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Discussion Starter · #1 ·
In preparation for my panel swap and upgrade to 400 amp service, I've been working on digging around the current underground cable to route the 3" conduit under neath it.

I also cut away the drywall in the garage to make the panel swap and adding the 2nd panel easier.

I took a photo of what I found. Now, the burnt wire has been disconnected and replaced. Is this an example of a faulty breaker and a good reason to replace this panel?

What about the sheathing of nearby cables that are showing brown/orange spots which are likely due to heat?

My plan was to replace this panel and leave all the same circuits in it. Now I am considering moving some of these circuits to the new panel to the left to better balance out the load and to be able to cut the wire shorter and discard the damaged sheathing.

(Note: The panel on the left will have a 100 amp sub-panel off of it in the basement that has the 20KW electric heat for the HP on it...at peak it runs 80 amps. THe panel on the right will have the 100 amp sub-panel for the barn on it, which will only see high loads when I am welding or the RV is plugged in and both A/C units are running.)

THoughts on the bad wires?
 

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For safety, I would cut open the outer sheathing to examine the wires inside.
If they show no signs of damage, I would just tape the sheathing back in place. If the inner insulation on the wires is damaged I would replace the wiring.
Ron
 

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Who knows what caused it now, but those wires are nice and burnt. That's one of those "you just don't know how close you were" situations.

Cut the cable above and splice in some good wire in a j-box. Leave it accessible above the drop ceiling.
 

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That is one hacked up ugly original installation.:jester:

The "burn" marks???? They are in an odd location. Ususlly the heat is at the termination points, not in the middle of the run. Could they have been caused by an outside influence???

I'd look closely at them by opening up the sheath.

And....your PVC isn't 18" deep :laughing:
 

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About 5 wires showing brown marks
How long have you owned this house?
Any problem with those circuits before you found this problem?
Any date codes on the wires?
Are you installing new ground rods
Checking ground to water pipe etc?
 

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Discussion Starter · #6 ·
That is one hacked up ugly original installation.
And....your PVC isn't 18" deep :laughing:
Yes it is, it is 24" to the bottom of the pipe. :) Optical illusion in the photo I guess. If you look closely, you can see that it goes under the existing 200 amp service, which is at 18".

About 5 wires showing brown marks
How long have you owned this house?
Any problem with those circuits before you found this problem?
Any date codes on the wires?
Are you installing new ground rods
Checking ground to water pipe etc?
I've owned this house for 10 months and have had zero problems.

Yes, new ground rods.
No, not to water pipe....it is non conductive. (I have another thread going on this).
 

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I don't think I need to remind you (as others probably have) that a fundamental element (according to NEC and common sense) in calculating [continuous] load is to always take 125% of the actual load. (The other side of the equation is; --To use-- 80% of existing capacity)! In order not to strain the "Feeders"!
 

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Origin of burn marks on Sheathing???

It looks like one cable had suffered Mechanical damage: In plain English; A nail was driven through it. When it flamed out, it caused some peripheral damage to its neighbors. Imho. That cable, definitely has to be patched. J-box and all!!!:furious::no::drink: Don't Drink and Drive!!!
 

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Discussion Starter · #9 ·
It looks like one cable had suffered Mechanical damage: In plain English; A nail was driven through it. When it flamed out, it caused some peripheral damage to its neighbors. Imho. That cable, definitely has to be patched. J-box and all!!!:furious::no::drink: Don't Drink and Drive!!!
The cable in question is not active anymore and was cut on both ends....but I still found it interesting how much it burnt. Seems the breaker should have tripped before it got that hot and melted together.
 

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Where did the burned cable go? It looks a lot like the ground is not only burned, but blown in two in a few locations. If it went to a solidly grounded appliance or device (like the water heater or furnace), possibly the ground came in contact with the bus or main lugs in the panel.

Is there any evidence of arcing anywhere in the panel? This arcing likely would not be big, look for a spot where the ground wire might have welded itself onto something.

The burn marks on the other cables appear to be caused when the burned cable blew up. I don't think they're damaged.

Rob
 

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I don't think I need to remind you (as others probably have) that a fundamental element (according to NEC and common sense) in calculating [continuous] load is to always take 125% of the actual load. (The other side of the equation is; --To use-- 80% of existing capacity)! In order not to strain the "Feeders"!
I've run circuits for my Christmas lights at near 100% use for hours without a problem. New SE, panel & wire/outlets the works
I doubt many people are going to calculate how many watts they are using on a circuit when they plug things in
Most only worry after the breaker trips
 

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The cable in question is not active anymore and was cut on both ends....but I still found it interesting how much it burnt. Seems the breaker should have tripped before it got that hot and melted together.
I'm concerned that the cable that overheated was in contact with another cable somewhere else in your walls and burnt off its jacket/insulation.

Maybe I'm being overly paranoid.. :whistling2:
 

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I'm concerned that the cable that overheated was in contact with another cable somewhere else in your walls and burnt off its jacket/insulation.

Maybe I'm being overly paranoid.. :whistling2:
That's not paranoia, that's anticipating a problem. Well worth the effort to open as many wall as needed to check.
The alternative will require fireman with axes who will be opening the walls.
The damage should be greatest at the panel and diminish as you get further away.
This would be based on the time I pushed a snake accross a basement right into the open panel and hit the hot side. The snake got cherry red from the panel out until it melted and dropped to the floor.
Learned a lesson that day.
Ron
 

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He could hire a Electrician to check wires with a megger if he is concerned about them.
What's a meggar? Can it determine if the insulation has come off the wires?
Ron
 

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A megger is often a colloquial term for a circuit tester which puts a very high voltage at a very low current across two conductors to make sure that they are properly insulated.
 

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Discussion Starter · #17 ·
I'm concerned that the cable that overheated was in contact with another cable somewhere else in your walls and burnt off its jacket/insulation.

Maybe I'm being overly paranoid.. :whistling2:
The wires exit the wall in the garage attic and run for about 20 feet before going into the core house wall and to their final termination points.

The only signs of heat is immediately above the panel. The wires all look fine in the garage attic.

Thanks all.
 

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I don't think think you have anything to worry about.But if you do call electrician to megg out wire will detect any faults in wire.
 
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