This panel had a bunch of double taps on the neutral bar but the neutral and grounds were bonded. There were also double taps on the grounds and they seemed to be showing signs of overheating. Why would this be? I am thinking that this system already had a neutral/ ground bond elsewhere and having an additional here means the grounds were actually carrying the same load as the neutrals? or would this panel not being bonded at all cause this same result of the grounds carrying the same load as the neutrals? This was the main panel with the main cutoff in it. No other cutoff by the meter or anywhere else.
Lots of exposed copper wire seems discolored, chemical discoloration?
Any discolored copper pipe in the same dwelling?
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The spot you indicate as overheating looks more like an arc burn (momentary short to hot).
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I would also be interested to know who can diagnose this based on the information provided. The sarcastic side of me would just say “obviously a fault occurred, lightening strike or other”
Also, is it conclusively heat? The wire insulation does not appear to be effected.
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ya everything has it but just most visible on the grounds and no sign of heating on the insulation. Thermodynamics would allow heat transfer from ground or neutral to anything attached to that bar but the whole situation is just rather odd.
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yes the unaffected insulation was odd to me. The grounds were discolored as far as I could see where they were exposed (14-18"). Would be interesting to pull an outlet across the house and see what the ground wire looked like.
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the heat signature travels down the ground over a foot so its not localized enough for an arc flash IMO. there is no definitive area you could say “that’s where it shorted” on any of the wiring for bars.
plumbing was PVC
Su[quote=“Matthew Hice, post:9, topic:226467, full:true, username:mhice”]
plumbing was PVC
[/quote]
Supply Side?
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The photograph is not good enough for a definitive answer. Call for further evaluation (on the basis of the doubled neutrals) and let the electrician figure it out.
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yes, don’t see much copper here in FL
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Ya I stated it was an issue that needed immediate action by electrical contractor due to doubled neutrals and signs of overheating. Thermal showed no overheating at that time though.
That copper all looks kind of odd colored. I’m leaning with Simon on the chemical “burn” but best to let the electrician figure it out.
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I would be more concerned about the lack of a bonding screw (MBJ) than the color of the copper EGC’s. Obviously the “double taps” need to be corrected.
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That’s an odd burn because it doesn’t align with a source for the arc. I wonder if these wires were in a different panel or configuration where the damage occurred.
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And as Robert mentioned, there’s no green bonding screw installed and that may or may not be a contributing factor to the discoloration, but the neutral double taps need to be addressed as well so like Bob Stated, it’s a job for a qualified Sparky.
I am thinking that you have two conditions: 1) arcing due to one or more loose double-lugged neutral wires, as well as 2) some general evidence of a lightning surge in the area (not a direct hit) that heated the ground wires.
Why? Just a code violation. No safety issue. If this was a commercial panel then yes. No reason to ever disconnect anything in a live residential panel.
Even the triple EGC are not a safety hazard.
Remember if the AHJ approved this there is no defect. Also, if no electrical code was codified there is no defect.
Said no home inspector ever!
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