Discoloration on copper wires in the main panel

Archive Public Archive
1

Originally Posted By: agarrett
This post was automatically imported from our archived forum.


http://www.nachi.org/bbsystem/usrimages/P/P1011343.JPG ]

2

Originally Posted By: phinsperger
This post was automatically imported from our archived forum.


Al,


Providing the rest of the panel is wired ok I think that what you are looking at is the result of a chemical reaction (ie. oxidization) rather than a thermal issue.

1) In order for copper to turn color due to heat it would have to surpass the thermal tolerance of the insulation. Since the insulation does not show signs of melting I doubt the wire would have reached the temperatures needed to turn color.

2) The discoloration is visible on the vast majority of circuits. Very unlikely that all those circuits would have been overloading and the main did not trip.

3) The main EGC also shows the discoloration. Again very unlikely that this wire would have receive enough current to turn it black without tripping something.

The fact that you never saw it to this extent before may mean that there is something in the vicinity (ie household chemicals) that is contributing to the oxidization effect.


Oh and by the way. Two black wire neutrals do not appear to be identified and have the insulation stripped.

--
.


Paul Hinsperger
Hinsperger Inspection Services
Chairman - NACHI Awards Committee
Place your Award Nominations
here !

3

Originally Posted By: pdickerson
This post was automatically imported from our archived forum.


I agree.


There is also a neutral/ground double tap at the far right.

4

Originally Posted By: cbuell
This post was automatically imported from our archived forum.


aren’t the two “black wire neutrals” oxidized ground wires?

5

Originally Posted By: mgault
This post was automatically imported from our archived forum.


cbuell wrote:
aren't the two "black wire neutrals" oxidized ground wires?


They do look to be slightly larger (sm gauge) bare grounds that have "blackened" a tad...

--
-Mike
A to Z Home Inspections, LLC

www.atozhomeinspections.net
6

Originally Posted By: phinsperger
This post was automatically imported from our archived forum.


After taking a second look I think you are right that they are grounds.

–
.



Paul Hinsperger
Hinsperger Inspection Services
Chairman - NACHI Awards Committee
Place your Award Nominations
here !