Discoloration on Insualtion of wires

[Jeff Eastman]

.......

[Nick Ostrowski]

Jeff, any other visual evidence such as corrosion or melted insulation? Was the wire gauge properly sized for the serving breaker?

[Jerry Peck]

Could not tell from the photo, but that is just the outer covering on THHN/THHW/etc., and it probably was not sunlight resistant and may have been left open for an extended time, or, possibly some type of clearner/solvent/lubricant was wiped on the conductor?

Only 90% sure from the photo, but I'd probably not say anything about that (unless there was something more to make me suspicious of another problem).

[Tim Moreira]

I'd go with a powder or lubricant used at the installation.

I would not write that up alone.