Copper & Alum. in the same cable?

[Kyle Kubs]

Something very odd from yesterday's inspection. Two cables in the main panel, both with a cloth loom sheathing and thermoplastic insulation the Ungrounded and grounded conductors were Copper but the grounding conductor was Aluminum. This is something I've never encountered before. The panel access was very restricted due to an illegally finished basement with a narrow door in front of the panel but the hot conductor was not connected and just hanging in the panel with tape around the end, so I pulled the tape, looked at the cut end and everything and it was Copper. Oddly enough, it was also hot, but no need to get into that. So, am I looking at the Jackalope of the electrical industry? Ever heard of such a thing. The house was built somewhere around 1958 and this appears to be the original wiring but there were only two circuits like this.

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This second one looked a little different, almost like tinned Copper but again everything on the breakers and terminal bars was copper. Which I could believe more easily with the rag sheathing.

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The whole panel had a real hodge podge of wiring from regular copper NM with the undersized grounding conductor to this Copper/Alum hybrid to newer NM & NM-B

[Jim Katen]

Something very odd from yesterday's inspection. Two cables in the main panel, both with a cloth loom sheathing and thermoplastic insulation the Ungrounded and grounded conductors were Copper but the grounding conductor was Aluminum. This is something I've never encountered before. . . .

I can't recall having seen that before. I can't imagine why it would be a problem, though.

- Jim Katen, Oregon

[Eric B]

Is that possibly tin coated copper?

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