Al branch circuits weren't expected here

[John Kogel]

The house dates back to the mid 50's, but there are no two prong outlets anywhere.

What is there is Al branch circuits, which I wasn't expecting to see. The hip roof and stucco fits the age, so I think the ungrounded wiring was replaced with solid Al branch circuits in the mid 60's. The Al conductors have silver cloth jackets.

Yes, I know it is an old Federal Pacific piece of crap panel.

Mr Handyman has added a #14 gauge copper neutral under the same screw as a #12 gauge Al neutral. Brilliant.

It's a little reminder to expect the unexpected.

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[John Dirks Jr]

Are you positive it wasn't tin coated copper instead of AL? Tin coated copper would fit the mid 50's.

[Bill Kibbel]

Look closely at the cut ends - clearly solid AL (nice clear pics btw). The shiny silver cloth jacket gives it away too.

[John Dirks Jr]

I have to admit, every time I've found tin coated copper it had cloth conductor insulation rather than plastic as shown in John's pictures.

What about the jackets on tinned copper, that's usually metal armor, correct?

[Jim Katen]

I have to admit, every time I've found tin coated copper it had cloth conductor insulation rather than plastic as shown in John's pictures.

What about the jackets on tinned copper, that's usually metal armor, correct?

The tinning was put there to prevent the copper from being in contact with the old rubber insulation, which would have reacted with copper.

You'll find tin coating on any old copper wiring that had rubber insulation, including those that were assembled with metal jackets and cloth jackets.

[Jim Port]

I have never seen any AL NM cable for branch circuits that did not have plastic sheathing.

[John Dirks Jr]

I have never seen any AL NM cable for branch circuits that did not have plastic sheathing.

That's sort of what threw me.

[John Dirks Jr]

Look closely at the cut ends - clearly solid AL (nice clear pics btw). The shiny silver cloth jacket gives it away too.

I agree the cut cross section of the conductor can be a conclusive way to identify AL branch. However, when it comes to the shiny silver jacket, that can go either way. The pic below is cables in my house. The 12/2 in the shiny silver cloth jacket is copper all the way.

Either way, prior to this thread, I would not have expected to find AL conductors inside a cloth jacket. All that I have found were plastic insulators plastic jackets.

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[Jim Katen]

I have never seen any AL NM cable for branch circuits that did not have plastic sheathing.

Of course, now, you can't say that anymore. . .

[John Kogel]

I couldn't find any labeling on the silver jackets around the panel, but I did catch it by accident up in the attic. Dusty air was pouring up thru this gap between the batts.

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[Douglas Hansen]

We had a very similar aluminum cable in the mid-1960's that was made by Kaiser. The outer sheathing was a plasticized fiber of some sort, kind of a stepping stone between the old rag-wrap copper NM and the PVC sheathing of the late 60s.