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Older NM Cable Information?

491 Views 3 Replies 4 Participants Last post by  Let it Snow
Hi everyone,
I had a quick question about the old wiring in my farmhouse from the late 1800's. I don't think this house got power for a long time because the oldest wiring around the house is two-wire black NM cable that's almost like a tarred cloth on the outer sheathing with paper surrounding the inside conductors, which are insulated with plastic (they do not seem to be insulated by rubber because it is still pliable). The hot is black insulated but the neutral's white insulation is so old that it seems to have taken on a gold color. I was curious as to maybe the time period that this NM could've been made around and whether or not it may contain asbestos. I am curious because I rewired everything that was exposed in my basement, which was only two long runs of the stuff. I treated it as if it contained asbestos, trying not to crack it, shave it, etc. Anytime I had to cut it I wet it and then cut it, soaking the cut ends after. I'm just curious to see what you guys think about it. Thanks
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I never worried about asbestos in wire insulation. Even if it had some, you would have to powder it and disperse it in the air, then breathe it for a while.
It sounds like our previous farmhouse; built in the 1890s and no evidence of previous K&T. I have never heard of asbestos in older residential wiring. As you say, tar impregnated cloth and paper. Discolouration of the white insulation is common. I'm not sure if it a result of heating or simply a reflection of the manufacturing of the day.
What you are seeing is the first generation of cable used after Knob & Tube.
It's from the late 1920-pre WWII.
It does not contain asbestos.
The only wire I've seen to contain asbestos is high temperature wire used in oven, cooktops and kilns in the 1960's.
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