Age of Wiring based on materials used

[jon v]

I do handyman work in a large midwestern city.

I encounter a lot of older wiring that has been added to piecemeal, over the years. Yesterday, I was working in a house that had been built in 1911, or earlier, and originally had gas lighting. The wiring was added later, in some cases with the J boxes attached directly to the old gas piping.

I would welcome any information on the general ages of the wiring, based on the type of materials used.

I would characterize some general types that I find, in this area, as follows:

1) Indiviual wires strung on ceramic insulators, no conduit.

2) Fabric insulated wire (type V?) in black iron (steel?) pipe. These conduits are generally 1/2" rigid pipe with the bends field bent into the pipe, generally no fittings besides couplings and nuts at the j-boxes. The nuts on the pipe threads are hex shaped.

3) Steel Armoured Cable (BX?) with fabric sleeving over fabric insulated wire. Fittings are clunky, heavy castings. The nuts on the pipe threads are hex shaped.

4) Steel Armoured Cable with paper sleeving over fabric insulated wire. Fittings are somewhat lighter castings. Nuts on the pipe threads are stamped steel squares with 4 notches in the corners.

5) Steel armoured cable with paper sleeving over plastic insulated wire. Nuts on the pipe fittings are cup shaped steel with "star" shape.

and what I would consider "modern" materials:

Steel and Aluminum AC with cast zinc fittings, and EMT with cast zinc fittings.

Nonmetallic cable is not allowed in this area. BX is only allowed for pull-in remodeling type use.

I'm not looking for a discussion of code here, but I would find it very interesting to know what the approximate ages are of the various types of materials that I find.

Thanks for any info you can provide.

Best, Jon

[SQLit]

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NM not allowed for a single famly residence? What area are you located?

[Duane Bozarth]

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There was an article in Fine Homebuilding within the last several that has a timeline of some of these--the subject of the article was on evaluating existing wiring for upgrading. I'm sure it would be interesting given the question although it won't be complete it will provide a basic starting point...

[Duane Bozarth]

According to TOH (altho a number of years ago and maybe different by now) Chicago was one location during a renovation series they did there...

[RBM]

There is an excellent book called "Old Electrical Wiring" by David Shapiro, published by Mcgraw-Hill. It will answer any questions you have and any that it doesn't answer, you can email David directly

[Duane Bozarth]

BTW, that was No. 169 March or April this year...

[John Hines]

And some of the suburbs (like mine) have the same restriction. No non-metallic wiring.

It isn't hard to deal with, when you've been doing it all your life.

[jon v]

Thanks for your responses.

Chicago, Ill is correct. I believe NM is only allowed in sheds and outbuilding, and has to be exposed. But I am no electrician.

I will look for the publications cited. Thanks!

Little things sure make a big difference. How those electricians 60 years ago ever tightened those hex nuts inside a handy box is beyond me. I resort to replacing them with the star shaped nuts that respond to hammer and screwdriver tightening. Good thing that pipe threads are still the same!

Best, Jon

[SQLit]

Good ole Chicago... No wonder there are very few single family, single story dwelling in the parts of Chicago that I remember.

I had to find this link

There was a special pair of pliers ( lack of a better word ) that was used on the star washers. I have seen them but I never owned a pair. Water pump pliers/channel locks will work if they are small enough.

[SQLit]

I have never been to NYC except to visit Kennedy airport, just passing through. Again, I will say the same thing about the Chicago orginal post. Not to many single story single family homes. Right? I would also guess that Boston would be the same. Any place with multi-family and multi story would be the same.

What is a BORG?

It would appear my experiences in the western US are a tad different than the eastern big cities.

[Calvin Henry-Cotnam]

I beleive that much of the NYC area requires BX as well. A year ago, I visited some relatives in Brooklyn and they needed to add a circuit for a clothes dryer. All the home runs out of the breaker panel were BX.

The material they picked up included #14 BX to go with the 30A breaker, which of course is wrong, thanks to the BORG associate that served them. We went on a run to the local BORG to get the right amount of #10 and I was surprized to see that most, if not all, of the wiring sold there was all BX! (I don't recall actually seeing Romex there)

[John Hines]

No, there are single family homes in Chicago. A lot of the collar villages have the same restrictions. I do, and I'm 21 miles west of downtown Chicago.

Lots of single family homes in that area.

AFAIK, anything multistory has to be metallic wiring. NM is really only for residential use.

Slang for Home Depo, due to their boxy stores, monochrome colors, and a Star Trek TNG reference.

Do you have any chain stores selling building supplies from big boxy stores?

[SQLit]

Yes but I do not usually purchase from them. Since I have the ability to purchase from electrical wholesalers.

[Calvin Henry-Cotnam]

Big Orange Retail Giant.