Non-Metallic wiring from the 50's

I saw today what appears to be non metallic wiring from the 50’s - three wires with a ground (bare copper) wrapped around the wiring jacket. Similar to the way you do wiring with BX wiring. The jacket was silver but most seemed to have faded away leaving it black.

I am not at a computer that I can upload a picture but can at a later date.

Question - any concerns here? My guess is the plugs and switches are ungrounded.




He is an image (also posted below)


Your post title says metallic, yet your post body says nonmetallic. Which one is it? It’s helpful to post pictures of this stuff.

It would be somewhat common to see ground wires of this vintage wrapped back around the jacket. Some installers did this, since the ground wasn’t really required to hook to anything during that period. Some installers did this simply because they didn’t know what to do with it.

If the jacket is metallic and substantially round in profile, it’s possible that you’ve run across some of the old lead sheath stuff. It was the precurser to UF cable.

Hi. Marc;

Is it conceivable that he was referring to the metalic look of the non-metalic wiring used in those days?

I remember when that stuff was used and the ground wire was of 18 gauge and usually cut off because the outlets were only two prongs and no ground.

The house I have today is and has this type of wiring.

Just an opinion.

Marcel :slight_smile:

Maybe so. I was just taking a stab in the dark. Some of the silver and blue braided jacket stuff did have a metallic paint type outer finish.

Sorry about that- the header should be non-metallic wiring from the 1950’s

Although this may exceed some of the SOP one way to remove the guess work is removing a cover plate screw or two.
Also confirms branch wire type and if side wire or back wire conditions may exist.

Like Marc says, a lot of guys didn’t know what to do with the ground wire so they just looped it back under the Romex clamp. It almost works as a ground. I have also seen it looped out and wrapped around a Romex clamp screw

Almost, when discussing grounding is the same as using it to discuss pregnancy or death. Doesn’t quite fit into the conversation.

Yeah, I see the picture now. That was a popular thing to do during a certain time period with the ground wire. You should consider circuits terminated in such a way to be essentially ungrounded. Should a ground fault occur, the breaker might trip, but when terminated in this manner, it’s a coin toss. It was an okay thing to do during the time period in which it was installed, in all likelihood, but doesn’t really pass muster with today’s standards.

That is why article 250 is the biggest section in the NEC. Grounding is important but in the 50s when they were just starting to bring a ground to residential outlets the sparkies were thinking any grounding method was better than nothing. I bet a ground wire twisted around NM and securely clamped under the Romex connector is probably good enough to pass the “sure test” test. The problem is it isn’t secure enough to pass the article 250 test. When I was working I was the “grounding” inspector. I spent a disproportionate amount of time verifing that all grounding/bonding was done properly.
That is the foundation that other electrical safety is built on.
I will beat Will to the punch and say EMT with the supplimental green wire ground in it is probably as safe as an electrical system gets. Unfortunately it is also more expensive than most home buyers are willing to tolerate.