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Discussion Starter · #1 ·
I have over 100’ of 14/3 that I’d like to use for some 3 way recessed lights. The cable looks to have been manufactured in 1993, I picked it up cheap on Craigslist.

Is this good to use or should I just buy new MC / NM cable?

I know with older BX you need a bonding strip in order for the cable itself to ground. It looks like this MC has a bare ground wire inside so I figure it’s perfectly safe to use the bare ground and be good.

On a side note, when did they start covering ground in green and why?

Thanks for the education.

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A "Handy Husband"
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What you have is Type AC cable and it is perfectly compliant to use. The bare aluminum wire is the bonding strip, you either can cut it off at the sheath or wrap in back along the outer sheath; do not connect to the box with screw or to the device.. You need to use a red insulating bushing (red head) when installing the cable into a connector.

A metal jacketed cable with a green insulation on a copper ground wire is Type MC cable.
 
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That's correct! That's an older AC cable and is safe to use.
The MC cable sheet is thinner and not compliant by itself for grounding, hence the green ground inside.
 

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Discussion Starter · #4 ·
What is the reason for not connecting the bare wire to the j box/ other grouping of ground wires from other romex in the junction box?
 

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A "Handy Husband"
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What is the reason for not connecting the bare wire to the j box/ other grouping of ground wires from other romex in the junction box?
It is aluminum and does not play well with copper. It is not a ground wire it is a bonding wire, its purpose is to insure the integrity of the metal sheath as a ground.

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Red Seal Electrician
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You do not cut off the bare copper bond wire. You wrap it on the green bond screw in the box, and then land it on your receptacle.

This is normal practice with AC cable.
 

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Discussion Starter · #7 ·
What is the best way to handle the bonding wire? I plan to twist it around the outer part of the AC. Should it be under or over the red bushing?

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You do not cut off the bare copper bond wire. You wrap it on the green bond screw in the box, and then land it on your receptacle.

This is normal practice with AC cable.
The bond conductor is aluminum and can either be cut off or wrapped in the spiral under the NEC. The sheath is the ground.
 

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Discussion Starter · #11 ·
Here’s how I plan to use this. Pull the bonding wire back and wrap around the metal sheath. Is it better to go under or over the anti short bushing?

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I liked BX because you could use the bond strip to secure the bushing (over the bushing).
If aluminum is allowed in your city, it's OK.
 

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Discussion Starter · #14 ·
One last question, the rest of my 1929 home is wired with clothe wrapped BX. Way before bonding strips were introduced. What I am finding is a gold colored cap over the end of the BX before the wires exit the metal sheathing.

A few questions-

1) What is this gold cap at the end of the sheathing?

2) I need to eliminate a good section of wire and reconnect in a junction box- is it safe to use a red bushing or do I need to replace this gold cap?

Thanks!

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Discussion Starter · #16 ·
It’s actually fairly easy to clean up and strip, here’s an example of some that I cleaned up. I just need to go back and add red bushings. I’m just wondering what that gold looking cap was that I assumed is a bushing. Am I safe replacing it with a red plastic bushing?

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Red Seal Electrician
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Sorry, I assumed it was oxidized copper, not aluminum. Learned something new.... still - Lol.

Our '93 vintage AC90 would have a bare copper.
 

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A "Handy Husband"
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One last question, the rest of my 1929 home is wired with clothe wrapped BX. Way before bonding strips were introduced. What I am finding is a gold colored cap over the end of the BX before the wires exit the metal sheathing.

A few questions-

1) What is this gold cap at the end of the sheathing?

2) I need to eliminate a good section of wire and reconnect in a junction box- is it safe to use a red bushing or do I need to replace this gold cap?

Thanks!

View attachment 658689
I have seen some of those gold caps on renovation work I did back in the late 50s (I was in high school). It served the same purpose as the fiber red heads we were using at the time. Fiber red heads were later changed to plastic.

You should know that old BX is an ungrounded cable and it is non compliant to extend or modify its use.

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Discussion Starter · #19 ·
The only way to not bury a box in the wall would be to cut the span out and reconnect in an exposed basement ceiling junction box. I don’t want to bury any boxes and would rather reconnect in the basement. Is the ungrounded BX a huge issue? There’s no way to get around not using it.
 

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Discussion Starter · #20 · (Edited)
Lastly, any concerns with my 1920s wire inside the BX? At first I thought it was aluminum however I noticed when cutting one the center is copper. I then realized the entire wire is copper after scraping with a razor blade. See photo of scrap piece.
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