Twisting ground wires in romex

[LarryFine]

Twisting the EGCs together with out any type of connection device was very common in this area when I started. Most of them would have about 2" of the EGCs twisted tightly together and tucked in the back of the box.

While a code violation, I really doubt that anything less than the most sensitive lab meter would show any difference between the twisted only installation and one using a wirenut or a crimp.

Until one breaks. I had a customer complain of getting shocked in the bathrooms. To make a long story short, I found a 2-gang box where the EGC of the incoming NM cable broke where the sheath was stripped.

That one conductor spun around on the twisted bundle until the tip of it touched a screw terminal on one of the switches, energizing the entire EGC system downstream of that box, including the bathroom switches.

 

[don_resqcapt19]

Until one breaks. I had a customer complain of getting shocked in the bathrooms. To make a long story short, I found a 2-gang box where the EGC of the incoming NM cable broke where the sheath was stripped.

That one conductor spun around on the twisted bundle until the tip of it touched a screw terminal on one of the switches, energizing the entire EGC system downstream of that box, including the bathroom switches.

I don't see were the use of a crimp or a wirenut would make any difference in the breakage of a conductor.

 

[LarryFine]

I don't see were the use of a crimp or a wirenut would make any difference in the breakage of a conductor.

No, but, while I realize my example was a freak accident, a wirenut or crimp, while not preventing the break, would have prevented the accidental contact and energization.

 

[readydave8]

Twisting the EGCs together with out any type of connection device was very common in this area when I started. Most of them would have about 2" of the EGCs twisted tightly together and tucked in the back of the box.

While a code violation, I really doubt that anything less than the most sensitive lab meter would show any difference between the twisted only installation and one using a wirenut or a crimp.

I have seen many hot and many neutrals twisted together and taped, no wire nut or crimp. They usually strip and twist longer than if using a wire nut, and twist tightly with pliers.

I've pulled tape off these looking for open or intermittent open, and have seen several that looked twisted tight, I felt like they probably were tight on the original install, but not making a good electrical connection, I could grab them with pliers and make them arc.

My question is: is this condition caused by heating and cooling of current-carrying conducters? Or would normal changes in temperature, vibration, etc., cause the same problem on bare grounds? The difference being that the user is more likely to notice a light flickering or not working than he would a loose ground.

 

[kwired]

That may well be what he ment. In this area ( county ) they do want crimps and not wire nuts for residential work.

Some jurisdictions will accept wire nuts and others will not. I know what the code says but never forget that if you have to work in a jurisdiction some things are just not worth fighting over.

I use crimp connectors for grounds because they are acceptable in all jurisdictions where I work and it's not that big of a deal.

In one jurisdiction I use to work in if it was NM you had to use green wire nuts.

There are some real dumbasses with more power than they should ever be trusted with. :roll:

electricmanscott is absolutely correct.

There are other possible ways to make up the grounds that have not been mentioned, how can a jurisdiction say that only green wire nuts or only crimp connectores are allowed?

One could use Wago's, wirenuts that are not green, terminal strip, polaris connectors, split bolts, multi hole lugs, terminal bar, screws in tapped holes in metal boxes with the ground wire(s) terminated under the screw(s) (and they don't have to be green either), grounding clips on metal boxes, solder connections, cadweld, there may be a few other ways.

These are all approved ways that it may be done although not all of them are practical or would fit in some boxes.

 

[Mgraw]

electricmanscott is absolutely correct.

There are other possible ways to make up the grounds that have not been mentioned, how can a jurisdiction say that only green wire nuts or only crimp connectores are allowed?

Before 2007 it was very easy for a jurisdiction to pass whatever they wanted. Many would pass simple things just to keep "outsiders" out, or if they did get a license a way to make things more difficult for them. One juridiction required HVAC guys to have a gas license to work on or install gas furnaces. No other jurisdiction required this so it kept all the "outsiders" out.
In one jurisdiction, on residential, the GEC had to go from the water line to the rod then the panel then to any grounding bushings then end in the meter socket. One continuous wire. They would give out rejections and then it could take a week for a re-inspection.

 

[mivey]

That may well be what he ment. In this area ( county ) they do want crimps and not wire nuts for residential work.

Some jurisdictions will accept wire nuts and others will not. I know what the code says but never forget that if you have to work in a jurisdiction some things are just not worth fighting over.

I use crimp connectors for grounds because they are acceptable in all jurisdictions where I work and it's not that big of a deal.

Sounds like we might have mowed some of the same grass. I used only crimp sleeves on the grounds for years. I hate having to take them off for changes. But, you are right: Pick your battles.