Electrical Panel update New house

[MikeB44]

To Pretwist or not to Pretwist, here’s my 2 cents. (Probably not worth that much).

Dad & I wired a few fans for Alan this past weekend. The ceiling boxes had pretwisted wires and wire nuts, without tape. I was happy to see the wires pretwisted, as they all still had a tight connection.

I had 2 years of industrial wiring training in high school and was taught (by a Mr. Jones) to pretwist the wires with linemens pliers, install a wire nut, test the mechanical strength of each wire by tugging on it, and then tape if desired. Mr. Jones explanation to us as to why to do this was the following:

1. Pretwisting provides a strong mechanical connection that keeps the wires from separating (if a wire gets pulled or pushed when being pushed back into the box).
2. Pretwisting creates a better electrical bond between the wires, (one wire’s surface area to another wire’s surface area)
3. Tugging on the wires tests the wire nut assembly by simulating some of the force of putting the wires back into the box (and possibly taking them back out again). This force can be considerable, especially if there are a number of wires held together by a wire nut that need to be pushed back into the box. If a wire comes loose during this, redo the connection and test again.
4. Taping is done more to protect something coming in contact with the bare wire under the wire nut, but it can also help the wire nut from unscrewing during the process of pushing the wires back into the box. (Note that ideally the copper wire should not be visible outside the wire nut and also the insulation should not be into the steel “teeth” of the wire nut.)

I do not remember my Dad pretwisting wires as an electrician. I do remember showing him what I learned in school and he said that sounded like a good reason to do it. He & Mom built a number of houses when they were younger, and all are still standing. I assume that he did these without pretwisting the wires.

It has become natural & much faster for me to pretwist the wire with linemens pliers. I recognize it as something that not everyone does, but in my opinion should do (similar to hooking wires under switch/outlet screws rather than using tension hold inserts in the back of the devices). Since codes allow for it, either way is acceptable – for me pretwisting is the only acceptable way for my work (all because of Mr. Jones answering the “Why?” for me.)

Note: I am not an expert, I just do this at home (or invited homes).

Also Note: I have not redone all the boxes in my house this way. Just the ones that I have had to work on…

 

[Kendall69]

I'm a bit more ****. I pretwist, then trim so each wire is the exact same length, then I put on the wire nut, lastly I tape. Heck in some cases I even solder before the cap if I know the connection will never have be undone.

 

[Diesel-ME]

I pre-twist when the number of wires is under the nut capacity and not when maxed out - in which case I always wrap with tape. I tend to twist when a conection is going to be pushed back in a "busy" box. I crimp grounds in a loaded up work box to save a little space.

My $.02

~paul

 

[hudlow]

Youy guys talking about stranded wire or solid?

Most industrial electrical jobs I worked on used the crimps and rubber sleeves, or diapers as we called them. We didn't twist the wires before crimping the sleeve on. After the crimp was made with our Sta-Kon pliers we trimmed the ends and wrapped it with a diaper. This was mostly stranded wire.

But when I'm using wire nuts with solid wire I lay all my wires together neatly, ends trimmed to same length and use the correct sized wire nuts to make the mechanical connection. If the wires are pre twisted before inserting them in the nut there's a chance that one of them may not get inserted all the way in as deeply as the rest and this wire could become loose and create a problem with an arc or some other undesireable situation, in my opinion.

I've seen it done every way imagineable and heard most every opinion. The way I described above is how make my connections.

About the only exception is when I am joining a stranded wire to a solid wire. Then I'll let the stranded wire extend slightly longer than the solid wire before I put the nut on and make the twist. It seems to make a strondger connection that way.

hud

 

[BTDT]

If your going to twist, be sure to twist in the right direction...If you twist to the left, wire nut goes on to right..problem.

 

[MikeB44]

Youy guys talking about stranded wire or solid?

But when I'm using wire nuts with solid wire I lay all my wires together neatly, ends trimmed to same length and use the correct sized wire nuts to make the mechanical connection. If the wires are pre twisted before inserting them in the nut there's a chance that one of them may not get inserted all the way in as deeply as the rest and this wire could become loose and create a problem with an arc or some other undesireable situation, in my opinion.

I've seen it done every way imagineable and heard most every opinion. The way I described above is how make my connections.

About the only exception is when I am joining a stranded wire to a solid wire. Then I'll let the stranded wire extend slightly longer than the solid wire before I put the nut on and make the twist. It seems to make a strondger connection that way.

hud

Hud,

Sorry - I was talking about solid wire. Our training was called "Industrial" because it covered both residential and industrial wiring (we wired motor windings, and such) and they didn't want to confuse it with residential only wiring (I guess).

The method I use is to hold the wires together so that the end of the insulation matches each other (the stripped lengths can be different) and then pretwist with the lineman's pliers. Once the wires are pretwisted, I look to see that the insulation for all the wires stops at the same point and then use the lineman's to trim off the excess stripped length so that the bare copper will be covered by the wirenut. I test the mechanical connection before and after the wire nut is put on.

Your explanation of using stranded wire with solid was very good. I also trim stranded wire longer than the solid and let the extra length "hang over" the end of the solid wire. This let's the solid push the stranded into the end of the wire nut and helps to hold it in place. (Being careful not to cut off the stranded with the solid pushing on - again testing the mechanical connection)

I really think the biggest part of using wirenuts (pretwist or no pretwist) is to be aware that testing the mechanical strength of the connection is important. You want that "good feeling" when you push the wires back into the box that they will stay connected the way they supposed to. Everytime in class (many years ago) that we pushed the wires back in with an expression of "I hope they stay in place", Mr. Jones would come along to inspect and promptly pull out one of the wires.

BTDT - good point! (I always like the sense of humor, mixed with truth, that I read among the posts!)

 

[Farwell]

If your going to twist, be sure to twist in the right direction...If you twist to the left, wire nut goes on to right..problem.

Righty tighty....lefty loosey. Turn to the right and your are right, turn to the left and you are not right! Right?
To twist or not to twist...that is the question.

 

[hudlow]

Righty tighty....lefty loosey.

Two older women called me over to their car next to a gas pump the other day.
They were struggling with the gas cap and wanted me to get it off for them.
I twisted it off and they started goodnaturedly picking at each other because they were arguing about which way to turn the cap.

I told them to remember "righty tighty, lefty loosey" and as I was walking back to my truck these two old girls were chanting ,"righty tighty, lefty loosey
righty tighty, lefty loosey,righty tighty, lefty loosey" and just dying laughing.

It was one of those moments you live for.

hud

 

[silverdollar6]

Four pages on how to use a wire nut,do all of you guys work in an office?

 

[gemini5362]

Four pages on how to use a wire nut,do all of you guys work in an office?

I believe it is called an informative discussion. I have actually learned a lot about how things work by reading some of these discussions.


by the way I dont work in an office I am a maintenance electronic technician at a large corporation.