Torqueing down Wirenuts Hard

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  #1  
Old 11-23-13, 10:33 AM
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Torqueing down Wirenuts Hard

My intentions not to start another pretwist vs. no pretwist debate (although it might be hard not to consider that too here).

I was wondering how tight is tight with a nut?

Are you supposed to reef down on the nut until it will not turn anymore?

Ive been twisting hard.... to the point my fingers hurt.

When I cant get it to turn anymore without twisting the insulated portion below the skirt I stop (let my fingers rest) and then give it another few turns allowing the wires to twist below the skirt. I end up with 3 twists of the visable insulated portion below the skirt.

Can they be overtightened/ stripped? Could there be damage under the nut that cant be seen until a catastrophic failure of the wirenut?

Whats your technique for proper torque (by hand)?
 
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Old 11-23-13, 10:37 AM
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I think this is a matter of opinion.
I was trained under the idea "a good joint should never come apart" and told to pretwist, hand tighten as much as I could, then take my linesmans and tighten even more so it could not be undone by hands which did not belong to the Hulk.
 
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Old 11-23-13, 11:01 AM
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I don't pre-twist unless the existing wires were already done that way. I normally tighten the nut until the wires outside the nut start to twist as well. I never use any tools to tighten, though I guess with larger than 12ga I might, to ensure the spring gets a good bite.

Also, nuts with the wings are much easier to get tight, though I'll probably never buy any again. I must have a couple of hundred of the 3 sizes I'd use. I don't do that much electrical anyway.
 
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Old 11-23-13, 11:14 AM
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I pre-twist wires with my linesmen pliers, then tighten as tight as I can with my hands (without pain). I do not tighten the nuts with any tool.
 
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Old 11-23-13, 11:51 AM
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Do you think a wirenut could be over torqued?
 
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Old 11-23-13, 11:52 AM
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Over at a Pro electricians Forum, they talked about nuts being tightened so much that the wire broke through the end. I'd call that too tight...lol.
 
  #7  
Old 11-23-13, 05:03 PM
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I contend that yes, it is possible to overtorque a wire nut.

Depending on exactly how the wire nut is constructed and the number and thickness of the wires you put inside, the reason for failure could vary, but the typical symptom of failure is the wire nut all of a sudden twisting and spinning free and unable to get tight again. Kinda like a screw stripping its threads.
 
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Old 11-23-13, 09:45 PM
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Yes....I have seen the wires come thru the end too.

I always twist my wires first before putting on a wirenut. I believe that the twist is what makes a good connection.... not the wirenut.
There is no need to use a tool to put on a wirenut... hand tight is all that is required.
 
  #9  
Old 11-24-13, 05:03 AM
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As far as my electrical experience goes, I am at the DIY level. I don't pretwist my wires and use only my hand to tighten the wire nuts. I have overtightened them to the point they come through the end. The proper torque on the wire nut will twist the wires together. When the insulated part starts to twist, that is a good indication you have gotten things right. After I get my wire nut on, I like to tug on the wires to make sure none are loose. Especially when I have more than two in the nut.
 
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Old 11-24-13, 11:39 AM
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I twist solid conductors and don't twist stranded conductors or a stranded-to-solid splice. Only good twisting with lineman's pliers makes a reliable splice of solid conductors, IMO (and the opinion of the inspectors here).

As for how hard to tighten the wire nut, I just stop when the wire nut stops turning by hand.

We sometimes tell apprentices who are struggling with getting everything to hold together to tighten a wire nut until it fails, then replace it.
 
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Old 11-24-13, 12:57 PM
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You want to struggle...... in commercial installations if the wiring run is more than 100' from the panel you have to upsize from #12 to # 10. Splicing #10's is a real treat in a 1900 box.
 
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Old 11-24-13, 01:16 PM
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in commercial installations if the wiring run is more than 100' from the panel you have to upsize from #12 to # 10. Splicing #10's is a real treat in a 1900 box.
Been there done that. That's true in residential jobs too, AFAIK, It's just that you seldom run into runs that long there.
 
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Old 11-24-13, 01:40 PM
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PJ,

Even splicing 10's in an o-box for exits (ac + dc lines) is a treat.
 
  #14  
Old 11-24-13, 02:12 PM
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What would be a typical way a wirenut connection would fail. Would it all of a sudden catastrophically fail... melt. Or would it be a progressive thing with warning signs like intermittent power or voltage drop etc..
?
 
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Old 11-24-13, 02:29 PM
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Depends on how loose it was and if the connection between the wires was also loose. I have seen the melted plastic with the spring almost floating on the connection. If one conductor is loose you might have intermitent issues. I had another where the ambient temperature affected the connection.
 
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Old 11-25-13, 12:05 PM
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The ideal brand "wing twist" brand nuts I have been using call for 3/8" stripped for the yellow and 1/2" for the reds. I assume thats what other nuts call for as well. When I strip 3/8" for the nut I think to myself how small that really looks....

How is that enough surface area to make a reliable connection? Esp. when your talking about 4 or more wires under a nut..... Is the spring in the nut designed to be a conductor or just there for mechanical pressure?
 
  #17  
Old 11-25-13, 12:11 PM
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Anything more and you will have bare wire sticking out of the nut. Remember, the wires twist around each other when you put the wire nut tight enough.
 
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Old 11-25-13, 01:39 PM
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The strip length is how the nuts were tested and listed for use. The spring supplies pressure along with being conductive.
 
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Old 11-30-13, 05:25 PM
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How about reusing wirenuts? Is that bad?

For example you remove the nut to test.

Today I removed a nut, the wires were nicely twisted. However, I used a new, different wirenut to recap it..... did I make a mistake?
 
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Old 11-30-13, 05:53 PM
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If I take them off with my hand then I'll reuse them.
If I have to use pliers to get it off...... it's scrap.
 
  #21  
Old 11-30-13, 06:04 PM
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Is the spring in the nut designed to be a conductor or just there for mechanical pressure?
The spring is normally zinc plated steel and is primarily for applying mechanical pressure on the splice.

Here is a handy little tool for when your teenage son breaks your hand and you have a houseful of wirenuts to install the next day. I've had a 7-in-1 screwdriver with the "Twist-a-Nut" feature in the handle for 7 or 8 years, but it's still in the package. I'll try it one of these days.

http://www.idealindustries.com/media...t_brochure.pdf
 
  #22  
Old 12-01-13, 01:01 PM
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Do you guys usually max out the number of wires allowed?

Ive been putting 3x#14 in yellow ideal wingtwists. The directions say thats the max.

Is maxing it out pushing it or any less secure then being well under the max??
 
  #23  
Old 12-01-13, 01:20 PM
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I, personally, don't go by the manufacturers instructions. I make the splice up and based on how neat it is and how much insulation is exposed I choose an appropriate wire nut. Sometimes on three #14's I'll use a yellow and sometimes I'll use a red.
 
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Old 12-01-13, 01:46 PM
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As long as the number and gauge of the wires are within the listed size range of the connector you should be fine. They are tested in those combinations.
 
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Old 12-01-13, 02:30 PM
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I, personally, don't go by the manufacturers instructions. I make the splice up and based on how neat it is and how much insulation is exposed I choose an appropriate wire nut. Sometimes on three #14's I'll use a yellow and sometimes I'll use a red.
Ive been following them by the letter. For 3 #14 in the yellow nut I assure that I only have 3/8" of insulation off etc.

3 #14 with only 3/8" of insulation removed, is that adaquete for a good connection in your own experience working with these materials?
 
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Old 12-02-13, 07:25 AM
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Ive been following them by the letter. For 3 #14 in the yellow nut I assure that I only have 3/8" of insulation off etc.

3 #14 with only 3/8" of insulation removed, is that adaquete for a good connection in your own experience working with these materials?
I never measure the amount of exposed conductor for a splice. I strip more than enough, line the wires up with the ends of the insulation even, and twist them. Then I eyeball the result, choose a wire nut, and give the splice a haircut to fit it. My goal is to have the wire nut screw on completely (without being stopped by the insulation) and have no bare conductor near the edge of the wire nut's skirt.

Remember that a day's work can include doing 300 or more of these for many of us. We've learned to do it by feel. But the process and the checks I noted above are what make it work.
 
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