Proper torquing method

[RichB]

I am sure this has been covered but can't find it,, so,,
When torquing lugs do you go till the wrench clicks then wiggle the conductor and re-torque or stop at the first click.
I was taught and have done the torque wiggle torque, but something is scratching at the back of my head saying that is incorrect.

 

[ptonsparky]

I am sure this has been covered but can't find it,, so,,
When torquing lugs do you go till the wrench clicks then wiggle the conductor and re-torque or stop at the first click.
I was taught and have done the torque wiggle torque, but something is scratching at the back of my head saying that is incorrect.

Some say don't even wiggle. I wiggle the conductor more on the way to torque, than after. Whatever trips your trigger.

 

[RichB]

That's the way I am leaning also---Just getting old with too many things bouncing around in the head--just seemed to remember something about more than once causes an over torque--especially on smaller conductors--

OK No need to worry and no need to change! Thanks!!!

 

[zbang]

To actually "re-torque", you need to loosen the connection and run it up to torque again; torque can only be properly measured when the bolt/screw is moving. If wiggling the wire loosens it then IMHO either the lug has a problem or the measurement wasn't right.

 

[ActionDave]

If that is true then every lug I have ever tightened had a problem.

 

[ptonsparky]

The only ones I couldn't move at some point were lugs that were maxed out with the single wire size. Take into account that I have never been a muscle bond hulk.

 

[winnie]

Not lugs, but with 'set screw wire connectors' sometimes the strands can lay in ways that are not fully compressed.

Tighten the set screw, wiggle the wires, and everything moves just a bit and suddenly the set screw is loose.

It wouldn't surprise me is the same is possible with lugs now and then.

Jon

 

[zbang]

Perhaps a better way to think about is torque, loosen, torque; that should compress the strands into the right place while not over-torquing the bolt.

 

[ptonsparky]

To make it clear, I am talking about landing the wire under the setscrew of the lug. Not bolting a lug to the busbar.

 

[Tulsa Electrician]

Found this

 

[ptonsparky]

Found this

Chit, I can't use my clicking torque wrench.

 

[jaggedben]

I call BS unless someone makes a tool designed to do that.

 

[LarryFine]

I call BS unless someone makes a tool designed to do that.

Why wouldn't a standard bending-beam torque wrench work?

 

[ptonsparky]

Why wouldn't a standard bending-beam torque wrench work?

View attachment 2563462

Reasonably priced. Calibration by owner. No moving parts.

I still have them.

 

[Tulsa Electrician]

Maybe a dial type?
Pretty common and inexpensive.
Then for deep pockets electronic type.

 

[jaggedben]

Never seen those. Okay.

 

[GeorgeB]

I'll drop back to my mechanical work when aluminum was involved; never had any mechanical experience with copper except one standard small (1/4 pipe) washer used to seal gauges. We'd torque to about 80% wiggling anything we could wiggle, then go to 100% and hold for several seconds, I don't remember anything about 5 seconds. This is roughly what is recommended with "alloy" wheels. We found it rare to need "much" motion to get from 80% to 100% and it rarely experienced creep after that if the specs were correct.

Our checks, yes, I know it was technically wrong, was to use the torque wrench and apply specified torque. If the fastener moved, we'd be happy with the additional turning. If it didn't move, we'd be happy it was tight enough. We'd never intentionally exceed specs.

 

[Tulsa Electrician]

My #1 for last year was the one I caught using an impact gun. His comment was it's has a tongue setting. I said you will never work for me go get your foreman.

#10 was a 1/2" drive in lb ft. Nice wrench tough. I ask do you know the difference between lb in and lb ft. He said I don't understand the metric system. I said stop what your doing go get your foreman.

The whole story would just make you all cringe.
Maybe a campfire chat story.

Most in-between (2-9) based the use of Allen wrenches sets and why you don't need a torque wrench of any kind.
So I think OP question is a good one.
I for one glad you ask. Thanks

 

[jimport]

If the torque and loosen and retorque method is used you are torquing on a compressed conductor. I learned to torque once and done. The correct value accounts for any change in the conductors.

 

[Tulsa Electrician]

Good read. Me personally I have different types and sizes, click beam, dial, Long, short arm 1/4" - 1/2" and screw driver. Each has its place and requirements.

Inspecting Electrical Connections for Proper Torque

iaeimagazine.org

This give pause to how many times used, re-used equipment is installed with bad lugs and no good wrench will fix that. You have to look for the signs at removal. This starts with a check of condition.
I teach you cut the wire for salvaged equipment do not unhook it unless I say to after I have checked it. This is where the dial or beam comes in checking where it's at. If the lug is demand to be over tightened or other issues it is scraped and new one installed.
By over tightened I mean to the point of damage to the screw and lug. Once the threads are pulled it will never hold correctly if it ever gets tight to the proper setting. So look for the signs. Listen to what comments the removal electrician says. These are red flags for install.
"Man that lug was tight you should have heard the noise it made as I un did it."
" Do you have an extension handle I can't get it broke loose."
" It felt like I was going to break it when it popped loose."
" I could not get it all the way loose but I got the wire out"
" Why is there compound on the set screw"

Just some examples.