Attaching a grounding lug

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donselec

donselec

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Location
Aurora, CO, USA
I had a 6 X 6 X 4 steel junction box for branch circuit wiring, and attached a grounding lug using a self-tapping sms. I've done this for years but this time the isnspector rejected it, and I can see from 250.8 that he's right. But how should you attach the lug? I've used a nut & bolt before and that's always passed. Of course I wire brush off the paint where the lug attaches. Any other ideas? Thx.
 
You really need to get you a Greenlee DTAPKIT:

799-0019.jpg
 
The nut & bolt sounds best, but is it legal, or do you have to do a threaded hole like Marc suggests? 250.8 is a little vague even in the Handbook (2005). It's only a #10 CU gr., max branch circuit size is 30A. The box doesn't have a manufactured place for a grounding screw. Thx again.
 
Anything besides a sheet metal screw is fine with the NEC. Railroad spike, rivet, drywall screw, tapped hole, nut and bolt, etc.
 
Since you already had a hole in the box I would just use a three way tap and keep going until you get the right sized hole.
 
infinity said:
Since you already had a hole in the box I would just use a three way tap and keep going until you get the right sized hole.
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...and if you do it enough, the other two taps will eventually break off :mad:
I have a few 4-in-1 taps (they were 6-in-1's).....they do come in handy under the right conditions:wink:
 
I think a railroad spike might be a little to large for a 6x6x4 can. I just tap a 10-32 into somthing that size ''30 amp" or smaller. Nut and bolt is solid though.
 
I think I'll use a 10-32 nut & bolt. Trouble with tapping, it's mounted on a brick wall. I can use the n & b on the bottom or side. Railroad spikes? Man, let's not get violent. :smile: Thanks. :smile:
 
acrwc10 said:
I think a railroad spike might be a little to large for a 6x6x4 can.
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Don't knock it until you've tried it.

Railroad spikes have lots of other usefull purposes:
Flat tire maker:
100_5266b.jpg


Dragon fly:
COS_Spike_1.jpg

A knife:
Rspike2.jpg




You just have to use your imagination...

...but this guy may have "enhanced" his imagination:
donley02.jpg
 
I started using the greenlee tap/drill earlier this year and was skeptical. They work great and save a lot of time, but, using tapping oil or you will break it.
One tool now does the work of three - center punch, tap drill, and tap.

For the nut and bolt type, try some kep nuts, they have a captive star washer and the nut holds its self. I have in 4 or five sizes.
 
mdshunk said:
Fancy and fragile? This, coming from the guy with the custom engraved no-dog? :grin:
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LOL :grin: DOH!

OK you got me, they are fancy....not so fragile.

The engraving only cost $1.
 
Taps, Drills, Hole Hawgs...................always the hard way.

Get out your trusty MIG welder, Arc a lug to the side of the can and call it a day.

If your doing this in the winter use an Oxy-Acetylene torch with a brazing rod to attach the lug. It will serve two purposes............it will clean the paint off and it will also keep you warm.
 
mdshunk said:
You really need to get you a Greenlee DTAPKIT:

799-0019.jpg
Click to expand...


It doesn't take reading too many of my posts to realize how much I love these things. The 10-32 is probably my fave because of the fine thred.

Celtic, it seems you are the internet search king when it comes obscure references to wandering posts. Great. :grin:
 
donselec said:
I had a 6 X 6 X 4 steel junction box for branch circuit wiring, and attached a grounding lug using a self-tapping sms. I've done this for years but this time the isnspector rejected it, and I can see from 250.8 that he's right. But how should you attach the lug? I've used a nut & bolt before and that's always passed. Of course I wire brush off the paint where the lug attaches. Any other ideas? Thx.
Click to expand...

I don't see how this is prohibited by 250.8. A self tapping screw is not a sheet metal screw.
 
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