ECN Forum Forums Code Related Discussion NEC & other Code issues Need opinion

We are talking about a Direct connection of a screw to Equipment grounding conductor with box clamp screws, As far as a LUG to an equipment grounding conductor common sense says a Good connection made by a 1/4 20 ect done right well be code compliant. This started off as a simple question then guys started adding lugs ect Question Was an Equipment ground wire being hooked to a cable box clamp Screw , not a metal box , not a ground bar ect. Its not only a matter of the code to me but proper workmenship .Otherwise just grab any screw in any box hook the gr. wire to it!!I say again the Head on a box clamp screw to to small , Believe me been in the trade a long time i tried it.

Guys,
I'll take the clamp screw over the listed push on grounding clip every time. Yes, the head is a bit smaller than the green screw, but it is plenty big enough to secure #12 or #14 to the box.
Don

I don't know how much old work some of you guys have done,I myself have done every much.
When NM was first made with an equip. grd. how do you think the box was bonded?,WITH THE CLAMP SCREW!, cause there was no threaded hole for a ground screw! Hell the screw on the RX conn was also a very common method.

I remember when tapping on to knob and tube we used 12-2 without gr. also. I also remember when the equipment gr. in 12-2 was a # 14, BUT that was then and This is now. AAAAAAA the days of pulling solid tw , Things are better now so should the craftmanship.Most jounreyman back then had Never even seen a code book.Back then 314.40d was not in the code book all new boxes ul listed or labeled well have a tapped hole for the gr. screw old boxes I;m sure from stock do not.

Yoopersup,
If you are talking about landing a stranded EGC to the box, I wouldn't land that directly to a screw, even a green one. I still have no problem using the clamp screw, with the clamp removed, for landing a solid equipment grounding conductor.
don

I did an inspection today on this very thing. The electrician had used a green 10-32 for the bonding and therefore I passed it. Right next to it was the clamp, and guess what...the clamp screw was bigger!!!!

I'll post a picture tommorrow.

Ryan, I see some clamp screws that are bigger also. I checked my box of ground screws today. No UL listing on them. And no manufacturers instructions. A 10/32 is a 10/32 that simple!

I put a demonstration together.

The first two pictures show both methods.




Can anyone tell me why the 'green' screw is any better than the clamp screw?

Someone also asked Don why he takes the clamp out, well I do too and I think this picture illustrates why.



If there is going to be a short in a box with MC clamps it will be where the wires are pushing against the top of the extra clamp. Take that clamp out and there is much more room.

I had to use a wire nut on the box with the grounding pigtail as it is almost imposable to wrap the incoming ground wire around the screw due to the small space.

I consider myself a craftsman, I take pride in my job and I respect the code.

George's original post.


The answer is there is nothing in the NEC that prohibits what the contractor is doing as long as the clamp is removed from the screw.

It's that simple.

JMO, Bob

Well done Bob.

A picture is worth a thousand words as the saying goes. I do see your point for what you've done. I wonder if the box fill allowance has been violated? If you used #12 AWG we would need 13.5 cubic inches. Looks crowded even using the clamp screw hole. Check your box fill, use a green screw in the clamp screw hole, recall the inspection for tomorrow and I'll approve it:-))