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GREEN GROUND SCREW

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HI MIKE I HAVE A QUESTION. IS A GREEN GROUND SCREW MANDATORY FOR BONDING A RECEPTACLE TO A METAL BOX OR ARE THERE OTHER MEANS THAT I CAN USE? GIVE ME A SECTION IN THE CODE OR OTHER APPROVED WAYS THANK YOU

[ October 25, 2003, 02:46 PM: Message edited by: littlerich ]
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: GREEN GROUND SCREW

250.148(A) permits the use of a "grounding screw that shall be used for no other purpose or a listed grounding device" to bond the EGC to a box. In my opinion, the "grounding screw" is not required to be green. 250.8 says you can't use a sheet metal screw for the connection. Some code experts say that 250.8 requires the use of "listed" products for all grounding connections.
Don
 

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
Re: GREEN GROUND SCREW

I agree with Don. We get the impression the green machine screw is required, however that requirement is for the receptacle bonding screw.
The grounding pigtails come with a green 10-32 machine screw, so in many ways that becomes the de facto standard.
 
Re: GREEN GROUND SCREW

CAN I USE A 1/4 INCH NUT AND BOLT AND A RINGED 1/4 INCH STACON TO ATTACH THE #12 GREEN THHN TO THE BOX. THE BOX IS 4 X 2 1/8 DEEP. DO I HAVE TO MAKE THE BOLT GREEN OR CAN I LEAVE IT ALONE?
 

pierre

Senior Member
Re: GREEN GROUND SCREW

There you go Ryan, 'Don't Sweat the Small Stuff for Electricians'. A new tittle for the stressed in our industry. I can see a best seller or is that cellar soon to be at book stores everywhere :D

Pierre
 

jro

Senior Member
Re: GREEN GROUND SCREW

Littlerich would'nt it be easier to use a green ground screw with a green pigtail in this application, just my opinion, also read 250.126 (1, (2), and (3).
 

ryan_618

Senior Member
Re: GREEN GROUND SCREW

Originally posted by jro:
Littlerich would'nt it be easier to use a green ground screw with a green pigtail in this application, just my opinion, also read 250.126 (1, (2), and (3).
250.126 doesn't apply. I don't think that bonding the box is a "wiring device terminal".

[ October 27, 2003, 06:47 PM: Message edited by: ryan_618 ]
 

jro

Senior Member
Re: GREEN GROUND SCREW

How is it that 250.126 does not apply, what are you talking about. So I should go into my materials bins and throw away all my green ground screws, green pigtails, green tape, green ground wire, green ground clips, etc. I think Bennie is right, the code should be written in every day language EXAMPLE: "The ground screw shall be green, and if you the electrician uses any other screw that is not green you will not pass inspection" and all this confusion will just go away.
 

ryan_618

Senior Member
Re: GREEN GROUND SCREW

I'm just going off of the definition of "device". I don't beleive that a box is a device, as defined. The device terminal is already green...it is on the receptacle.

No need to get upset, just my opinion.
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: GREEN GROUND SCREW

jro you do not have to throw anything away, but Ryan is correct 250.126 is talking about the grounding screws on devices only.

250.126 Identification of Wiring Device Terminals.
A box is not a device as defined by article 100.

Device. A unit of an electrical system that is intended to carry but not utilize electric energy.
You may use a nut and bolt to connect the grounding conductor to an enclosure and it does not have to be green.

Often I need to land a large conductor to an enclosure by means of a lug held on to the enclosure with a nut and bolt, would you expect that to be green.

I think the intent of 250.126 is to make sure the grounding terminal on a device can not be mistaken.

What mistake is possible when grounding a box?
 

jro

Senior Member
Re: GREEN GROUND SCREW

Too late Iwire all my green material is sinking to the bottom of the Trinity River, I wish you would have posted earlier :mad: I'm mad at myself $$$$$$$$$$$$$ money down river, but I still stand by Bennie, simple is better, when landing a large ground wire, you are still required to ID the wire with green tape, but the poster was talking about bonding a receptacle, to a box, I say the screw has to be green, and the green screw is listed for such an installation, other wise what is the use in all the materails I listed.
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: GREEN GROUND SCREW

Well you can always use the green screws and mostly I do as they are conveniently provided with a green wire hanging off them. :)

My point was this, think of a female cord cap if 250.126 did not require the grounding terminal to be clearly marked someone could mistakenly land a hot on the grounding terminal.

If this was done whatever got plugged into this cord cap would have a hot case, very dangerous I think we would all say. :eek:

But in the case of a box ground how does the green screw enhance safety.

Is someone going to see a bare or green wire terminated to an enclosure as anything but a ground wire.

I say the screw has to be green, and the green screw is listed for such an installation
Do you have a code article to back that up?

250.126 is not applicable to anything but devices.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: GREEN GROUND SCREW

jro
other wise what is the use in all the materails I listed.
To make money for the people who make and sell those products and to make your job easier. The use of a green screw at the connection to the box is not required by the code. If only "listed" screws can be used for connecting grounding conductors, then how can we connect large ground wires. The only listed green screws are 10-32. Not very effective for terminating 500 kcmil.
Don
 

jro

Senior Member
Re: GREEN GROUND SCREW

I have come across grounds terminated under a 1/4-20 bolt, not the ideal way, as for 500 kcmil you still have to use a listed product to terminate any large wire, and it would be much easier to use a listed pigtail with green ground screw, to bond the receptacle to the box, the object of contracting is to make a profit, it makes more sense to use pigtails w/screws, not to mention it would be less time consuming and cheaper, than it would be to use 1/4-20 bolts and nuts, especially if we are talking more than one receptacle. So what is a grounding screw, any screw, 8/32, 6/32 etc, as long as it is used for that purpose only, I would much rather use a listed product that would insure a good connection, try putting a green #12 thhn stranded under a 8/32, not good, and some electricians will do it. That is why I say in the case of bonding a recptacle to a box, a listed green wire and screw is my choice.

[ October 28, 2003, 10:08 PM: Message edited by: jro ]
 

ryan_618

Senior Member
Re: GREEN GROUND SCREW

Jro: Nobody is arguing that your method is not a good or legal or proper method, it is just not the only method permitted.

The screw does not need to be green.
 

ryan_618

Senior Member
Re: GREEN GROUND SCREW

I'm going to join the dark side and agree with Don about the terms bonding and grounding!!!

A "ground screw", in my opinion, is one that connects to a box, or it can be one that perhaps connects a lug to an enclosure.
 
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