# Ground wire connections in metal junction box.



## Jim F (Mar 4, 2010)

Currently reworking wires and adding new circuits. Upon opening junction boxes in my basement I found the bare ground wires connected to the metal box itself. Is this proper, or should the be pigtailed inside the box? Or is it just a matter of preference? I have googled this question and just kept getting directed to recepticle boxes.


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## jbfan (Jul 1, 2004)

Both! All grounds should be tied together, and bonded to the metal box.


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## Jim F (Mar 4, 2010)

How best to bond the ground wires to the box?


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## jbfan (Jul 1, 2004)

Add a short pigtail, and there should be a 10/32 screw hole to attach the bond wire to.
You can also buy bond wires with the screw attached.


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## jamiedolan (Sep 2, 2008)

Old style for grounding, your box could look something like this, this isn't allowed anymore.










Current method, using a green grounding screw.


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## Jim F (Mar 4, 2010)

Yup, I'll be redoing those before they get hooked up.


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## frenchelectrican (Apr 12, 2006)

The photo what Jamie show that is correct way with 10-32 screw in there and that is is proper way to bond it and it work the best that way.

I have done the same thing with older box however some older box you may hit 10-24 screw which I have ran into once a while so expect that.

It will take couple extra minuites and also get few green wirenuts as well some area you will need it anyway. { espcally with new boxes you will have to do that }

Merci.
Marc


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## AllanJ (Nov 24, 2007)

I don't see the difference between the "old" method and the "current" method pictured above.


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## jamiedolan (Sep 2, 2008)

AllanJ said:


> I don't see the difference between the "old" method and the "current" method pictured above.


In the older versions of the code, you could just tie the ground wires around a screw in the box, such as the 8-32 that is commonly inside boxes to tighten down as a romex clamp.

Now you need to use a Green Grounding screw that is seperate from the other romex clamp screw. It is a 10-32 screw that is made for holding the grounding wire. Many boxes already have the 10-32 holes, though I have seen older ones that don't and I tap them out. I have a Klein Hand tap that is handy, it goes up from 6-32 to 8-32 to 10-32.


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## frenchelectrican (Apr 12, 2006)

AllanJ said:


> I don't see the difference between the "old" method and the "current" method pictured above.


I am gald you ask that part of course I have see some old methold which they wrapped around the screw as Jaime's first photo more than half of my time I find them allready loose or not really bonded very well.

{this part is very common to find grounding conductor are pretty short on old methold so have to add a pigtail ( two peices or one long one depending on the set up ) }

And when I switch over from old two slot receptale (1-15R)to new three slot receptale(5-15R) I have to extend the grounding conductor many time which it pretty common and few case it get tricky to get the grounding conductor out due some case they cut off right before they get into the junction box.

If that the case then I have to use the new 1-15R { old two slot style } I know few people asked me to run new grounding conductor to the water pipe { this part I stay away for good reason just go direct to the load centré. }

Basically I do not run new circuit on old ungrounding circuits

or run GFCI sans grounding and put up the sticker say No grounding exsting.{ very limit use on this one}

Merci.
Marc


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## jbfan (Jul 1, 2004)

The screw does not have to be green!


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## jamiedolan (Sep 2, 2008)

jbfan said:


> The screw does not have to be green!


:laughing: I've only ever seen them in green, so I just got used to calling them the Green Grounding Screw.


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## frenchelectrican (Apr 12, 2006)

jbfan said:


> The screw does not have to be green!


I am pretty sure the NEC did not mention about that but in French codes it have to be green.

Merci.
Marc


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## Jim F (Mar 4, 2010)

I've seen those groud wire nuts now I know what they are for. And, there's even a special grounding screw. the question came up in my mand as I was doing it now I'm glad I asked.


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## J. V. (Jun 1, 2007)

AllanJ said:


> I don't see the difference between the "old" method and the "current" method pictured above.





jbfan said:


> The screw does not have to be green!





frenchelectrican said:


> I am pretty sure the NEC did not mention about that but in French codes it have to be green.
> 
> Merci.
> Marc



*250.148 Continuity and Attachment of Equipment
Grounding Conductors to Boxes.*

(C) Metal Boxes. A connection shall be made between the
one or more equipment grounding conductors and a metal
box by means of a *grounding screw that shall be used for
no other purpose,* equipment listed for grounding, or a
listed grounding device.

I am of the opinion the screw does have to be green, since all the ground screws that are listed for the purpose are green. 
Any 10/32 machine screw the way I see it would be a violation.


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## frenchelectrican (Apr 12, 2006)

J. V. said:


> *250.148 Continuity and Attachment of Equipment
> Grounding Conductors to Boxes.*
> 
> (C) Metal Boxes. A connection shall be made between the
> ...


Not quite but with standard machine screw as long you have at least two threads in the box you are allright but JAMAIS { NEVER } use the self tappers the thread is way too course unless you have self tapping *machine* screws.

I know majtory of the inspector are used to see the green grounding screw but few case some don't I know few Canadian boxes I have see they are not green unless you got the modern one which I did see it few time when I was living in Québec for while.

Merci.
Marc


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## J. V. (Jun 1, 2007)

frenchelectrican said:


> Not quite but with standard machine screw as long you have at least two threads in the box you are allright but JAMAIS { NEVER } use the self tappers the thread is way too course unless you have self tapping *machine* screws.
> 
> I know majtory of the inspector are used to see the green grounding screw but few case some don't I know few Canadian boxes I have see they are not green unless you got the modern one which I did see it few time when I was living in Québec for while.
> 
> ...


The screw must be listed for the purpose. The only screws I know of that are rated for this purpose are green.
So, I must disagree with you on the color and agree it must engage at least two threads in addition to being green in color.


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