# Main panel w/ ground bar strap



## MDShunk (Jan 7, 2007)

If you have the bond screw in that strap, either bar can be for either thing. Has to do with UL testing and not what a common sense might tell you about how much current can flow on such a connection. 

I wouldn't get too twisted up about it. Murray is a low-end panel, and as such, will have marginal, low-end features. I'm not so sure I'd put the neutral conductor of a 100 amp subfeed breaker on that other bar, due to the "weak link" there, but I'd be hard pressed to tell a guy it was prohibited. I generally try to land the neutrals of the heavy stuff on the bar that has the actual neutral lug for the service conductor on it.


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## volty (Jan 14, 2009)

Shockdoc said:


> I have come across many installations concerning the Murray brand panel with the ground bar on the left side which is linked to the nueteral bar via a ground screw and copper link, I personally do not believe this side bar is intended for grounded conductors but for grounding conductors. I have come across many panels where this bar has been used for grounded conductors and have passed inspection. The green screw (3/8 x 10/32) leads me to believe this is a grounding only bar, any input ?


If the bar is only connected to the grounded conductor via the Main Bonding Jumper, it is not for the grounded conductors.


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## NolaTigaBait (Oct 19, 2008)

I thought that on those panels, you could use the nuetral bar for neutrals only and the ground bar is for ground only. You could put the grounds on the neutral bar also.


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## MDShunk (Jan 7, 2007)

NolaTigaBait said:


> I thought that on those panels, you could use the nuetral bar for neutrals only and the ground bar is for ground only. You could put the grounds on the neutral bar also.


You probably SHOULD, but it's not required. UL 67 requires that any factory installed or supplied MBJ on equipment labeled as "suitable for use as service equipment" be able to carry the full current the panel is rated for. As such, you can compliantly terminate your neutrals on that remote bar. If you supplied your own MBJ, like you might do on a bigger switchboard or MDP, then you can't, because you'd be sizing it to a different set of rules.


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## volty (Jan 14, 2009)

MDShunk said:


> You probably SHOULD, but it's not required. UL 67 requires that any factory installed or supplied MBJ on equipment labeled as "suitable for use as service equipment" be able to carry the full current the panel is rated for. As such, you can compliantly terminate your neutrals on that remote bar. If you supplied your own MBJ, like you might do on a bigger switchboard or MDP, then you can't, because you'd be sizing it to a different set of rules.


Haven't read the text of UL 67, but hard to imagine a 10-32 treaded screw serving as a MBJ rated to carry, say, 200 amps. Rated to carry enough to operate the OCP, sure, but that would be comparable to a #4 cu, not a 3/0.


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## MDShunk (Jan 7, 2007)

volty said:


> Haven't read the text of UL 67, but hard to imagine a 10-32 treaded screw serving as a MBJ rated to carry, say, 200 amps. Rated to carry enough to operate the OCP, sure, but that would be comparable to a #4 cu, not a 3/0.


I don't like it either, but that's what it says. I guess they're testing these things at the UL. After all, lugs are often only held on transformers by 1/4-20's, and carry hundreds of amps, but you've got extra metal to metal contact with the lug tang on the winding tang.


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## volty (Jan 14, 2009)

I might not be picturing this properly.


Shockdoc said:


> Murray brand panel with the ground bar on the left side which is linked to the nueteral bar via a ground screw and copper link


What connects the two bars? The steel of the enclosure via the ground screw, or a copper / aluminum strap? 


MDShunk said:


> If you have the bond screw in that strap, either bar can be for either thing.


If it is a strap between the two, that is a grounded conductor, and ok.

If they are connected together by the MBJ and enclosure, I don't think it is compliant.


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## JohnJ0906 (Jan 22, 2007)

volty said:


> I
> 
> If they are connected together by the MBJ and enclosure, I don't think it is compliant.


Not under the '08 - 200.2(B)


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## Shockdoc (Mar 4, 2010)

I have installed the Murray panels rarely when supply and cost were an issue,I am not a fan of them. I however did keep the grounds and neutrals seperate with those bars just for the sake of later changes(transfer switch installation) . I have just noticed many guys in an effort to keep wires neat, having all that enter the box on that side tied to that bar. One even forgot to tie in the bond strap, I did him a favor when I found it. Personally Square D QO is the way to go, but the cheap consumer gets the cheap apperatus. thanks for the input.


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## MDShunk (Jan 7, 2007)

Shockdoc said:


> Personally Square D QO is the way to go, but the cheap consumer gets the cheap apperatus. thanks for the input.


Yes, that's just business. I've often said, "there's an installation method for every budget". Some guys just can't bring themselves to do something they're not particularly proud of. The one's that can get over that malfunction get more work.


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## Shockdoc (Mar 4, 2010)

volty said:


> I might not be picturing this properly.
> 
> What connects the two bars? The steel of the enclosure via the ground screw, or a copper / aluminum strap?
> 
> ...


It is a ground bar linked to an aluminum strap that ends an inch from the main neutral bar where an optional green screw and copper strap is field attached to the main bar. I have found a good deal on GE panels for the lower end jobs to my liking(prefer the copper bus bar over Homeline) . 9 out of 10 Supply houses in this region sell only Murray. It's a NY profit thing.


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## NolaTigaBait (Oct 19, 2008)

JohnJ0906 said:


> Not under the '08 - 200.2(B)


I thought that I read that...So , according to this you have to terminate the neutral to the neutral bar.


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## JohnJ0906 (Jan 22, 2007)

Shockdoc said:


> panel with the ground bar on the left side which is linked to the nueteral bar via a ground screw and copper link,





NolaTigaBait said:


> I thought that I read that...So , according to this you have to terminate the neutral to the neutral bar.


I would think that if there is a conductor of some sort (i.e., a copper link, strap, wire, etc) it would be legal to terminate the neutral conductor on that bar. If the connection depends on the panel enclosure only, then IMO that is not allowed.


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## NolaTigaBait (Oct 19, 2008)

So, you are saying if the main bonding jumper is a strap it is ok...and if it is a screw then it is illegal?


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## Shockdoc (Mar 4, 2010)

JohnJ0906 said:


> I would think that if there is a conductor of some sort (i.e., a copper link, strap, wire, etc) it would be legal to terminate the neutral conductor on that bar. If the connection depends on the panel enclosure only, then IMO that is not allowed.


I tend to agree, on few occasions I have come across panels with no neutral spaces available where I have field installed a ground bar and linked it to the main neutral bar with a piece of #8 white.


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## JohnJ0906 (Jan 22, 2007)

Shockdoc said:


> I tend to agree, on few occasions I have come across panels with no neutral spaces available where I have field installed a ground bar and linked it to the main neutral bar with a piece of #8 white.


Personally, I install the ground bar, and relocate EGCs to it to free up space on the neutral bar for neutrals. Just my preference.


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## volty (Jan 14, 2009)

JohnJ0906 said:


> I would think that if there is a conductor of some sort (i.e., a copper link, strap, wire, etc) it would be legal to terminate the neutral conductor on that bar. If the connection depends on the panel enclosure only, then IMO that is not allowed.


I think that it can be legal only if not dependant on the Main Bonding Jumper, which by definition, is to connect the grounded circuit conductor and the grounding circuit conductor.

Not to connect the grounded conductor to some more grounded condutors. If the connection is completed by a screw required to have a green finish 250.28(B), which is a conductor, it shall not be used for grounded circuit conductors 250.119.


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## Shockdoc (Mar 4, 2010)

volty said:


> I think that it can be legal only if not dependant on the Main Bonding Jumper, which by definition, is to connect the grounded circuit conductor and the grounding circuit conductor.
> 
> Not to connect the grounded conductor to some more grounded condutors. If the connection is completed by a screw required to have a green finish 250.28(B), which is a conductor, it shall not be used for grounded circuit conductors 250.119.


Agree, If you ever came across the Murray supply house brochure, it shows the grounded conductors wired to this ground bar. The green screw is grounding and the strap is a ground bond for the panel enclosure. Just wait until i retire and become an inspector...


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