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Discussion Starter · #1 · (Edited)
Lets say you have 2 ground bars in a standard residential panel. One bar is on the even side and another is odd side. Both are secured via machine screws to the panelboard. One bar has the ground ran with the feeders attached to it. Do you need to run a jumper to connect the ground bars together
 

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Discussion Starter · #5 ·
I take it neither one has a bonding screw? I don't think screwing them to the panel counts. Unless they used green screws. Ask your AHJ.
Nope, neither has a bonding screws. The meter serves as the means of disconnect as its an apartment building so all the meters are in an electric room. The panel has no main breaker
 

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you won't find it. however, inspectors have required me to use a jumper, and I have caved and done it.

short answer, if you have 2 machine threads (250.8 A 8 -2014, or machine screw + nut, no.
 

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Not sure. Panel was sent out with 2 ground bars and they were both used using the factory machine threads provided. I know that neutrals cant be dependent on the panel for continuity because of 200-2(B) but I cant recall a similar article for grounding.
What do the panel instructions & stickers say? If that doesn't help contact the manufacturer or just go ahead & bond them. You could ask the AHJ.
 

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Discussion Starter · #8 ·
you won't find it. however, inspectors have required me to use a jumper, and I have caved and done it.

short answer, if you have 2 machine threads (250.8 A 8 -2014, or machine screw + nut, no.
That's what has been bothering me. I have seen it done also but I cant find a code reference for it and if I don't need a jumper connecting the 2 bars than why should I connect them.
 

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just so it get's said, a panel is not building steel. I don't think inspectors have a right to ask unless there is an amendment to cite.
 

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Nope, neither has a bonding screws. The meter serves as the means of disconnect as its an apartment building so all the meters are in an electric room. The panel has no main breaker
So, it's basically a "mains" disconnect? I would think a "main bonding jumper" would be required. Is the neutral bus in the "sub-panel's" isolated?
 

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Discussion Starter · #11 ·
So, it's basically a "mains" disconnect? I would think a "main bonding jumper" would be required. Is the neutral bus in the "sub-panel's" isolated?
Yes neutrals are separated from grounds. 2 Neutral bars, one on each side of panel and on plastic so they don't touch any metal and they have a strap that goes across to connect them.....all done by the manufacturer
 

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Huh?

You're asking if you can mount 2 ground bars in a panel, and these ground bars are attached with the machine screws?

Yes you can,

Do you need green ground screws for them? No

I assume you already have a separate neutral bar, right?
 

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I have a friend in the trade who adds the jumper, and I don't think its a code requirement. Macmikes way of explaining it is maybe the best rationale I've heard, but I don't think you'll find it in the book specifically.
 

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Lets say you have 2 ground bars in a standard residential panel. One bar is on the even side and another is odd side. Both are secured via machine screws to the panelboard. One bar has the ground ran with the feeders attached to it. Do you need to run a jumper to connect the ground bars together
No,

Did it come from the manufacturer that way? NO
Did you install the ground bars? NO

I can guarantee the metal back box has more conducting surface area than a #6 AWG CU.

Common sense is leaving this trade in droves.
 

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Can't Remember
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I just use the greenlee drill tap for the screw size that comes with the bar if I'm locating it where there is no factory holes, which is most of the time. The only time I use the green screw is for small foot lugs because I have them and its convenient.
 

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The Accidental Welder
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No jumper.

I would be beating any inspector that tried requiring that over the head with a piece of 500. If I'm in a good mood at the time, it'd be Al. :biggrin:



Would that same inspector not allow the use of AC or MCap cable? How about using that rigid as an EGC? :rolleyes:
 

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I would be beating any inspector that tried requiring that over the head with a piece of 500. If I'm in a good mood at the time, it'd be Al. :biggrin:



Would that same inspector not allow the use of AC or MCap cable? How about using that rigid as an EGC? :rolleyes:
CORREC T -:vs_clap:

What do you do in a junction box EMT in EMT out with the EGC when have to splice, the same thing.
 

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I just use the greenlee drill tap for the screw size that comes with the bar if I'm locating it where there is no factory holes, which is most of the time. .
I use a #10 self tapper to drill and tap the hole, and then screw a #10 machine screw into the hole.
 

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Let me mention one thing:

If this panel was fed with EMT, with the EMT being used as the equipment grounding conductor, you would have no wire type EGC.

With that said, it is perfectly acceptable to use the machine screws to secure the ground bar(s) to the panel with nothing else required, no bonding jumpers, etc.

The green screw being mentioned in posts above is used as a main bonding jumper to tie the grounded conductor at the neutral bar to the equipment grounding conductors at the service disconnecting means.

If you are simply installing or working with ground bars in a panel, and not the neutral bar in a service panel, there is no green screw (main bonding jumper) requirement.
 
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