Adding a ground lug to a loadcenter

infinity said:
The ground bar is required so that you can connect any wire type EGC's to it, it is not only there just to look at. :rolleyes:
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It says that there needs to be one, but it doesn’t prohibit any other way of landing an EGC. Maybe it’s for making future installations easier if the installer wants to use the ground bar.

We have to install an intersystem bonding block on a service, but there’s nothing saying it has to be used. The utilities ground their systems in any way that they choose.
 
infinity said:
The ground bar is required so that you can connect any wire type EGC's to it, it is not only there just to look at. :rolleyes:
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The ground bar is required so that the installer has the option, but there's no sentence in 408.40 saying you have to use it. In contrast, the first sentence of the second paragraph of (2017) 408.40 says "Equipment grounding conductors shall not be connected to a terminal bar provided for grounded conductors or neutral conductors unless . . ." Obviously the first paragraph could have used a similar form of sentence to say "Equipment grounding conductors of the wire type shall be connected to the provided terminal bar." But it doesn't, so it's not required.

Case in point--you come to install a branch circuit in a panelboard, which will be the last branch circuit as the panel will now be full, and you find the ground bar full. And the ground bar is not labeled for multiple conductors per hole, and you don't want to splice two ground together with a wirenut. Are you saying you have to install an additional terminal bar to terminate your wire-type EGC, rather than just using a lug as shown in the OP? 408.40 doesn't say that.

For that matter, isn't such a lug equivalent to a terminal bar with just one hole?

Cheers, Wayne
 
JohnHess said:
It's threaded into the panel the same way as a ground bar would be. If anything, it's threaded better since a proper tap was used instead of letting the screw use brute force to make the threads like happens with typical resi panel ground bars.
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I think a thread forming screw probably makes a better tighter connection than tapping the hole. I know when i have used those the screw is much stiffer. Tapping the hole makes it loosy until it gets tightened down.

Thread forming screws can sometimes be shot after screwing them in to form the threads, or maybe the head gets buggered from the force to make the threads. Sometimes I toss them and use a second new one if the first got messed up.
 
JohnHess said:
It says that there needs to be one, but it doesn’t prohibit any other way of landing an EGC. Maybe it’s for making future installations easier if the installer wants to use the ground bar.
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Like the inspector in the OP Mike Holt disagrees with you. :)
Mike Holt: Where equipment grounding conductors of the wire type enter a panelboard metal cabinet, they must terminate to a grounding terminal bar within the panelboard metal cabinet frame [Sec. 408.40].
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www.ecmweb.com

NEC Requirements for Switchboards and Panelboards

Switchboards and panelboards are often called “the guts” of a premises wiring system.
www.ecmweb.com www.ecmweb.com
 
retirede said:
Playing the devil’s advocate, is there any NEC definition of “grounding terminal bar” that would not be met by the lug in question?
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I agree that the wording is poor but the intent is for any wire type EGC's to terminate on the ground bar.

I bet UL has a definition of grounding terminal bar.
 
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