Adding a ground lug to a loadcenter

J

JohnHess

Member
Location
North East US
Occupation
Electrical Contractor
I have a question about whether this is compliant or not. An inspector failed me for installing a typical “chair lug” in a residential electrical panel. I added this lug because I had to land an EGC and the neutral bar inside of this main panel was absolutely full. It was also behind a birds nest of wires so I didn’t want to try to make room by removing EGC’s and splicing them.

I attached a picture below, this is not the installation that was failed, but it illustrates the same exact thing that I’ve done many times in different places.

I drilled a hole and tapped it to 10/32 threads using a drill/tap combo.
I removed the paint from the area.
I used a random brand UL listed lug and held it to the panel with a random brand UL listed green ground screw.

The inspector failed it because he said I have to use the ground bar that is listed on the panel’s label.

Back when I did commercial work I have used countless random chair lugs in transformers and enclosures and panels, etc.

What say you?

IMG_4479.jpeg
 
As long as the paint is removed and the screw engages the proper number of threads an EGC can connect directly to a metal enclosure. For a panel enclosure once there is a wire type EGC a ground bar is required. Look at 408.40.
 
infinity said:
As long as the paint is removed and the screw engages the proper number of threads an EGC can connect directly to a metal enclosure. For a panel enclosure once there is a wire type EGC a ground bar is required. Look at 408.40.
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I’m talking about what we would refer to as a main panel in the house which serves as the service disconnect and the neutral bar is bonded to the metal enclosure. Then the neutral bar is used to land both neutrals and EGC’s.
 
JohnHess said:
I’m talking about what we would refer to as a main panel in the house which serves as the service disconnect and the neutral bar is bonded to the metal enclosure. Then the neutral bar is used to land both neutrals and EGC’s.
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Is it a panelboard under Article 408? If so then 408.40 applies.
 
infinity said:
Is it a panelboard under Article 408? If so then 408.40 applies.
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I’m not really sure what you’re saying. I’m talking about pretty much 80% of the panels that are in houses that I go into. The bonded neutral bar is used for both neutrals and EGC’s. But it’s often completely full. I’m not installing the panel, that was done decades ago, I’m just adding a circuit to it.

The inspector failed me because I installed a ground lug to land the EGC of the circuit that I added instead of installing the ground bar that the label on the panel says to use as an accessory. He cited 110.3B.
 
JohnHess said:
The inspector failed me because I installed a ground lug to land the EGC of the circuit that I added instead of installing the ground bar that the label on the panel says to use as an accessory.
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An EGC in a panel enclosure requires a bus bar for its connection. I've provided the code section.
 
infinity said:
An EGC in a panel enclosure requires a bus bar for its connection. I've provided the code section.
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Ok, I misunderstood. I thought in your original post you meant that I could do what I proposed and then I misunderstood what you meant in the second sentence.

So apparently what I’ve been doing is not code compliant, but not for the reason that this inspector failed it.
 
JohnHess said:
Ok, I misunderstood. I thought in your original post you meant that I could do what I proposed and then I misunderstood what you meant in the second sentence.

So apparently what I’ve been doing is not code compliant, but not for the reason that this inspector failed it.
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In your OP you mentioned transformers, enclosures and panels. For transformers, metal boxes, other enclosures you can do the lug method, for a panel you would need to provide an EGC bus. I think that's what I was getting at in post #2.
 
I hate these "listing violations". Heres what i am always tempted to say:

"Oh really, you have so much confidence in the listing people huh? The ones who wee complicit in the AFCI debacle? the ones that list raintight emt fittings with a rubber washer and find that good and acceptable? The ones that list junk fittings all the time? The ones that are ok with sharp edges on the critical corners on PVC LBs? These people?"

I would probably actually say:

"I do not see any instructions listing acceptable ground bars or lugs and that only those can be used. I do not see that I have gone against anything stated in the instructions."
 
electrofelon said:
"I do not see any instructions listing acceptable ground bars or lugs and that only those can be used. I do not see that I have gone against anything stated in the instructions."
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The issue is not the listing, it's the code requirement to install an ground bar in any panel that has a wire type EGC. Even a single wire type EGC in a panel would kick in the requirement to have an ground bar so you couldn't install a terminal as shown in the photo and be code compliant. If the panel were wired with metal raceways as the EGC or cables (AC or MC-ap) that did not have a wire type EGC then the ground bar is not required.
 
infinity said:
The issue is not the listing, it's the code requirement to install an ground bar in any panel that has a wire type EGC. Even a single wire type EGC in a panel would kick in the requirement to have an ground bar so you couldn't install a terminal as shown in the photo and be code compliant. If the panel were wired with metal raceways as the EGC or cables (AC or MC-ap) that did not have a wire type EGC then the ground bar is not required.
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I agree. I was going on a general rant, and the inspector seemed to be citing "listing violations" and not the 408 article.
 
infinity said:
As long as the paint is removed and the screw engages the proper number of threads an EGC can connect directly to a metal enclosure. For a panel enclosure once there is a wire type EGC a ground bar is required. Look at 408.40.
Click to expand...

infinity said:
As long as the paint is removed and the screw engages the proper number of threads an EGC can connect directly to a metal enclosure. For a panel enclosure once there is a wire type EGC a ground bar is required. Look at 408.40.
Click to expand...
If the metal thickness is at least .0625 it should be sufficient to ensure 2 threads with a 10/32 screw.

Must holes that are punched for the ground bar connection are formed in a way that provides more threads than the required 2.
infinity said:
As long as the paint is removed and the screw engages the proper number of threads an EGC can connect directly to a metal enclosure. For a panel enclosure once there is a wire type EGC a ground bar is required. Look at 408.40.
Click to expand...
 
curt swartz said:
Personally I would be OK with the lug if a 1/4-20 bolt was used instead of a machine screw threaded into the thin metal.
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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.
 
wwhitney said:
408.40 doesn't actually require EGCs to land on the ground bar. So the installation in the picture doesn't change whether or not the panel complies with 408.40.

Cheers, Wayne
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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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