ECN Forum Forums Code Related Discussion NEC & other Code issues EGC attachment

Paul,
The hole(s) provided by the panel manufacturer for the connection of the main bonding jumper or the connection of the equipment bonding bus are not the same as a field tapped hole. The hole is punched first, providing a greater thickness to be tapped and better contact. That being said, I don't see how that is not a corrosion problem if removing the paint under a lug is a corrosion problem. Also if the interior of the panel is subject to corrosion, I think that there are much bigger problems than the corrosion of the can.
I don't see this any different than field cut threads on conduit where the factory applied corrosion protection has been removed by the act of threading the conduit. The code provides a provision for this and the same method could be used in the panel if there is a potential corrosion problem.
One more point on this, the orginal question is talking about a "large" conductor that won't fit on the provided neutral bar. To me that would require a screw larger than 10-32 and if the screw is larger the screw pitch is larger and the tapped threads in the can will provide very little contact.
Don

early, what do you mean by this?


You do not get to pick and choose the method of bonding connection, as long as it is not a sheet metal screw it is acceptable to the NEC.




[This message has been edited by iwire (edited 11-19-2005).]

As a legally authorized AHJ, I do get to approve the connection (90.4 & 90.7 & the definition of AHJ in 100).
If I feel that a grounding or bonding connection choice is not sufficient to provide a low impedance to ground, then I can, and do, refuse to allow it (250.4(a)(3)(4) & (5) and the definition of bonded in 100).
I can and do sometimes reverse my decisions upon the submission of additional information or test results. My decisions can also be appealed to a higher authority (90.6 and local regulations).
I do not hold a grudge, the aim is a safer installation (90.1(A)), and I choose to err on the side of caution.

gserve

"I have a situation where a EGC will not fit on the neutral bar in the service equipment. I have tried to find a listed and same manufacturer add-on grounding lug kit to no avail.Except for the article 110 listing requirement issue is there anything wrong with installing a bolt-on lug of proper size and bolting it to the side of the panel with a nut and bolt? Code references please."

You did not mention specifics: manufacturer, wire size, panel...

I find it hard to believe that such a grounding lug is not made. Typically you have to look around in the catalog to find it. Give us more information and our crowd might know what you need off hand.

I know that all of the major brands have kits that cover the whole range of possibilities.

early are you really an AHJ or are you an inspector?

In my area they are not the same thing.

We will have to agree to disagree as I do not believe either 90.4 or 90.7 allows you to refuse NEC allowed methods.

Corosion Resistive coating is required by code. Code does not require it at tapped holes for grounding unless I am missing something. I think not because you did not reference a code article on the matter. Only an opinion. Might I suggest you contack someone like Sq D or Hoffman who manufacture enclosures and ask them what UL approves as far as grounding an bonding. As as you will note 300.6 addressesCorrosion Protection both inside and out. Another good reference is Soars.

Resqcapt19

Actually the hole in the back of the panel is rounded in order to allow the panel to sit flat on the wall after the screw in inserted. There is really no more steel provided at that point.

e57

I agree rusty surface is as bad as a enamel painted surface. The problem with what you are showing with the can is that the code does not require it as it does when threading righd conduit. If it was required the code would say to use it. If the code does not say it then the inspector has to accept the fact that means and methods are the contractors. After all it is his moiney you are spending.

Paul what exactly is an "NEC Specialist"?



Yes sometimes it is rounded for the reason you stated. Usually that is not the reason as the panels mounting spots will be raised so that there will be air space behind it.

If you take the time to look carefully you will see the displaced metal from the hole punching process makes the spot where the threads are a bit thicker.

Bob



[This message has been edited by iwire (edited 11-20-2005).]

iwire,

I come from almost the same place you do. One state under. OK, technically, only the BO can make the call, but if the BO delegates that responsibility to an assistant, then that assistant then has AHJ power. I am a licensed BO, electrical contractor and electrical inspector in my state.

I do not refuse NEC allowed methods, but I do not approve methods that I believe are inferior either. What section of the NEC allows your method? I have cited several that require a low impedance grounding connection. Where is your method cited as an approved connection method?

By the way, we cannot chose to violate any sections of the code, in order to "trump" another. All sections of the code must be met.

Going back to the origional post, the guy wanted code references to allow his bolted on lug. There are none I am aware of. I do believe his search for a listed ground bar kit was ended prematurely.

gserve, what manufacturer makes your panel? How about a universal ground bar kit? Are any of those UL listed?