ECN Forum Forums Code Related Discussion NEC & other Code issues Need opinion

Zapped,
You are talking about two different rules. If the main bonding jumper in the service equipment is a screw, that screw must have a green head. See 250.28(B). The purpose of this rule was to make it easier for the inspector to see if the main bonding jumper was installed. The other rule in 250.8 prohibits the use of a "sheet metal screw" to connect a grounding conductor to an enclosure. The only problem with this rule is no one knows what a "sheet metal screw" is.
Don

Not permitted! Absolutely not!

I never would allow the cable clamp threaded hole to be used for the termination of the EGC or EBJ!

Listed products identify that hole in metal boxes with "GR" or "GRND" and one regular reference is 110.3(B)!

Joe, the intent is to be sure that at lease two threads are fully engaged. In the case of standard boxes, it makes no difference which hole is used as long as it used for no other purpose (you will find nothing in the Code or the UL White Book that prohibits this practice). Additionally, the guys from the NFPA do not serve on the Code Making Panels, the serve the panels by acting as the recorders of the panel actions. Lastly, the screw from the clamp may be used if the clamp is removed.

Hogwash!!

Good argument!

Joe,
Both holes are threaded with the same 10-32 tap. How is one better for the purpose of connecting the EGC than the other????????/
Don

Don:

OK, I agree with your thoughts, but when was the last time you worked in an existing building trying to fish in and re-wire, or add additional circuits?

Say, the original electrician installed 4 inch square metal boxes, (1900 Boxes) and did not use all of the cable entries, removed the clamp(s) that were not used, and attached the EBJ or EGC to the screw you mention, often with no real head on it?

Now the new installer, who may be a DIY'er takes the cable into the opening where the cable is usually installed, and doesn't have a clamp like we might in our junk box?

I see that as the possible future hazard, that it could represent, because the installer will, and has installed the cable into the box without any clamps all.

I have seen this happen many times during my career, where the cables were not secured to a clamp because it was not in the box!

I am sure that some of the other "old work installers" here understand what I am talking about.

There were comments made by someone indicating that the IAEI One and Two Family includes the discussion that supports my issue and that clamps are not allowed.

It should be noted that both the present Author, and Previous Authors Simmons and Tedesco have been members of the CMP Panels involved.

Joe, I don't believe you are reaching as far as to invoke the "I used to be a panel member" argument. You know, as well as I do, that panel members have differing opinions and it is the panel as a whole that makes the decision, not one or two members.

When Phil Simmons makes a statement, I normally agree with him. The point is that I don't always agree with him, or you. That does not necessarily make either of us wrong unless the words prove us wrong.

I have asked you for the words that make me wrong and I get a response of "hogwash". I am glad you do not inspect anymore. You can only enforce what is now, not what might be in the future. You can only enforce what the Code requires, not what you think it should say.

To answer your other question, yes, I am still an inspector in areas that do not have an AHJ. I am listed in our Electric Service and Meter Manual for that reason.

Are you going to Salt Lake City? I will be meeting Ryan Jackson, Mike Holt, and a bunch of others there.

Joe,
When I do a "rope" job, which is very very rare, I always remove any unused internal clamps. I think that makes for a more "workmanlike" installation, so even if I don't use the clamp screw for the EGC termination, there is still no clamp left in the box for the next guy.
Don

Don, I've been known to use boxes with 1/2" K-Os and a romex connector(C-500). What is the next guy going to do with just a 1/2" K-O ? You can't make it idiot proof, maybe idiot resistant, but not idiot proof. This past winter we did a custom home with all steel boxes as per spec. When we went to trim out we discovered several boxes did not have the threaded ground screw hole. Just a dimple with GND stamped next to it. We drilled and tapped these boxes because the GC didn't think too much of our alternate plan of ripping the defective boxes out of the finished walls. My drilled and tapped holes weren't listed but they were made with the proper size drill bit and threaded with a tap and were identical to the other factory drilled/tapped holes in the box.