ECN Forum Forums Code Related Discussion NEC & other Code issues Bonding of receptacles

250.118 Says EMT & Rigid Ect are approved equipment grounding conductors, But we"re not talking about raceways here. As I stated before 250.146 Clearly States & shows (Pics & All in handbook page 254.)The direct metal contact referes to a Surface box & the outlet put directly to the box (example handy box) , Not via removeable cover. A Pig tail for that type of cover (removeable is required. I Know the handbook is not code But I;ll bet you a lotta Inspectors ect go a lot by it .George bring it up at the Dec. Meeting.
Yoopersup
Yoopersup

Oddly enough, 250.146(A) directly addresses this point, specifically saying you do NOT need the jumper for the covers with the "flat, non raised" corners. At least, that's what the text of the code says.

In the handbook, the illustration right next to the section (pg 254) says the exact opposite. It appears to me that there's a typo, the word 'not' having been omitted from the artwork.

Keep in mind that this same section would apply to 'cut in' or 'old work' boxes, which are 'surface mounted,' even though the bulk of the box is within the wall. That is, 'old work' boxes do not require the use of jumpers.

Likewise, bonding works in both directions. That is, if the box does not require a jumper, then there is no need for one - even if the ground wire is terminated directly to the device. That's how I see it.

You are still left with this

As for the new MC, time will tell.
I give it about a 50:50 chance that there will be a problem with a failed ground and there will be a big stink about it.
It will just depend on whether someone gets hurt and the family sues.

"Listing" is something that is simply unknowable from looking at a picture, or some artwork. One would have to see the packaging.

That also brings up the bugaboo regarding the 'combination.' What if you have a Raco box and a T&B cover? Though both are built to the same NEMA spec -unlike circuit breakers, which can be any shape or size- you're opening the door to another similar dispute.

I'd love to see UL weigh in on this. Do they have a separate listing standard for these covers? Do they consider mixing manufacturers an issue?

All of these efforts at nit-picking do nothing to detract from the pictures I posted, to illustrate both the 'flat, non raised' cover from the other version. I'd say we have to give that version the benefit of the doubt.

Which, of course, leads us to respond to the OP: "No, the code has not essentially required that all cover mounted receptacles have pigtails." Had the code panel wanted to say that, they would have done so.

The later assertion that 'this section was meant to apply to handy boxes' is also shown to be in error.

250.146A states Direct contact between the BOX & the Yoke or Device.250.146 B then states Contact devices or YOKES designed and Listed as self grounding ect ect.
Thoses sections are refering to Yoke & Device connections Not Box cover connections.
The 2002,2005,2008 Code handbooks all have the same info and pics! Guess there all wrong then???
Yoopersup

If you have a cover with a riveted receptacle you are good to go.

Beyond that we are asking "what is a thread locking means".

I can't speak for the other editions, Youpersup, but your presentation of what is in the 2008 handbook is in error - as is the artwork in the illustration. Earlier editions did not reference the 'flat, non-raised' parts of covers, as that is new to the 2008 code.

I say the handbook is in error, becuse the language accompanying the artwork is exactly opposite of the code section - which is printed right next to the artwork. They both can't be right.

As for thread locking, there's really nothing vague about that. I mean, "Machinery's handbook" and other shop references are replete with discussion of the various means. Since no specific method is called for by the code, I'd have to accept any method. Naturally, some of these methods cannot be identified without taking the thing apart - and such action might destroy the thread-locking mechanism.

All these semantics being tossed about, attempting to extend the code beyond what it says, remind me of the 'sheet metal screw' silliness of a few years back. I submit that if we're reduced to arguing what the meaning of 'is' is, then perhaps we have bad code, that the code has crossed over into design work - something the code explicitly states is outside its' scope.

Now, if someone has a different understanding as to what the code is referring to when it speaks of 'flat non-raised' parts of covers, I'd love to see a picture. As best I can tell, the code was written as it was so as to specifically allow the use of these covers without need for a jumper.

So, is it safe to say that none of these covers are currently listed for grounding?
Is this perhaps another one of those NEC catch 22’s, something like the AFCI outlet devices that don’t currently exist, but we can supposedly use?
BTW: I see that Siemens is finally releasing a 2-pole combo AFCI CB.

I would believe any cover that had the receptacle riveted to it as an assembly was OK, even a field riveted assembly. I would also go for a nut that had the locking mechanism, either the domed nut with the plastic sleeve in the end or one with a pressed dimple on the side. What I would be skeptical of would be a regular machine nut or one of those stamped, threaded things that comes sometimes with a cover. They are trying to be sure this receptacle is not going to come loose from years of plugging and unplugging. That was why they did away with allowing the single center screw to attach them in the first place.

I haven't looked but I would be surprised if someone is not selling a cover/receptacle assembly that is riveted.