Grounding Compliance and 250.146

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Stubbie

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250.146 (A) addresses surface mounted boxes. It says that this provision shall not apply to cover mounted receptacles unless the box and cover combination are listed as providing satisfactory ground continuity between box and receptacle.
What constitutes a listed combination for grounding purposes?
We recently finished installing 33 overhead cord and plug fans with an EMT raceway method for egc. We used raco metal 4x4 boxes and raised metal covers for the receptacles. We installed the receptacles in compliance with 406.4(C).
We did not run the jumper from the receptacle grd screw to the box. Are we in violation of 250.146(a)?

Example of cover (ours were simplex)
038921706435_3.jpg
 
I agree with Don, but will add that it's hard to believe. The two 8-32 screws that hold on the raised adapter cover makes it suitable for grounding, but the same two screws together with the two screws holding the device to the cover doesn't.
 
Yes, you are in violation as stated.

NEC 2005 Handbook commentary:

The main rule of 250.146 requires an equipment bonding jumper to be installed between the device box and the receptacle grounding terminal. However, 250.146(A) permits the equipment bonding jumper to be omitted where the metal yoke of the device is in direct metal-to-metal contact with the metal device box and at least one of the fiber retention washers for the receptacle mounting screws is removed, as illustrated in Exhibit 250.52.

Cover-mounted wiring devices, such as on 4-in. square covers, are not considered grounded. Section 250.146(A) does not apply to cover-mounted receptacles, such as the one illustrated in Exhibit 250.53. Box-cover and device combinations listed as providing grounding continuity are permitted.

I agree with Don, after a search I could not find any listed box cover/device combinations.

Why the panel on this code chose to suggest this "permission"?

I don't know. Maybe some R&D is/was being done that they knew about so they left the door open.
 
Gmack you can post in your own words.

The handbook is a good tool but in the end is just someones opinion and carries no more weight than your opinion or mine.8)
 
Thank you Iwire, Im sort of still new here, and I believe I post a good share of my own word. To much sometimes :)

I post the NEC for others sake. So they can decide for themselves.

With some exceptions, "some", very few I will add, I believe the "word of the Handbook commentary text and "pictures" provide an immense value of combined
Code: 
 compliance/knowledge provided by the NEC itself.

Or it wouldnt bear the name of the NEC and all who approved it for publication.

In this case the OP asked if he were in a violation. I thought it would be good for him/her to study.

After all that said, I click on NEC to get here, so I try to focus on that.

Except when it comes to say, VOLTAGE!!!

It could be a case of Terrets [spelling]. Sorry. It just BLURTED OUT. :shock:
 
gmack I agree that the handbook is good but this is always in my mind when I use the NECH.

From the front of the Handbook.
The commentary and supplementary materials in this handbook are not a part of the Code and do not constitute Formal Interpretations of the NFPA (which can be obtained only through requests processed by the responsible technical committees in accordance with the published procedures of the NFPA). The commentary and supplementary materials, therefore, solely reflect the personal opinions of the editor or other contributors and do not necessarily represent the official position of the NFPA or its technical committees.
Click to expand...

It's likely they match but there are oddities.
 
Iwire, thats why it takes an "electrician" :)

Iwire, "we" are the end trade/installer of all this "stuff".

We have the distiction of the "cian" equal to mathemati"cian" Physi"cian".

Dont ever forget that.
 
Well, I was an electrician before you fired me. Now, I'm back to being a knuckle-dragging housemonkey. :lol:

I agree with Trevor, it does seem odd that one is permitted over the other. I didn't realize that receptacles were permitted to be bonded this way at all! :shock:
 
I am going to take a WAG (PM me if you don't know WAG)

The difference between a plaster ring and a raised cover is this.

The raised cover can be removed (or simple fall off) without removing the outlet.

A plaster ring when used as intended has its mounting screws hidden away.

It is my WAG that they do not want an ungrounded raised cover and or receptacle.
 
Thanks to all who replied. I cant argue that it looks pretty straight forward that we are not compliant. Looks like I will be busy making some grounding jumpers......maybe. I couldnt find any listing for a raised cover and box that was compliant either.
I wonder though why this doesnt have just as good a grounding connection as the yoke to the box. The metal to metal contact seems to be there in my eyes.
For what it is worth the inspectors are having no issue with the ground jumper not installed from the box to the receptacle. These 33 fans were the last of some 75 that were installed in the same manner.
Not a problem though....easy to fix. I wasnt withholding that. I just forgot to get into my thoughts in my first post. I'm not sure they will even let me go back and ground the receptacles.
 
georgestolz said:
Well, I was an electrician before you fired me. Now, I'm back to being a knuckle-dragging housemonkey. :lol:
Click to expand...

Don't worry George, you might be able to become a real electrician someday. :lol:
 
Stubbie said:
I wonder though why this doesnt have just as good a grounding connection as the yoke to the box. The metal to metal contact seems to be there in my eyes.
Click to expand...

Your right..it does...until the cover falls off ...pretty much in line with iwire's WAG.
 
Grounding jumpers can be loose if not installed in a workman manner.

George, I merely sent you home for the day. Instead you went 4 blocks down the road and drank beer with that little green apprentice of mine :lol:
 
I believe the reason this cover is not listed, is the manufacturer's see no need to pay to have it investigated for such use and consequently have to pay the fee. People will still use the cover regardless. When a standard changes that will make it necessary to have it become listed, I am willing to bet it would pass that test.
 
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