# service bonding 2011 NEC



## BSSTG (Jul 25, 2011)

Greetings all,

Well I'm confused with 250.92 (B).

My question is this. Are grounding bushings or grounding locknuts required on service conduits under all circumstances in lieu of standard locknuts now? Or are the gounding bushings and locknuts only required around concentric knockouts, reducing washers and so forth? It looks to me as if standard locknuts are not allowed for bonding of service equipment under any circumstance but I'm not sure if I'm reading this right

thanks

BS


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## Bryan Holland (Jul 25, 2011)

Here's how I understand it.

All the stuff in section 250.92(A)(1)&(2) are required to be bonded together.  The method for bonding these items together can be any of the (4) methods indicated in section 250.92(B).  Standard locknuts or bushings used by themselves can not be used to satisfy these requirements.  In addition, bonding jumpers are required where the potential for an impaired connection is present due to inadequate connection beetwen an enclosure and a raceay fitting.

The moral of the story is this.  When in doubt, bond.


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## raider1 (Jul 26, 2011)

BSSTG said:
			
		

> Greetings all,Well I'm confused with 250.92 (B).
> 
> My question is this. Are grounding bushings or grounding locknuts required on service conduits under all circumstances in lieu of standard locknuts now? Or are the gounding bushings and locknuts only required around concentric knockouts, reducing washers and so forth? It looks to me as if standard locknuts are not allowed for bonding of service equipment under any circumstance but I'm not sure if I'm reading this right
> 
> ...


This change was just a re-wording of the requirements already contained in 250.92.

Standard locknut can't be used for bonding on the line side of the service and bonding bushings or locknuts are required to bond metallic raceways on the line side of the service even if concentric, eccentric or reducing washers are encountered.

Chris


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## RJJ (Aug 2, 2011)

Chris: By any chance do you have a photo of a proper install? This is a great question and I agree with Bryan on when in doubt!


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## TimNY (Aug 2, 2011)

Also, if we could have the section.. for those of use who don't have the 2011 NEC yet    thanks!


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## raider1 (Aug 2, 2011)

TimNY said:
			
		

> Also, if we could have the section.. for those of use who don't have the 2011 NEC yet    thanks!


Check out 250.92(B).

Chris


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## Francis Vineyard (Aug 2, 2011)

From a good source;Wish I could download a better picture though

View attachment 468


View attachment 468


/monthly_2011_08/a250.92B.jpg.53e86fc16778b2340cbe4ae5934de007.jpg


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## RJJ (Aug 2, 2011)

Francis: Good enough! This is a section often missed. Sometimes a picture goes along ways to allowing ones understanding od an issue. It also can stimilate more discussion on a subject that needs clear understanding.


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## chris kennedy (Aug 2, 2011)

TimNY said:
			
		

> Also, if we could have the section.. for those of use who don't have the 2011 NEC yet    thanks!


This is how it reads.



> 250.92 Services.(B) Method of Bonding at the Service. Bonding jumpers
> 
> meeting the requirements of this article shall be used
> 
> ...


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## jar546 (Sep 12, 2019)

So here is the question.  If the service disconnect is a regular panelboard and the metal raceway entering the service panel comes through a concentric knockout, needs to be bonded with a bond bushing or bonding locknut, does that mean that all branch circuits and feeders that leave that same service panelboard must have the same bond bushings or bonding locknut if they are connected to a concentric KO with metal raceway?
Food for thought.....


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## Rick18071 (Sep 17, 2019)

2014 NEC Handbook says just the line side.


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## jar546 (Sep 17, 2019)

Rick18071 said:


> 2014 NEC Handbook says just the line side.



Is there anyone out there that requires this at service panels that have EMT or other metallic conduit leaving on branch circuits and feeders?

I do not for the record.


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