Bonding service nipples

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Beniah Naylor

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Location
Kansas
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Building Inspector
2017 NEC 250.92 (B) (Services) says that "bonding jumpers shall be used around impaired connections...oversized, concentric, or eccentric knock-outs. Standard locknuts or bushings shall not be the only means of bonding required by this section but shall be permitted to be installed to make mechanical connection of the raceway(s)"

So, when you have a metallic nipple that goes between the meter box and the box that houses the first means of disconnect, and there are no knock-outs left, the hole is not oversized, and the nipple is fastened with standard locknuts only, would it be considered to be bonded since there are no knock-outs or reducing washers?

Or is it not considered to be bonded because you used standard locknuts as your connection to the box? There is a period between the sentence talking about impaired connections, and the sentence talking about standard locknuts as a means of bonding, and a sentence is a group of words that expresses a complete thought.

The AHJ I work for has only been requiring bonding jumpers around impaired connections, but we have been discussing it internally and we are wondering if a strict reading of the code means me need to always have a listed bonding connection on service nipples, even when there are no knock-outs left and the hole is not oversized.

Any insight you guys have will be appreciated.
 
I have always read it as service equipment needs bonding no matter if there are concentric knockout, etc.. Usually we use bonding bushings
 
The nipple between the meter and service disconnect cannot be bonded solely with standard locknuts. The type of KO's is irrelevant regarding this requirement. The enhanced bonding method is required on one side of the nipple only.
 
infinity said:
The enhanced bonding method is required on one side of the nipple only.
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The very first time I bonded a service nipple, I was just handed parts and told to do it. Not knowing better, I put bonding bushings on both ends and ran a bare #4 through the nipple. Fortunately, I only terminated one end of it.
 
LarryFine said:
The very first time I bonded a service nipple, I was just handed parts and told to do it. Not knowing better, I put bonding bushings on both ends and ran a bare #4 through the nipple. Fortunately, I only terminated one end of it.
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I've seen that done quite a bit and probably did it a few times myself early in my career. All that does is put a smaller bonding conductor in parallel with the neutral which is a technical violation of 250.6(B).
 
infinity said:
I've seen that done quite a bit and probably did it a few times myself early in my career. All that does is put a smaller bonding conductor in parallel with the neutral which is a technical violation of 250.6(B).
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As I said, I only landed one end, but, yes, a #4 cu jumper can certainly handle half of a 200a service's neutral current.

But, again yes, it's definitely non-compliant. What I did was a waste of time and material, though. 🙄
 
ARE CHASE NIPPLES AND THREADED COUPLINGS SUITABLE FOR BONDING BETWEEN SERVICE ENCLOSURES

I SAY 250.92A CODE REQUIRES ALL SERVICE CONDUITS BE BONDED
 
INSPECTOR MARK said:
ARE CHASE NIPPLES AND THREADED COUPLINGS SUITABLE FOR BONDING BETWEEN SERVICE ENCLOSURES

I SAY 250.92A CODE REQUIRES ALL SERVICE CONDUITS BE BONDED
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Are you referring to a chase nipple threaded into a coupling?

Welcome to the Forum. Please turn the caps lock off. :)
 
Interesting question. My first thought was no, but re looking at 250.92 I'm going with maybe. I guess that would be a "connections utilizing threaded couplings". I am assuming that is intended for raceway to raceway connections, but they do not say that it can't be for raceway to enclosure connections. I'm being a real lawyer on this one 😉
 
Based on the straight versus tapered thread debate (although it's done every day) IMO a chase nipple is not permitted to be screwed into a coupling.
 
electrofelon said:
Interesting question. My first thought was no, but re looking at 250.92 I'm going with maybe. I guess that would be a "connections utilizing threaded couplings". I am assuming that is intended for raceway to raceway connections, but they do not say that it can't be for raceway to enclosure connections. I'm being a real lawyer on this one 😉
Click to expand...
ENCLOSURE TO ENCLOSURE CONNECTION
CONDUCTOIRS WITHIN ARE SERVICE CONDUCTORS
UL LISTING FOR MALE THREADED CONDUIT FITTINGS IS TESTED WITH LOCKNUTS AND IS LISTED FOR GROUNDING
NO LOCKNUTS USED HERE AND NO PAINT REMOVED
 
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