250.92(b) 1-4

[metalicat30]

I recently failed an inspection where the inspector cited 250.92(b). I have 6 4 inch emt conduit runs line side to a line side gutter all holes for connectors are punched to size no concentrics. I did not install grounding bushings. This is what i failed for.My connectors are set screw. I installed grounding wedges to satisfy the authority.He returned for reinspection and i asked him about 250.92(b)-3 which says the following.Threadless couplings and connectors where made up tight for metal raceways and metal clad cables.I asked him if this could pertain to set-screw connectors to which his reply was I DONT KNOW!!! Any and all comments are welcome thanks in advance

 

[infinity]

Re: 250.92(b) 1-4

In KO's that are punched to the proper size the EMT connectors would satisfy the bonding requirement and no additional bonding would be required unless this were serving service entrance conductors.

 

[benaround]

Re: 250.92(b) 1-4

metalicat30,

255.92(B) the last sentence says it all.

Standard locknuts or bushing shall not be the sole means for the bonding requirements of this section.

frank

 

[metalicat30]

Re: 250.92(b) 1-4

These are service entrance conductors.

 

[metalicat30]

Re: 250.92(b) 1-4

benaround explain note 3 then

 

[benaround]

Re: 250.92(b) 1-4

Hold on ,I'll be right back

frank

 

[infinity]

Re: 250.92(b) 1-4

Note 3 says that you can't use a standard locknut, so a bonding locknut would satisfy this section.

 

[benaround]

Re: 250.92(b) 1-4

metalicat30,

The 2005 Handbook (not a legal code) is refering the threadless type conn. to be ridge or IMC,

I can see your point of view,the way it is worded is up to the AHJ to interprut.

Just wondering,the wireway,was it bonded at the first inspection?

frank

 

[metalicat30]

Re: 250.92(b) 1-4

Yes sir it sure was thanks for your input.

 

[mc5w]

Re: 250.92(b) 1-4

The setscrew part of an EMT box connector is listed for service conduit grounding, but the locknut is not partially because the connector shoulder could be resting on paint.

The best way is to install grounding bushings. If these conduits are running from say a current transformer cabinet then equipment grounding conductors inside of the conduits for bonding the CT cabinet to the service switch are an excellent idea.

If these conduits are downstream of a service switch then you only need to do special bonding for over 250 volts to ground, explosionproof areas, and hospitals.