Non-Metallic box for light fixture crossbar needs grounding?

juant1971

Member
Location
Orlando Florida
Occupation
Temporary Power Distribution
Can anyone guide me to the code book article on grounding light fixtures. I have some vanity lights and ceiling fixtures coming from non-metallic boxes which aren't grounded to the metal crossbar. I am just curious if this is new practice to by pass the grounding screw on the crossbar. Or should I go into these fixtures and correct my findings?

Thank You
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Can anyone guide me to the code book article on grounding light fixtures. I have some vanity lights and ceiling fixtures coming from non-metallic boxes which aren't grounded to the metal crossbar. I am just curious if this is new practice to by pass the grounding screw on the crossbar. Or should I go into these fixtures and correct my findings?

Thank You
why would the support bar need to be grounded.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
what code basis is there for this. it is not likely to become energized.

You think a light bracket is not likely to get energized? I have seen it more than a few times sometimes. It happens when installing the fixture and the wire gets pinched between the fixture and the bracket.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
The code won't allow a nail to pass thru a switch box unless it is at the back of the box so why would you think the bracket would not need to be grounded. I am not sure what section exactly covers this. I don't have time to look right now
 

juant1971

Member
Location
Orlando Florida
Occupation
Temporary Power Distribution
what code basis is there for this. it is not likely to become energized.
On what basis are you relying to mentioned that it is not likely to become energized? I would be interested in documentation from a creditable source that states such if you have any? Thanks
 

juant1971

Member
Location
Orlando Florida
Occupation
Temporary Power Distribution
The code won't allow a nail to pass thru a switch box unless it is at the back of the box so why would you think the bracket would not need to be grounded. I am not sure what section exactly covers this. I don't have time to look right now
No worries I will keep searching for it thanks Dennis
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
I think this covers it

250.4(A)

(2) Grounding of Electrical Equipment. Normally non–
current-carrying conductive materials enclosing electrical
conductors or equipment, or forming part of such equipment,
shall be connected to earth so as to limit the voltage to ground
on these materials.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
This is what petersonra was referring to. IMO, it is likely to be energized. If a wire nut falls off and touches the bracket or a nick in the wire, then the bracket could be energized.

(4) Bonding of Electrically Conductive Materials and Other
Equipment. Normally non–current-carrying electrically
conductive materials that are likely to become energized shall
be connected together and to the electrical supply source in a
manner that establishes an effective ground-fault current path.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
So dennis, does that mean any structural element made of metal that has a plastic box attached to it needs to be bonded? what about metal studs? How about metal pipes?
 

480sparky

Senior Member
Location
Iowegia
110.3(B): If the instructions are part of the listing, and the instructions say the strap must be grounded, well........... like Ronnie Reagan used to say, "There ya go...."
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
So dennis, does that mean any structural element made of metal that has a plastic box attached to it needs to be bonded? what about metal studs? How about metal pipes?

Yes, there are plastic boxes that have metal screws but they are recessed in so that they are not easily contacted by a conductor. Those do not need to be grounded.

Boxes like this one you can clearly see the recess for the screw head. No grounding need here. If those screws were not recessed then you are violation without grounding the screws. Crazy huh....

 
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