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Joined: Nov 2001
Posts: 75
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Please help settle a question here at work.
Is it an NEC requirement to connect a ground wire to metal doors/covers of junction boxes and cabinets? Without the ground wire, when the hinged doors are open there is no solid ground connection to the ground bar on the back panel.
Some here are saying it is necessary to run a ground wire only when pushbuttons & lights are mounted on the doors.
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Joined: Dec 2004
Posts: 1,064
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Wouldn't that be a "bonding" wire?
I am in the process of reading the 2005 Soares, and I would like to know if that would be considered grounded or bonded?
Either way, I don't think it could hurt to put the strap on the door as the hinges are not listed as bonding types.
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Joined: Aug 2001
Posts: 335
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Since there is no source of power in the door (no indicator lights etc) there is no way for the door to become energized except thru the "can" (and that is bonded).
I vote no ... and I have absolutely no NEC reference to support it.
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Joined: Nov 2001
Posts: 75
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Thanks for the info so far.
Just to follow up a little, I'm not sure if the proper terminology would be bonded or grounded, but IF a live wire came into contact with the door, shouldn't it be solidly grounded (bonded).
It is commonplace to run ground wires to all of the columns of a building and they don't have anything electrical mounted on them either.
Still looking for futher input.... Thanks.
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Joined: Mar 2001
Posts: 2,056
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I have done my share of "Hoffman" enclosures and other control cabinets, even hinged JBs in Hazardous Locations. Although Hoffman includes a tooth washer to bond the back panel and enclosure together, I've never seen accessories included to bond the door.
BTW,
I would say that any connection would be a "bonding" jumper and its purpose would be to "ground" the door by establishing a solid connection between the 2 components
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Joined: Dec 2004
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The reason I brought up "bonding vs grounding", is because I was thinking on how you would size that jumper.
Do you size it on the largest conductor feeding the cabinet, or the largest conductor feeding the door lights or buttons?
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Joined: Mar 2001
Posts: 2,056
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250.102(D) would require it be sized based on OCPD rating per Table 250.122.
But,
I still don't think you need one.
[This message has been edited by Redsy (edited 04-14-2005).]
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Tom
Shinnston, WV USA
Posts: 1,044
Joined: January 2001
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