ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

Topic Options
Rate This Topic
#206734 - 08/04/12 09:26 AM Bond bushings
SJT Offline
Member
Registered: 07/24/02
Posts: 241
Loc: PATCHOGUE, N.Y.
In regard to threaded grounding bushings (with grounding lug on it), where are these to be installed?
I was checking 250.97 and 300.4(G) in the code.
If possible, could you refer me to the code sections, where we must install such bushings, as compared to normal bushings?
Just trying to have code references, so we don't install ground bushings where they are not needed.
Thanks - Good day
SJT
Top
2017 / 2014 NEC & Related Books and Study Guides
#206739 - 08/04/12 07:54 PM Re: Bond bushings [Re: SJT]
Tesla Offline
Member
Registered: 06/16/04
Posts: 1273
Loc: Sacramento, CA
The SINGLE most common use for such grounding bushings is at the terminus of an EMT, GRC, IMC, Flex shielded run on a GEC -- wherever its headed.

Sometimes I've installed them as a grounding lug even with a naked bare GEC system bonding conductor.

Other than that, they've got little purpose.

They are never used to replace lazy-lugs/ lay-in lugs.

And they are typically UL listed for conductor size -- maxxed at 3/0 -- the largest GEC from the table.

That's one hint from the manufacturer/ UL as to their purpose -- they're choke eliminators -- and the inspector will be looking for them on all GEC bonding runs that are wrapped in steel pipe/ steel flex.

They are NOT required if the same run is wrapped in PVC.

As for GEC Systems, the NEC Handbook has sweet illustrations. Exhibit 250.32 [ BTW, the bushing is normally attached physically to the raceway -- but it doesn't absolutely have to -- see the diagram.

NEC 250.64.E

NEC 250.104

Happy to post the citations for the forum...

(2005 copy...)
_________________________
Tesla
Top

Member Spotlight
Member Since: 07/05/02
Posts: 8211
New in the Gallery:
SE cable question
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box


Who's Online
0 registered (), 50 Guests and 11 Spiders online.
Key: Admin, Global Mod, Mod
 
New in the Gallery:
SE cable question
 
Top Posters (30 Days)
Admin 79
HotLine1 51
Ruben Rocha 29
gfretwell 25
Trumpy 20
 
Newest Members
clee512, Jdscott2005, FAIZAN, Regitest2, sureshazhagai

ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals