ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
dsk 13
Admin 5
Recent Posts
electircal ageing test on IPC
by SIAME. 08/15/17 02:43 AM
electrical aging test on IPC
by gfretwell. 08/15/17 12:27 AM
Bathroom electrical
by gfretwell. 08/14/17 02:05 AM
"Line level" audio on Cat 5?
by gfretwell. 08/08/17 10:39 PM
Fire alarm phone lines and color coding
by gfretwell. 08/08/17 10:26 PM
New in the Gallery:
Housebilding DIY wiring
Popular Topics(Views)
239,856 Are you busy
175,412 Re: Forum
167,703 Need opinion
Who's Online Now
0 registered members (), 45 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#206734 - 08/04/12 12:26 PM Bond bushings  
SJT  Offline
Member
Joined: Jul 2002
Posts: 241
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


2017 / 2014 NEC & Related Books and Study Guides

#206739 - 08/04/12 10:54 PM Re: Bond bushings [Re: SJT]  
Tesla  Offline
Member
Joined: Jun 2004
Posts: 1,273
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


Member Spotlight
TOOL_5150
TOOL_5150
Bay Area
Posts: 61
Joined: August 2007
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.015s Queries: 15 (0.003s) Memory: 0.7439 MB (Peak: 0.8628 MB) Zlib enabled. Server Time: 2017-08-16 15:10:09 UTC