Bonding Bushing Listing.

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c_picard

Senior Member
Location
USA
I learned something new today, 2 of the commonly available bonding bushings (RACO, Arlington) that are often used to bond EMT conduit where required are only listed for use with Rigid and IMC.

Can anyone suggest a bushing that is listed for use with an EMT connector?
 
Dennis Alwon

Dennis Alwon

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Chapel Hill, NC
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Retired Electrical Contractor
Garvin makes them that can be used on emt. http://www.garvinindustries.com/electrical-fittings/rigid-imc-fittings/grounding-bushings-split-collar


Grounding Bushings - Split Collar
Application:
These split body grounding bushings are used on conduits that require grounding wires to be installed. They may be used on EMT, rigid conduit and IMC conduits. Their versatile grounding lug positioning and two-screw "clamp-on" action ensures a super tight bond between the pipe, bushing and ground conductor.
Advantages::
Garvin Industries’ split grounding bushing design allows ground bushings to be clamped around existing conduits. Our new "SGB" series saves countless labor hours and ensures that power stays on while the grounding bushing is installed. Both styles may be used on EMT, rigid conduit and IMC conduits. Additionally, their versatile lay-in ground lug can be mounted in multiple spots on bushings for ease of ground wire installation. These bushings feature dual-rated aluminum grounding lugs that may be used with both copper and aluminum grounding conductors. Versatile ground lug positioning allows for easy field modifications.
Field Names::
Split collar ground bushing, split grounding bushing, split ground bushing, open ground bushing, adjustable grounding bushing, ground bushing, grounding bushing, removable grounding bushing, clamp on split grounding bushing, 2 piece grounding bushing, 2 piece ground bushing.
Click to expand...
 
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c_picard

Senior Member
Location
USA
Good question. I guess I shouldn't assume anything.

Had a wiring inspector call this out on a 3/4" EMT that contained the GEC, bonded at both ends using the most common bonding bushing I've seen.
 
augie47

augie47

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Tennessee
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State Electrical Inspector (Retired)
c_picard said:
I learned something new today, 2 of the commonly available bonding bushings (RACO, Arlington) that are often used to bond EMT conduit where required are only listed for use with Rigid and IMC.

Can anyone suggest a bushing that is listed for use with an EMT connector?
Click to expand...

Not doubting what you state, but may I ask how you determined that they were not listed for EMT. I have not yet located that fact in Arlington's catalog or cut sheets.
 
Dennis Alwon

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I repeat- I have never heard of it and here is what UL book states. I cannot see what difference it makes. Aren't the threads the same?

Grounding and Bonding Bushings ? Bonding bushings for use with
conduit fittings, tubing (EMT) fittings, threaded rigid metal and intermediate
metal conduit, or unthreaded rigid metal and intermediate metal conduit
are provided with means (usually one or more set screws) for reliably
bonding the bushing (and the conduit on which it is attached) to the metal
equipment enclosure or box. They provide the electrical continuity
required by the NEC at service equipment and for circuits rated over 250
V. Means for connecting a grounding or bonding conductor are not provided
and if there is need for such a conductor a grounding bushing
should be used.
Grounding bushings for use with conduit fittings, tubing (EMT) fittings,
threaded rigid metal and intermediate metal conduit, or unthreaded rigid
metal and intermediate metal conduit have provision for the connection of
a bonding or grounding wire or have means for mounting a wire connector
available from the manufacturer. Such a bushing may also have means
(usually one or more set screws) for reliably bonding the bushing to the
metal equipment enclosure or box in the same manner that this is accomplished
by a bonding bushing. Grounding bushings provide the electrical
continuity required by the NEC at service equipment and for circuits rated
over 250 V. They may be used with or without a bonding or grounding
conductor as determined by the bonding or grounding function that is
intended to be accomplished.
Insulating throat liners in grounding or bonding bushings are suitable
for temperatures of 150?C if they are black or brown in color. Unless otherwise
marked, insulating throat liners of any other color are suitable for
temperatures of 90?C.
Click to expand...
 
kwired

kwired

Electron manager
Location
NE Nebraska
The bonding bushing does not bond the EMT it bonds the EMT connector if that is where it is attached to. Doesn't matter how it is designed, if it attaches to the connector it is bonding the connector.

Am I missing something here? How is any bonding bushing going to bond any raceway if attached to a connector other than via the connector?
 
mark32

mark32

Senior Member
Location
Currently in NJ
That inspector is bonkers, never heard of such a thing. "Hey, this bonding bushing is only meant to be installed on RMC or IMC, not an EMT connector". What is the difference, they all use the same lock nut. Maybe this guy is friends with this guy I had at HD last month, asked me for the set screw type of bonding bushing, which we don't sell, but I showed him the ones we sell w/the lay in lug. "Oh no, I can't use those", "Why not" I asked. "Code" he simply stated. "What code would that be" I replied and that's when he said that he's an electrician with over 20 years of experience. "Yeah, well then you should know that this would be an alternative item to the one you're looking for". We went back and forth a bit more and soon he calmed down but he still didn't buy the lay in lug jobs, at least not when I was looking.
 
Last edited:
infinity

infinity

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Location
New Jersey
Occupation
Journeyman Electrician
Although RMC threads are tapered and EMT connector threads are straight it shouldn't matter. Doesn't a bonding bushing have a set screw to bite into the thread?
 
G

GoldDigger

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Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
jumper said:
Here is a link to the 2012.

http://www.google.com/url?sa=t&rct=...=Cnt2la8X7piofTR7OAoySw&bvm=bv.47883778,d.dmQ
Click to expand...


Not quite to the OP's point, but interesting, from p. 118 (italics mine):
All metal fittings for metal cable, conduit and tubing are considered suitable
for grounding for use in circuits over and under 250 V and where
installed in accordance with the NEC, except as noted for flexible metal conduit
fittings and liquid-tight flexible metal conduit fittings.
Click to expand...

So if the fitting is suitable for use with EMT, it is suitable for grounding EMT. Which puts us right back where we started.....

And on page 217:
Grounding and Bonding Bushings ? Bonding bushings for use with
conduit fittings, tubing (EMT) fittings, threaded rigid metal and intermediate
metal conduit, or unthreaded rigid metal and intermediate metal conduit
are provided with means (usually one or more set screws) for reliably
bonding the bushing (and the conduit on which it is attached) to the metal
equipment enclosure or box.
Click to expand...
 
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