Fitting in lieu of a box?

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c_picard

Senior Member
Location
USA
If I'm using a wiring method listed for use outside of conduit (USE-2) and run it inside conduit (EMT) to get it where I need to, can I use an EMT connector with a insulated-throat bonding bushing at the termination of the conduit? Or is a box required at the end of the EMT?
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
It sounds like the conduit is used for physical protection and is a sleeve, not a raceway. As a sleeve, one just has to provide the bushing, or its equivalent, to protect the cable.
 

c_picard

Senior Member
Location
USA
300.15(C) was my first stop.

I have a very well-respected AHJ that views this as acceptable for the conduit installed between PV array sections, but not for the run back to the inverter. (I didn't post on the PV forum, because I'm looking to a broader audience for opinions:)

300.15(F) would address this scenario, even if one believes (C) does not apply. Here's where things get tricky to understand...it's common practice to terminate a run of EMT with a raintight connector and bonding bushing; the bushing provides abrasion protection, as well as a means to bond the conduit (most consider this obilgatory for 2008/2014 NEC cycles).

The AHJ in question needs documentation that the fittings used are indentified for the use per 300.15(F). I hold that the fittings are used precisely as listed, and therefore intended; to terminate the conduit run, provide abrasion protection and a place to bond the conduit.

Unfortunately, the definitions in UL 514B are a bit of a mess, because the definition of a fitting does not align with the NEC:

3.3 BUSHING: A FITTING provided to protect wires from abrasion and intended for use where
conductors enter or leave the raceway system

3.13 FITTING: A means for securing conduit, cable, or tubing to an enclosure, box, or raceway
system

This is one of the more challenging puzzles I've seen.
 

Smart $

Esteemed Member
Location
Ohio
300.15(C) was my first stop.
...
1) I realize many do this with sleeves or dead-ended conduit runs, but technically a connector is a fitting to terminate a conduit run (in this scenario) to an enclosure... so IMO, that's a 110.3(B) violation.

2) If one end connects to an enclosure, you have a conduit run... not a sleeve scenario at the other end (except under a few select NEC sections).

3) To terminate properly per NEC listing, labeling, or identification concepts typically requires a cable gland fitting. If this is no-jacket USE, you have to find one with a gland specifically for the multiplex size and configuration.

4) Keep in mind that even if you used a box to terminate the EMT run, you still need a listed, labeled, or identified cable connector to exit the box.
 
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