Bushings

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nyhockey

nyhockey

Senior Member
Location
long island, ny
I was always under the impression that bushings were only needed when using #4 wire (300.4(F)) and larger. While making test questions I find that they are required in a host of other applications:
342.46 IMC
344.46 RMC
352.46 RNC
353.46 HDPE
354.46 NUCC
362.46 ENT

Does this mean always? What about 358 EMT, that falls under the #4 wire Art?

:-?:-?:-?:-?:-?:-?:-?:-?
 
"the devil is in the details"...... in all of the xxx.46 sections, it also states:
unless the box, fitting, or enclosure design provides equivalent protection.
does the rounded edge of a connector satisfy that requirement ?
 
I'm unsure of an "answer" and wish that was not the case.
There have been several threads here where the requirement for a bushing on a PVC male adapter with conditions larger than #4 has been discussed. My memory is that the "required" outweighed the "not required", but the opinion was not unanimous.
I feel you have the same situation with the ***.46 sections.
"equivalent to the bushing" is a judgment call. On terminations of IMC or GRS I like to see a bushing on all conduits due to the "edge" but I will admit I have not enforced that "call" on smaller conduits...suggested it as a good idea, but not rejected....
I have accepted most 'fitting" terminations (smaller than #4) as the don't seem to have the sharp edge.
Unfortunately all the above is just the opinion of 1 inspector.
 
The problem with an EMT connector or a PVC MA is the weight of the conductors being fed into the connector. Certainly some #10's will go in with little problem but 4-600 kcmil copper conductors would probably be a problem. Just the weight of the conductor rubbing against the bare connector during wire pulling could easily damage the insulation.
 
I can recall a few jobs where we ran 1/2" RMC and I used bushings.
Every time I bought them, the supply house had to wipe heavy dust off the box :)
 
augie47 said:
I can recall a few jobs where we ran 1/2" RMC and I used bushings.
Every time I bought them, the supply house had to wipe heavy dust off the box :)
Click to expand...
We used to have untold numbers of these strung on pieces of solid wire and hanging around the shop. They would get buried among the other stuff but show up when the trucks were cleaned every few years or so.
 
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