box supports

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rayertz

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We have for example a 3/4" single hub FS box with a TW receptacle in it that feeds lighting fixtures by cord and plug. Conduit coming to the box is 3/4" EMT with a compression connector entering the box. The conduit is supported within 18" of the box with threaded rod 18" long the a Minnie.
Other examples are with a FSC box with the same type of arrangement only it has two conduits.

Do the boxes require support other than the conduit? I'm looking in 314 and not finding it.

Thanks for your advice.
 
Your box needs to be supported, it does not meet the requirements of 314.23(F).
If your conduits were RGS and not EMT it would be alright if you had more than one conduit entering the box.
 
For other than conduit bodies, you must have two or more conduits, generally RMC or IMC.

Also, the EMT compression connector is not listed for use in a hub entry.
 
tkb said:
It is a very common practice. I doubt the lack of the listing would make it a hazard.
Click to expand...
Not being listed is mostly because connectors are not tested for grounding continuity when threaded into a hub. But that is not why I mention it...

As best I can tell, [threaded] hubs are intended for threaded conduit only, which is why I bring it up. A connector introduces a point of box support failure. It is far less secure (because of the compression-conduit interface) than threading the associated conduit directly into the hub. Also, enclosures with hubs typically have beefier construction. I believe the intent is a hub entry is to be correlated with a conduit of sturdier construction in addition to direct connection. A point of contention is using threadless RMC, IMC fittings and I have not looked into the details of that scenario.

Now if one were to use say a bell box with non-hub threaded entries, I believe the less beefy construction would permit using connectors.
 
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