Quick question conduit size

[Twoskinsoneman]

What's the ref for smallest size conduit for branch circuits?
thanks

 

[celtic]

Not sure I understand the question ..but start by checking 3xx.20

 

[Twoskinsoneman]

I may be crazy but I thought there was a NEC article that generally limited conduit sizes to 1/2" and larger...

 

[celtic]

I may be crazy but I thought there was a NEC article that generally limited conduit sizes to 1/2" and larger...

That would depend on the conduit type in particular...some go as low as 3/8" (356.20)

 

[infinity]

Since he said "branch circuits" I would guess that it's 1/2".

 

[celtic]

Since he said "branch circuits" I would guess that it's 1/2".

I dunno....I *could* jam 8 #14 THHN's in a 3/8" LFNC...not that I would....but I could according to TC5....that'd be branch circuitS :grin:

 

[infinity]

I dunno....I *could* jam 8 #14 THHN's in a 3/8" LFNC...not that I would....but I could according to TC5....that'd be branch circuitS :grin:

That likely would be a violation of 356.20(A).

 

[Twoskinsoneman]

Thanks guys,

Just out of curiousity can you think of any places the NEC specifically mentions it IS okay to use smaller than 1/2

 

[celtic]

Luminaries and motors...with limitations as Infinity described.

Check the 3xx.20 sections in regards to flexible raceways.


If you can be a bit more specific...we can be a bit more specific.

 

[lordofpi]

Without going through the NEC, I am confident in saying off the top of my head that the following raceways are not permitted in sizes smaller than metric designator 16, trade size 1/2: Thinwall, IMC, GRC, Greenfield, Sealtite, RNC, HDPE, and Smurf. I'm sure LFNC and any others that aren't coming to mind probably follow this rule as well. The only way you will be using < (1/2") knockouts is with a cable assembly of some sort. I hope that was the question that was being asked. :smile:

 

[celtic]

Pi.
Check the 3xx.20 sections in regards to flexible raceways....while the raceway is 3/8", the connector may very well be 1/2" at the threads.

 

[lordofpi]

Pi.
Check the 3xx.20 sections in regards to flexible raceways....while the raceway is 3/8", the connector may very well be 1/2" at the threads.

I think you mean that the other way around, but either way, you snagged me. The raceway (barring fixture whips, which I failed to note) may not go below t/s (1/2), though it very well could have a 3/8 connector, true enough.