Change methods at box, ?s

[tshephard]

MWBC to detached shed (following the garage rules is OK).
4 #10's in 3/4 PVC pipe stubbed up, want to change to NM inside shed,
at a 3 gang box for DPST disconnect switch, and 2 GFI receptacles.

I hope to either:
add a single hole in bottom of blue NM style box to bring in PVC, and use internal NM clamps to exit, or
add NM clamps to PVC glue/pipe box (they are small fortune), or
a better suggestion?

Basically question is: Is it OK to add a pipe hole to a fairly large blue NM box?
I would adapt in - PVC pipe adapter, locknut inside - not glued up.

I'm trying to save money/transition, have no exposed metal before the GFIs, and of course pass on first look!

THX

 

[infinity]

So basically the question is can you make a hole in a plastic box to enter a raceway?

 

[tshephard]

Yes, but in particular a blue, NM style box with no identified knockouts.

 

[Dennis Alwon]

Is this what you are talking about but perhaps larger

 

[tshephard]

That style. yes

 

[Dennis Alwon]

Well the box is not approved for the purpose so you could get red tagged for it.

 

[Buck Parrish]

That style. yes

No, That box is not allowed to have additional holes

 

[Buck Parrish]

You need one of these with knockouts . But watch your square inch box volume. I would use metal.

 

[Dennis Alwon]

Use a deep 4" sq. box and install a dp switch in the box as your disconnect for the building.

 

[Little Bill]

You need one of these with knockouts . But watch your square inch box volume. I would use metal.
View attachment 2561168

Those KOs in that type box are for ENT (Smurf tube). I don't think they're listed for metal conduit.

 

[tthh]

?? Carlon 3/4 in. 32 cu. in. Type-2FSE FS Box

 

[Dennis Alwon]

Those KOs in that type box are for ENT (Smurf tube). I don't think they're listed for metal conduit.

He is using PVC. I don't see why that wouldn't work. It wouldn't be my choice but I think it is compliant

 

[Little Bill]

He is using PVC. I don't see why that wouldn't work. It wouldn't be my choice but I think it is compliant

I didn't catch the PVC part.

 

[Buck Parrish]

Those KOs in that type box are for ENT (Smurf tube). I don't think they're listed for metal conduit.

I would not use it either. Looks like a Mickey Mouse box. Perhaps that's why they call it Smurf.

 

[jap]

Does the pipe stub up inside or outside of the shed?

JAP>

 

[tshephard]

Pipe is outside so far... LB 90 LB LB to get in and up.

When I look at 1 gang, PVC glue in boxes, they seems to have screws posts, strength bends, etc, so as to not have 1 inch clear space at top for hole, clamp, or lock-nut.
Considering PVC glue in 'C' box with stub up 'for protection' to near base of 2 gang blue box, with NM inside, having transitioned at the switch.

 

[jap]

I'd put a cheap AC pullout on the outside of the shed to use as a disconnect, extend the THHN out of the back of that into the inside to the switch that (you're eventually going to want for a light) and receptacles wherever you want them.

JAP>

 

[tshephard]

Anyone think this out of compliance?

Glued up PVC system, THWN to FSC box (large volume) with disconnect DPST, PVC pipe (less than 24 in) out of that box to very near a new work blue box with 2 GFIs - NM in that PVC pipe, un-clamped until blue box internal grip. Blue box is NOT breached for pipe, NM guided and protected by short PVC.

 

[Buck Parrish]

Could or would you provide a pic? I'm sure we could find something non-compliant.

 

[tshephard]

Sure!
What I'm finding is:
boxes for devices have junk inside, posts for switches and covers, and little clear area for a clamp for instance, or
plain boxes (obviously for knockouts and such) but then they no posts for mounting device.
Would really like to have only plastic exposed until exiting the GFIs.