question about box supporting 314.23 (e) - Contractor Talk - Professional Construction and Remodeling Forum

CNC · 08-07-2008, 12:37 PM

in article 314.23 (E) its states

raceways supported enclosures without devices need to have threaded bodies, OR hubs identified for this purpose. Now a NEMA box within the correct size, supported by 2 emt raceways, with rain tight connectors do it? WHere do i find hubs identified for it.

We have to fix a bunch of boxs, that got stubbed up to an attic, and then a junction box got added, and MC was run directly out of it. Most of the boxs are only stubbed up 10 or so inches, with one pipe. Its a 16 inch center wood framed attic so there isnt much to mount to. i guess ill have to mount them on uni strut, any quick tips?

Magnettica · 08-09-2008, 03:24 PM

Quick tips?

Yes, forget about the unistrut - that's for industrial type stuff and looks lousy in a home. Use wood (perhaps plywood or whatever works) and fasten it across the floor joists. Mount j-boxes to that. I hope I understood your question.

vocivictim · 10-14-2008, 01:18 PM

EMT cannot be used to support an enclosure. Only rigid or IMC. The only listed hubs I know of are Meyers hubs and will not work for this installation. Hope this helps!!

Celtic · 10-14-2008, 04:00 PM

Quote:

Originally Posted by CNC

.... supported by 2 emt raceways, with rain tight connectors do it? WHere do i find hubs identified for it.

You don't.

Lets look at the NEC:

Quote:

314.23(E) Raceway Supported Enclosure, Without Devices,
Luminaires (Fixtures), or Lampholders.
An enclosure that does not contain a device(s) other than splicing devices
or support a luminaire(s) [fixture(s)], lampholder, or other equipment and is supported by entering raceways shall not exceed 1650 cm3 (100 in.3) in size. It shall have threaded entries or have hubs identified for the purpose. It shall be supported by two or more conduits threaded wrenchtight into the enclosure or hubs. Each conduit shall be secured within 900 mm (3 ft) of the enclosure, or within 450 mm (18 in.) of the enclosure if all conduit entries are on the same side.

You can't thread EMT, so it will never be "wrenchtight".

Even the exception doesn't help...

Quote:

Exception:
Rigid metal, intermediate metal, or rigid nonmetallic conduit or electrical metallic tubing shall be permitted to support a conduit body of any size, including a conduit body constructed with only one conduit entry, provided the trade size of the conduit body is not larger than the largest trade size of the conduit or electrical metallic tubing.

A box is not a conduit body.

A wood frame to act as support is the easiest choice.