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Posted By: SJT Support of 4 inch square boxes - 06/02/11 09:01 PM
Would it be allowed to support a 4 inch square (1900) box with threaded rod? The box contains a single receptacle, (110v)
The threaded rod is approx. 10' long, suspened from the steel work above. The box does sway (move) with the rest of the conduit when disturbed.
In the NEC, they talk about the box shall be securely fastened. Does that mean, no movement at all?
Then the job would need extra bracing. There are approx. 20 boxes. There is 3/4" rigid conduit installed between boxes.
Good Day
SJT
Posted By: sparkyinak Re: Support of 4 inch square boxes - 06/02/11 10:45 PM
Since it is only rigid conduit, you will have to supply some sort of lateral support to prevent swaying. We may need additional info on what your intent is
Posted By: wire_twister Re: Support of 4 inch square boxes - 06/02/11 11:16 PM
You can sleeve the threaded rod with 1/2 emt pipe, tightened up between the top and bottom jamb nuts and it will stiffen it considerably
Posted By: HotLine1 Re: Support of 4 inch square boxes - 06/03/11 12:56 AM
Some additional info:

Is the 3/4 RGC supported? What is the RGC length between boxes?

Are the 20+/- boxes in a straight row? Or what layout?

Posted By: Tesla Re: Support of 4 inch square boxes - 06/03/11 11:16 PM
ERICO makes a series of appropriate box supports...

Check them out.

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