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Support of 4 inch square boxes #201465
06/02/11 05:01 PM
06/02/11 05:01 PM
SJT  Offline OP
Joined: Jul 2002
Posts: 241
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

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Re: Support of 4 inch square boxes [Re: SJT] #201468
06/02/11 06:45 PM
06/02/11 06:45 PM
sparkyinak  Offline
Joined: Jul 2007
Posts: 1,329
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

"Live Awesome!" - Kevin Carosa
Re: Support of 4 inch square boxes [Re: SJT] #201469
06/02/11 07:16 PM
06/02/11 07:16 PM
wire_twister  Offline
Joined: Jul 2007
Posts: 265
Georgia USA
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


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Re: Support of 4 inch square boxes [Re: SJT] #201470
06/02/11 08:56 PM
06/02/11 08:56 PM
HotLine1  Offline

Joined: Apr 2002
Posts: 6,936
Brick, NJ USA
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?

Re: Support of 4 inch square boxes [Re: SJT] #201475
06/03/11 07:16 PM
06/03/11 07:16 PM
Tesla  Offline
Joined: Jun 2004
Posts: 1,273
Sacramento, CA
ERICO makes a series of appropriate box supports...

Check them out.



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