I need to mount a 100a switch over an existing single gang box in a wall.The conduit is 1.25 coming into the box.I have never mounted one over a box before.I thought I could just nipple it and be done. Any code issues or helpful hints would be appreciated.
I'd need a lot more info to respond to this, and a pic wouldn't hurt.
Is this an abandoned box, or are any wires in the box to enter the disconnect? I can't imagine 100-amps worth of conductors fitting a single-gang box.
If I had to venture a guess now, I'd say to mount an extension box over the existing box, mount the disconnect to one side, and nipple between them.
Sorry,I see how I needed to be more clearer.There is an empty 1.25 coming into a 4 11/16 box with a single gang plaster ring on it.I need a 70 amp circuit there with a disconnect.There is sheetrock over the box.Thanks in advance.
Access to the box in the wall is an issue. I wouldnt consider needing to remove a disconnect to access a box as accessible. Larry's suggestion is how I do it. An extension box then go to the disconnect.
I see your point.But,could I mount it over the plaster ring? Is this a code requirement?The wires would pass thru the box to the disconnect.I am more concerned with the code issue more than the convienance of mounting it.Thanks again.
No, I don't think that you could not mount the disconnect over the box and remain code compliant. You would need to maintain accessibility to the box beneath without removing the disconnect. I don't think there would be room enough in the disconnect to cut a 2-1/4 by 4 inch hole to get that access, nor would the listing allow you to modify the box that much. Is it possible to open the wall enough to remove the box, attach an offset bend, and enter the disconnect directly?
Maybe I've been missing something in this discussion, but IF there are no splices or connections of any kind in the box (i.e., the wire simply passes through the box on its way to a bushing on the rear of the disconnect), I don't see any problem at all.
Even if new conductors needed to be pulled through at a later time, I would think the box itself would allow enough bend radii to get 'em in.
Thoughts?
The code doesnt make an exception for a junction box that has splices or not. All junction boxes must be accessable.
Even so, What about your ground wire bonding both boxes, theres a splice for you.
Is the disconnect part of "the building finish"?
Accessible (as applied to wiring methods). Capable of being removed or exposed without damaging the building structure or finish or not permanently closed in by the structure or finish of the building.
Yeah,that is kinda my question/quandry.Is the disco considered the building?I also wouldn't splice the ground,just wrap the wire around the grd screw then go to disco(still a termination?).I am not looking to get around the code,just looking for some insight into the code issues.I have done similar installs on A/C units,but they are accessible.Thanks for the replies.
"314.25 Covers and Canopies.
In completed installations, each box shall have a cover, faceplate, lampholder, or luminaire (fixture) canopy, except where the installation complies with 410.14(B).
410.14 Connection of Electric-Discharge Luminaires (Lighting Fixtures).
(B) Access to Boxes. Electric-discharge luminaires (lighting fixtures) surface mounted over concealed outlet, pull, or junction boxes shall be installed with suitable openings in back of the fixture to provide access to the boxes."
The way I read this is we have to cover the box with a cover, faceplate, lampholder or luminaire. A disconnect is not of these.
You may say, "well, it doesn't forbid using the disconnect..."
And I would reply, "it doesn't forbid using a sheet of cardboard either. Would you use cardboard?"