I have a 4 inch metal junction box with a 3/4" mud ring attached and recessed into the drywall in my garage. I want to connect an air compressor to this junction box directly without using a plug. What do I need in order to close up the junction box and have a hole for a 3/4" flexible conduit to run to the compressor?
Is it as simple as buying a blank metal 2-gang cover plate and drilling a hole in it? Is there something off the shelf that's actually made for this?
Best Answer
I'm not sure for a specfically "2-gang" box. These are made for 4" and 4-11/16 and octagon boxes:
and there are 1-gang "handy-box" covers with a knock-out as well.
A 4" box will take 2 devices, but some 4" boxes are set up with tabs for the devices, while others are set up with corner screws like this plate uses and need a cover to hold devices in place.