I recently wired a new laundry room for a family member's renovation project. He already had the electrical materials on hand and all of his boxes attached to the studs, so I ended up installing the electric clothes dryer receptacle (NEMA 14-30 using 10/3 NM-B) in a "deep" 1-gang wall box (22 cu in).
I'm not used to seeing this type of setup done using anything smaller than a 2-gang box, but the receptacle's screw holes were configured for use with either 1-gang or 2-gang. This family member is also a flooring/walling contractor and insisted he'd seen them installed in 1-gangs in new construction on numerous occasions.
The box fill calculations I did show that a single termination of 10/3 + ground is more than fine in a 22 cu in. box, but the receptacle itself takes up an impressive amount of space in the box (not sure if this actually affects box fill requirements, though).
Are there any formal requirements for box size/type for the installation of these receptacles aside from normal box fill requirements?
Best Answer
It's fine in a single gang box if it meets fill reqs and the screws line up without modification. Cover plates may be difficult to find, but they exist.
Use electrical tape over the terminal screws if it makes you feel good. I do when the box is metal.