I've done it as a mater of routine .... but some folks have run into issues with their AHJ - who wants a hinged door.
IMO, there's no code issue, and trying to apply 'listing and labeling' is quite a stretch. Heck, I've even had folks object to cutting holes in the boxes, rather than using the factory KO's. Go figure.
It's just that I had an inspector in the LA area tell me I couldn't enclose a contactor in a pull box because the box wasn't listed for that use. It was a long time ago and I never did find the code section. I guess it doesn't exist. Thanks for the help!
It was just a regular pull box with the contactor mounted using tech screws. I see what you're getting at though. If there is a specific box made for that contactor then it seems reasonable that the inspector would want the approved box to be used. In this case I'm looking at a 5 day lead time if I want it in a specialized contactor box. Uhggg!!