Sump pump connection
My latest project in the basement remodel was changing the pedestal sump pump to a below-ground type. The pump is now entirely below ground with a heavy-duty aluminum grate covering the pit. A trench several inches long was cut out of the slab to allow the PVC drain pipe to slip under the stud wall sill plate (it runs right against the pit). The cord for the pump runs in that same trench to get it behind the stud wall, so no wiring can be seen once the grate is on and the sheetrock is up.
The access panel for the wiring is going to be directly above this trench. I was initially going to cut the plug off an wire it directly to its own GFCI circuit, but I was "informed" that NEC requirements say sump pumps are not allowed to have a direct connection to a line, i.e., they must use a plug.
So, two questions:
1) Is this an actual NEC requirement that I simply cannot find (a section/paragraph # would help me find it in my little red book)?
2) If so, would it be legal to use a double-gang box, turn a socket sideways within the box, plug the pump in without modification of the plug/cable, and cover the whole shebang with a blank plate?