You're probably right, but just to rules lawyer this a bit for fun:
Flexible cords and flexible
cables shall be used only for
the following: [...] (9)
Connection of moving parts.
He could mount his panels on plywood on caster wheels, and then prevent excess moment by tying those "moving parts" by chain to cinder blocks.
The rules don't specify that you must have a reason that isn't dumb to make those parts move.
The "400.12 Uses Not Permitted" section gives the list in "400.10" a blanket exemption ("unless specifically permitted in 400.10"), and that's the section that would forbid running the wires through a window.
The rules don't specify that you must have a reason that isn't dumb to make those parts move.
The "400.12 Uses Not Permitted" section gives the list in "400.10" a blanket exemption ("unless specifically permitted in 400.10"), and that's the section that would forbid running the wires through a window.