4S boxes, come out of box with 12-3 SO, leave some slack, then a kellums grip hanging from joist. The cord drop could be moved depending on length of slack. Can do this with a drop ceiling, go to a Costco bakery, its how they power the mixers and such
It was always enforced in my area, that chords were not allowed to pass through drop ceilings. A box is always required in the drop ceiling, with a Chapter 3 wiring method supplying it from above. Then attach your chord drop to a plate mounted to the box. Strain relief chord connectors attached to each box.
I normally used bus drop cable and fittings, since I have those in stock, and I believe less expensive when bought by the carton, as compared to SO cable. Oftentimes we would attach the lower outlet box to the machine or work surface for stability. A 4 square box has plenty of sharp corners, and can be a hazard swinging around when disturbed. Not to mention, hard to attach an equipment chord to a box swinging in free air. It used to be a requirement that FS boxes with a hub were required for pendant boxes, but I no longer see that in the 2017 NEC. FS boxes are stronger and have smooth rounded corners which makes them more suitable for free hanging boxes, less chance for injury from the sharp corners of a 4" sq box.
400.12 Uses Not Permitted. Unless specifically permitted in
400.10, flexible cables, flexible cord sets, and power supply
cords shall not be used for the following:
(1) As a substitute for the fixed wiring of a structure
(2) Where run through holes in walls, structural ceilings,
suspended ceilings, dropped ceilings, or floors
(3) Where run through doorways, windows, or similar openings
(4) Where attached to building surfaces
Exception to (4): Flexible cord and flexible cable shall be permitted to be
attached to building surfaces in accordance with 368.56(B) .
(
5) Where concealed by walls, floors, or ceilings or located
above suspended or dropped ceilings
Exception to (5): Flexible cord and flexible cable shall be permitted if
contained within an enclosure for use in Other Spaces Used for Environmental
Air as permitted by 300.22(C)(3).
(6) Where installed in raceways, except as otherwise permitted
in this Code
(7) Where subject to physical damage
Though not applicable in
Etanuye's case, I always try to use the methods and materials approved for busway drops. If it's sturdy enough for industrial use, should be more than adequate for most other uses.
368.56 (B) Cord and Cable Assemblies. Suitable cord and cable
assemblies approved for extra-hard usage or hard usage and
listed bus drop cable shall be permitted as branches from
busways for the connection of portable equipment or the
connection of stationary equipment to facilitate their interchange
in accordance with 400.10 and 400.12 and the following
conditions:
(1) The cord or cable shall be attached to the building by an
approved means.
(2) The length of the cord or cable from a busway plug-in
device to a suitable tension take-up support device shall
not exceed 1.8 m (6 ft).
(3) The cord and cable shall be installed as a vertical riser
from the tension take-up support device to the equipment
served.
(4) Strain relief cable grips shall be provided for the cord or
cable at the busway plug-in device and equipment terminations.
Exception to (B)(2): In industrial establishments only, where the conditions
of maintenance and supervision ensure that only qualified
persons service the installation, lengths exceeding 1.8 m (6 ft) shall be
permitted between the busway plug-in device and the tension take-up
support device where the cord or cable is supported at intervals not
exceeding 2.5 m (8 ft).
Sky-Tie
Strain Relief Wire Mesh Chord Grip
Bus Drop Cable
