Your most pressing National Electrical Code (NEC) questions
answered All questions and answers are based on the 2011 NEC. Q.
Does the Code allow the installation of cord-connected equipment
above a suspended ceiling? A. Unless specifically permitted in
400.7, flexible cords must not be concealed by walls, floors, or
ceilings, or located above suspended or dropped ceilings
[400.8(5)]. Flexible cords are permitted under a raised floor
(with removable panels) used for environmental air, because this
area isn’t considered a concealed space. See the definition of
“Exposed” in Art. 100.Receptacles are permitted above a
suspended ceiling, but a flexible cord isn’t. Why install a
receptacle above a ceiling if the flexible cord isn’t permitted
in this space? Because the receptacle can be used for portable
tools; it just can’t be used for cord- and plug-connected
equipment fastened in place, such as a projector (click here to
see Figure). Q. Is a supplemental grounding electrode for a
single rod, pipe, or plate electro