Is it permissible for a qualified person who services and maintains the facility to "peel out" a power cable from a cable tray and run it down the inside portion of an H beam to a piece equipment? The cable is properly supported as it runs down the column to the equipment, and it's protected by the inside portion of the H beam. Keep in mind that although the cable is unsupported for 5 feet at both ends of the installation, it's properly supported.

A) Yes, but only if the power cable is installed in RMC
B) Yes, if the power cable is TC-ER rated, properly protected from physical damage, and meets all of the requirements of 336.10(7)
C) Yes, but only if the cable is installed in a channel or tray
D) Either A or C

Answer: B)

Per a 2005 change, 336.10(7) was revised to allow the installation of TC-ER rated cable when meeting all of the requirements of this section.

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at necexpert@aol.com.