Hint: “gimme” some support here
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Using flexible wiring methods such as flexible metal conduit (FMC) is a good choice when it comes to wiring equipment such as motors, compressors, transformers, generators, and other types of equipment that may vibrate, twist, or otherwise have some movement during normal operation. Whatever type of wiring method you decide to use, be sure it complies with the support requirements outlined in the NEC.
Section 348.30(A) requires FMC to be securely fastened within 12 in. of each conduit termination and supported and secured again at a maximum of 4½ ft intervals. The FMC in this photo is not secured within 12 in. of the conduit terminations. For installations where flexibility is needed, such as this motor, Sec. 348.30(A), Exception No. 2, allows for alternative support options. For trade sizes ranging from ½ in. to 1¼ in., the FMC can be installed unsupported for lengths up to 3 ft from the last point where it is securely fastened. The installer of this FMC chose to install zero supports at the 3-ft mark. This length of FMC is closer to 5 ft with no supports other than the connectors at each end.
About the Author
Russ LeBlanc
Owner
Russ started in the electrical trade as an apprentice in 1985. He worked his way up to become a Journeyman Electrician and then eventually became a Master Electrician and Licensed Construction Supervisor. In 1999 Russ become an Electrical Instructor for The Peterson School of Engineering in Massachusetts where he developed his passion for teaching, and quickly became Department Head of Electrical Instruction. Russ has taught thousands of apprentices, electricians, engineers, inspectors, and other electrical professionals during his career as an instructor. He continues to provide electrical professionals with Electrical Code seminars, Arc-Flash Awareness training seminars and educational material through his LeBlanc Consulting Services in North Reading, MA whose specialty is educating electricians. He has been an active member of the NFPA Electrical Section and has authored hundreds of National Electrical Code proposals and comments which have become Code rules to improve the safety for the electrical industry. Russ is also an IAEI certified Electrical Inspector.
Please visit www.russleblanc.net for more information.