ECN Forum Forums Code Related Discussion NEC & other Code issues Flexible metal and Liquidtight Flexible Metal Conduit Max Lengths for Flexibility

NEC Art. 350 & 351 allows these wiring methods to be unsupported in lengths up to 3 feet at terminals where flexibility is required (such as at motors). Article 300-22(b) permits these wiring methods in lengths up to 4 feet to connect "physically adjustable equipment and devices in ducts and plenums". Does the location specific 300-22 (such as a fan motor in an air handler's casing) supercede the general requirements of 350/351 and allow UNSUPPORTED 4 foot lengths in this application?

Steve,

I was hoping that someone familiar with those code sections would reply. If it was my job I would provide a support so that the unsupported part is no longer than 3 feet. That, to me, would seem to satisfy everything. It seems to me that the 4 ft length mentioned is the total length allowed under those circumstances period. And since support (or lack of it) is not mentioned I would say that the provisions of 350/351 would apply and that 3 ft maximum unsupported length would be the rule.

Under 300-1(a) it says "This article covers wiring methods for all wiring installations unless modified by other articles"
I would say that 350/351 has the last word.

Any other opinions on this?

Bill