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Friday, August 19, 2022
Question:
Does a 66" piece of 3/4" PMC with (3)# 10 THHN conductors and a #10 ground that connects a safety switch to a dry type transformer require any supports? It is not above a ceiling.
A
Answer:
Hello CQD Submitter, At least one means of support would be required, Section 348.30(A) Ex No.2 provides guidance on the securing and supporting of FMC:
(A) Securely Fastened. FMC shall be securely fastened in place by an approved means within 300 mm (12 in.) of each box, cabinet, conduit body, or other conduit termination and shall be supported and secured at intervals not to exceed 1.4 m (4-1∕2 ft). Where used, cable ties shall be listed and identified for securement and support.
Exception No. 2: Where flexibility is necessary after installation, lengths from the last point where the raceway is securely fastened shall not exceed the following:
(1) 900 mm (3 ft) for metric designators 16 through 35 (trade sizes 1∕2 through 11∕4)
(2) 1200 mm (4 ft) for metric designators 41 through 53 (trade sizes 1-1∕2 through 2)
(3) 1500 mm (5 ft) for metric designators 63 (trade size 2-1∕2) and larger