A mere ½ in. closer, and this screw could have done some serious damage to the EMT and the conductors inside. This is a great example of why Sec. 300.4(E) requires raceways, cables, and boxes to be installed and supported to provide no less than 1½ in. of separation between the lowest surface of the metal-corrugated sheet roof decking and the top of the raceway cable or box. //

I will certainly give this installer credit for installing the Class 2 control wires in a raceway separate from the power wires feeding this air-conditioning equipment. Section 725.136 generally requires Class 2 and Class 3 circuits to be kept separated from power conductors and provides several methods to achieve this separation. However, the choice to install liquidtight flexible nonmetallic conduit (LFNC) in this outdoor, sun-drenched area may need to be reviewed. Section 300.6(C)(1) requires nonmetallic raceways exposed to direct sunlight to be listed or identified as being sunlight resistant. Section 356.10(3) does permit LFNC to be installed in outdoor locations if the LFNC is listed and marked for this purpose. According to the product standards, LFNC suitable for installation outdoors is marked “outdoor.”