Illustrated Catastrophes: Sunscreen Won’t Help These Cables

All references are based on the 2023 edition of the NEC.

Sunscreen Won’t Help These Cables

Sunlight has taken its toll on these cables. The jacket has cracked and crumbled off, leaving the insulated conductors exposed directly to the sun, rain, snow, and ice. This type of damage certainly did not happen overnight. These cables were most likely installed before the 2023 Code, but it is a great example of the damage that can happen from long-term exposure to the sun. For power-limited cables installed in corrosive, damp, or wet locations, Sec. 722.3(J) requires power-limited cables to comply with the applicable requirements in Secs. 110.11, 300.5(B), 300.6, 300.9, and 310.10(F). Section 110.11 would apply to this outdoor wet location and prohibits conductors and equipment from being located in damp or wet locations unless identified for use in the operating environment.

Section 300.6 is also applicable and requires cable sheathing, fittings, supports, and support hardware (among several other items) to be made of materials suitable for the environment in which they are installed. Where nonmetallic cable jackets and other nonmetallic equipment are exposed to sunlight, Sec. 300.6(C)(1) requires the materials to be identified as sunlight resistant or listed as sunlight resistant. Lastly, Sec. 722.179(A)(11) requires nonmetallic cables used in wet locations to be listed for use in wet locations and marked either “wet” or “wet location.”

Improper Use of EMT and Flexible Cord

Electrical metallic tubing (EMT) cannot be used to support boxes. Period. End of story.

Section 358.12(2) prohibits EMT from being used for the support of luminaires or any other equipment except a conduit body no larger than the trade size of the EMT. Whomever installed the wiring and lights to light up this parking lot sign supported two boxes using EMT. Facing the weatherproof lampholders up to the sky is a violation of Sec. 110.3(B) as there are markings on the side stating to aim horizontally or below. In this position, they could fill up with rainwater or melting snow, causing significant damage to the equipment.

Neither the round box at the end of the EMT nor the box in the middle of the I-beam is supported correctly and in accordance with any of the requirements in Sec. 314.23(A) through (H). Using flexible cord as a permanent wiring method between two boxes is a violation of Sec. 400.12(1). Using LFMC or LFNC instead of flexible cord would have been two other Code-compliant options. Securing the flexible cord to the EMT installed on the building is a violation of Sec. 358.12(2) as well as Sec. 300.11(C).