All references are based on the 2020 edition of the NEC.
Lean On Me
This tilted service mast is trending toward a complete failure. The weight and tension from the service-drop conductors are causing the rigid metal conduit (RMC) to bend significantly. While the NEC does not specify a minimum size requirement for raceways used as service masts to support service-drop conductors or overhead service conductors, Sec. 230.28(A) requires these masts to be of adequate strength or otherwise be supported by guy wires or braces to safely withstand any strain caused by the service-drop conductors or overhead service conductors. Many electric utilities also have specifications for installations of masts where used to support their service drop conductors. Perhaps some guy wires or braces should have been used on this installation to provide additional strength and support. When masts are used for support of overhead branch circuit or feeder conductors, Sec. 225.17(A) has the same requirements for mast strength and support as Sec. 230.28(A). One more concern I have is the lack of an expansion fitting on the horizontal section of rigid PVC conduit below the garden hose. Section 352.44 requires expansion fittings to be used where thermal expansion and contraction would cause a length change of ¼ in. or more in the conduit.
Thar’ She Blows
I discovered this blown-up situation when the wallboards were removed from this wall due to flood damage. The armored cable feeder was damaged during the original construction of this building when the drywall installer ran a screw right through the metal stud and into the cable. Amazingly though, the apartment being fed by this feeder was not experiencing any power problems. In fact, this cable was still energized when I spotted this problem. Section 320.17 requires Type AC cable to be protected in accordance with Sec. 300.4(A), (C), and (D), where the cable is installed through or parallel to framing members. Section 300.4(A) applies to cables run through wooden framing members, Sec. 300.4(C) applies to wiring behind removable panels, and Sec. 300.4(D) applies to cables run parallel to framing members or furring strips. I suppose we could cite Sec. 300.4(D), too, since there is some wood framing installed in this wall to provide rigid backing for securing the handrails that were installed in this common hallway. Section 300.4(D) requires the cable to be installed at least 1¼ in. from the nearest edge of framing members where screws or nails are likely to penetrate. Where that distance cannot be maintained, a steel plate at least 1/16 in. thick must be used to provide protection for the cable.
