Illustrated Catastrophes: Pool Chemicals Causing Problems

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

Pool Chemicals Causing Problems

I think this photo shows us a great example of how badly electrical equipment can be damaged by corrosive pool chemicals. The aluminum box is corroding into a bluish-white powder, and the galvanized metal conduits are rusting away. This is typical of what can happen to certain metals when exposed to strong oxidizing agents like chlorine.
For general installations, Sec. 300.6 requires raceways, boxes, fittings, supports, support hardware, and other equipment and components to be made of materials suitable for the environment in which they are to be installed. For installations in corrosive environments at swimming pools,

Sec. 680.14(A) provides a short list of permitted wiring methods: RMC, IMC, PVC conduit, RTRC (fiberglass conduit), and LFNM conduit. For other equipment, such as boxes and enclosures, Sec. 680.14(B) requires them to be suitable for use in corrosive environments or be installed in identified corrosion-resistant enclosures. Equipment specifically listed for pool and spa use is also permitted for this use. While RMC is permitted here, perhaps stainless-steel or PVC-coated RMC might have held up better against the corrosion. Also, while Sec. 680.14 does not specifically prohibit installing aluminum boxes here, installing aluminum conduit and aluminum tubing is prohibited. A stainless-steel box or nonmetallic box may have been a better choice here.

Sad Wiring on This Sign

I’m not sure what those cable ties are for, but I think they were used to attach a banner to this signpost. In any case, spotting those giant cable ties is what drew me over to this installation, where I discovered the cover missing off of the box installed here. Section 314.15 requires completed box installations to have a cover, faceplate, lampholder, or luminaire canopy installed to cover the box and protect the wiring and splices. These wires and splices are exposed to sun, rain, ice, and whatever else Mother Nature can throw at them. The wire connectors have faded and are becoming dried and brittle from being exposed to the elements. The same can be said about the conductors. The missing cover and damaged wires/wire connectors can increase the chances of people getting shocked since this equipment is fully accessible to the general public. Another problem here is lack of support for the RMC and boxes for the luminaires. The supporting of the RMC does not comply with Sec. 344.30. The boxes installed in the RMC for mounting of the luminaires do not comply with any of the box supporting requirements found in Sec. 314.23(A) through (H).