Family swimming pools have certainly changed. Remember those temporary abovegrounds, usually about 3 feet deep? Well, now the standard is an in-ground pool with all the bells and whistles. I just read about a family pool in Arizona with a construction price tag over $1 million!

How could a family swimming pool possibly cost that much, and what extras could be designed into it? A person could only guess at what goes into a swimming pool for that price. Although most people would never be in the market for a pool that extravagant, Article 680 provides the safety installation requirements for the simplest to the most elaborate pools anyone could design.

A common, relatively inexpensive addition that can be installed on an existing swimming pool is an electrically operated pool cover, which I discussed in last month’s column (see “Special Swimming Pool Requirements” at ECmag.com). 

Some extra features that can be installed include underwater audio, gas torch lighting and waterfalls that can turn a normal pool into an oasis for day and night relaxation. When it comes to the safe installation and requirements for these types of applications, some can be added fairly easily to an existing pool and others require more elaborate modifications.

Underwater audio equipment

A discussion on underwater audio systems requires a brief explanation on acoustics and the “science of sound.” Air is not a good sound transmitter because gas molecules occur in a very low density. Liquids and solids are denser and therefore better conductors, allowing sound waves to travel faster and further. Installing audio speakers directly in the water provides better sound for swimmers. I have not experienced this phenomenon, but have read that the sound quality in water is very good.

Section 680.27 requires all underwater audio equipment to be identified as such. Each speaker must be mounted in an approved metal forming shell, the front of which is enclosed by a captive metal screen (or equivalent) that is bonded to, and secured to, the forming shell by a positive locking device that ensures a low-resistance contact. The forming shell locking device requires a tool to open it for speaker installation or service. 

The forming shell must be installed in a recess in the pool wall or floor. The forming shell and metal screen must be of brass or other approved corrosion-resistant metal. The shell must also include provisions for terminating an 8 AWG copper conductor for bonding purposes.

Wiring methods for speakers must be rigid metal conduit of brass or other identified corrosion-resistant metal, liquidtight flexible nonmetallic conduit (LFNC), rigid polyvinyl chloride (PVC) conduit or reinforced thermosetting resin (fiberglass) conduit, and must extend from the forming shell to a listed junction box or other enclosure as provided in 680.24. 

Where rigid PVC conduit, reinforced thermosetting resin (fiberglass) conduit or LFNC is used, an 8 AWG insulated solid or stranded copper bonding jumper must be installed in this conduit. The bonding jumper must be terminated in the forming shell and the junction box. The termination of the 8 AWG bonding jumper in the forming shell is required to be covered with, or encapsulated in, a listed potting compound to protect such connection from the possible deteriorating effect of pool water.

Features with low-voltage ignitors

Section 680.22(B)(7) covers listed low-voltage, gas-fired-luminaires, decorative fireplaces, fire pits and similar equipment using low-voltage ignitors that do not require grounding. These devices must be supplied by listed transformers or power supplies that comply with 680.23(A)(2) with outputs not exceeding the low-voltage contact limit and are permitted to be located less than 5 feet from the pool’s inside walls.

Section 680.23(A)(2) requires the transformer or power supply to be listed, labeled and identified for swimming pool use. The transformer or power supply must incorporate either a transformer of the isolated winding type with an ungrounded secondary that has a grounded metal barrier between the primary and secondary windings, or one that incorporates an approved system of double insulation between the primary and secondary windings. The grounded metal barrier between the primary and secondary windings prevents the likelihood of a primary to secondary short.

Whether you spruce up an existing pool or build a new one with these incredible features, follow the safety requirements outlined in Article 680.

stock.adobe.com / Tom