Periodically, I receive requests to address issues about installations of low-voltage lighting systems and regular lighting around swimming pools. I decided this issue would be best addressed as an article in this magazine. A review of the safety issues dealing with lighting in and around a pool will provide a better understanding of the key construction requirements and will help highlight the protection required for these lighting systems.

In the National Electrical Code (NEC), regular voltage lighting around a pool is covered in Section 680.22 of Article 680 for permanently installed pools; it must be reviewed. Article 411 covers low-voltage lighting system installations, operating at 30 volts (V) or less. Low-voltage lighting systems are defined in 411.2 as a lighting system consisting of an isolating power supply, the low-voltage luminaries and the associated equipment that are all identified for that use. The output circuits of the power supply are rated for not more than 25 amperes and operate at 30V (42.4V peak) or less under all load conditions.

Lighting systems operating at 30V or less shall be listed as a complete system with the luminaires, power supply and luminaire fittings listed for use as part of the same identified lighting system. A lighting system assembled from the following listed parts shall be permitted: low-voltage luminaires, low-voltage luminaire power supply or a Class 2 power supply, low-voltage luminaire fittings, a cord (secondary circuit) for which the luminaires and power supply are listed for use, and low-voltage cables, conductors in conduit, or other fixed wiring method for the secondary circuit.

Section 411.4(B) covers installation of low-voltage lighting systems for pools, spas, fountains and similar locations. Where installed, these low-voltage lighting systems must not be less than 10 feet horizontally from the nearest edge of the water, unless otherwise permitted by Article 680. Section 680.22(C) provides requirements for all luminaires and lighting outlets of any voltage level for indoor and outdoor pool areas.

For outdoor locations, any luminaire or lighting outlet located directly above the pool or within 5 feet horizontally from the inside walls of the pool must be installed at a height of not less than 12 feet above the maximum water level of the pool. Where luminaires and lighting outlets already exist before the installation of the pool and are located less than the 5 feet horizontal distance required in the previous sentence, the luminaires and lighting outlets must be mounted not less than 5 feet above the surface of the maximum water level of the pool, must be rigidly attached to the existing structure, and shall be protected by a ground-fault circuit interrupter (GFCI). Low-voltage lighting luminaires supplied by an isolating power supply, such as a 120V to 12V low-voltage transformer, cannot be protected by a GFCI on the low-voltage secondary side, since low-voltage GFCIs are not available and GFCI protection on the primary side does not provide the appropriate protection of the low-voltage luminaire or lighting outlet.

Any luminaire or lighting outlet of any voltage installed within the area extending between 5 feet and 10 feet horizontally from the inside walls of a pool shall be protected by a GFCI, unless installed not less than 5 feet above the maximum water level and rigidly attached to the structure adjacent or enclosing the pool. Again, GFCI protection on the low-voltage side of the power supply is not possible, and GFCI protection on the primary side does not provide the required protection for the luminaire or lighting outlet. The only low-voltage luminaires permitted within proximity of the edge of the pool are the low-voltage underwater luminaires permitted by 680.23(A)(2).

Low-voltage underwater luminaire transformers must be listed as a swimming pool and spa transformer. This transformer is required to be an isolated winding-type transformer with an ungrounded secondary that has a grounded metal barrier between the primary and secondary windings. The primary of this transformer is rated at 120V with the maximum secondary rating of 15V and an overall rating of 1,000 VA. These transformers are provided with integral overload protection. This type of transformer is specifically listed for underwater luminaires and not listed for aboveground low-voltage luminaires.

Section 680.23(C) could be changed for the 2014 NEC to permit a special isolation transformer with a ground shield, similar to the underwater luminaire transformer, for aboveground low-voltage lighting systems in proximity to the edge of a swimming pool. Until the change is submitted and processed, low-voltage lighting must not be located closer than 10 feet horizontally from the edge of the pool or 12 feet above the pool.


ODE is a staff engineering associate at Underwriters Laboratories Inc., based in Peoria, Ariz. He can be reached at 919.949.2576 and mark.c.ode@us.ul.com.