Pool Design article by Paolo Benedetti, SWD Master
Prior versions of the National Electric Code (NEC) forbid the installation of low voltage landscape lighting within 10 feet of the water's edge. Changes in the 2014 NEC will allow future landscape lighting installations to be located less than 5 feet from the water's edge, with certain conditions.
2014 NEC Changes
First of all, the light fixture must be of a design that does not require GROUNDING (that third green internal conductor in the power cord). The new provision does not address metal light fixtures, but assume that if it is metal, that it will need to be externally BONDED to the grid. Bootleg or homemade bonding attachments are not permitted. If a bonding lug is not provided by the manufacturer, then that fixture is probably not permitted. The conductors must be ran inside of a conduit - direct burial wiring near the pool is forbidden elsewhere in the NEC. Granted, at the end, the conduit must stub up to allow the wire to exit. A compression seal on the end of the conduit will secure and seal the cord's exit.
Buried wire nuts or underground landscaping type of connections are also forbidden. All of the electrical connections must terminate in an approved pool lighting junction box. A typical above grade pool lighting junction box would work fine. One can also use an in-deck junction box, provided it is filled with re-enterable potting compound to prevent the entry of water.
The transformer must be specifically rated and listed for low voltage pool lighting (not just fountains). If you utilize a transformer designed for underwater 12 volt pool lighting, then you're guaranteed success. It must also be powered by a GFCI protected circuit.
Local Adoption - Lead Time
Thought the 2014 NEC has been approved on the national level, regional and local authorities usually operate on versions that are 1 or 2 generations older. This is because government councils have yet to adopt the current versions. Local authorities have the options of not accepting code changes or making the code more restrictive. So, before specifying or installing lighting close to the water's edge, be sure to check with the local building department.
NEC 2014, Section 680.22(B)(6) states: “Low-Voltage Luminaires. Listed low-voltage luminaires not requiring grounding, not exceeding the low-¬voltage contact limit, and supplied by listed transformers or power supplies that comply with 680.23(A)(2) are permitted to be located less than 1.5 m (5 ft) from the inside walls of the pool.”
NEC 2014, Section 680.23(A)(2) states that transformers used for low-voltage lighting around pools shall incorporate isolated windings with an ungrounded secondary and a grounded metal barrier between the primary or secondary or double insulation between the primary and secondary windings and shall be listed for swimming pool lighting.
Paolo Benedetti, SWD Master
Aquatic Technology Pool & Spa
PO Box 130
Morgan Hill, CA 95023
T (408) 776-8220