This piece was originally published in the April 2016 issue of ei, the magazine of the electroindustry.
By Jack Lyons, Northeast Field Representative, NEMA
Photovoltaic (PV) system installations around the country have increased tremendously. Installers, inspectors, and designers keep their eyes open for any National Electrical Code® (NEC) changes relevant to these systems.
Code adoptions are critical in order to enforce changes and create safer installations. These changes are based on practices that are constantly evaluated. Wiring techniques and electrical products that provide protection from shock and fire are addressed in Article 690 (Solar PV Systems) of the NEC. Electrical personnel are not the only stakeholders who contribute to the safety of a solar system; thus, there have been many changes to fire codes over the past few cycles.
Firefighters’ fear of exposure to voltages associated with a solar panel array, even when the system is disconnected, led to an NEC requirement for rapid shutdown of panel output at the array level. Fire codes also address the array layout of PV panels to allow responders to move around the roof of a building on fire. Responders may only be able to vent a rooftop if they can get to the affected area.
Builders must also be involved, to evaluate both the strength of a roof for an array and the integrity of the roofing materials. The structural design provides the safe support of the complete array, while the life of the roofing materials helps eliminate the need to remove the array for roof replacement, which would create unnecessary hazards. Proper roof design based on current building codes ensures sound installations for future use.
Reflecting Industry Trends
We have seen more than 100 changes to Article 690 between the 2011 and 2014 versions. Using data regarding past practices and experiences with fires and failures of PV systems, the subject material experts who make up the NFPA Code Making Panel for Article 690 have adjusted, tweaked, and created new rules that provide better safety for the stakeholders involved around any PV installation. NEMA representatives on this panel provide the manufacturers’ perspective during these proceedings.
These changes are critical for installers, inspectors, and designers to understand and implement. In states that have not kept up with adoption, there may be unintended consequences. Serious challenges position PV businesses that want to meet maximum safety installation requirements against those that simply install to a current code that provides for minimum safety installation requirements. This leaves the conscientious business owner at a market disadvantage.
NEMA members’ products provide some of the latest safety features required by the newest code edition.
A few product areas that manufacturers provide to the industry that also enhance the safety of PV installations include cable systems and wiring methods; marking and labeling in accordance with ANSI Z535; and enclosures, switches, and disconnects that meet the requirements of Article 690.
These efforts, combined with the field reps challenging postponement of code adoption in their territories, assure consumers that safety enhancements are met in all PV installations.