This piece was originally published in the June 2017 issue of electroindustry.
Christel Hunter, Director, Codes and Standards, Cerro Wire LLC
The Solar Energies Industry Association (SEIA) reports that more than 42 GW of solar capacity has been installed in the United States as of the end of 2016; SEIA predicts that by 2021 there will be more than 100 GW of solar installed. With the continued demand for solar energy, photovoltaic (PV) wire continues to be a subject of discussion within the NEMA Wire & Cable Section.
The National Electrical Code® (NEC) Article 690 permits the use of listed PV wire for single-conductor applications installed in outdoor, exposed locations and within outdoor tray cables. When PV wire is used in a conduit system, the designer and installer must use the outer diameter values provided by the wire manufacturer to calculate conduit fill, since PV wire dimensions are not included in the NEC. PV wire may also be used in direct burial installations if it is listed and identified for direct burial.
NEMA members participate in the CANENA harmonization process, where there is a current effort to harmonize the product construction and testing standards for PV wire. Once completed, the draft standard will be processed by UL, the CSA Group, and the Mexican Association of Standardization and Certification (ANCE) for official recognition within the United States, Canada, and Mexico.
PV wire has to endure a variety of rugged installation conditions, such as extreme high and low temperatures, exposure to direct sunlight, direct burial, flexing when used with tracker modules, and wet locations. During the product certification process, PV wire is tested to verify that it can withstand expected conditions.
Currently, ANSI/UL 4703 Standard for Safety for Photovoltaic Wire is used to evaluate PV wire for use in the United States. PV wire can be marked up to 90°C in wet locations and up to 150°C in dry locations, with conductor voltage ratings of 600 V, 1000 V, or 2000 V.
Harmonizing the requirements for PV wire in North America will allow for greater efficiencies for manufacturers and increased choice for PV wire consumers.