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RES Technical Corner by Kathleen Connolly (What is Article 691
Technical Corner
What is Article 691 – Large-Scale Photovoltaic (PV) Electric Power Production Facility?
As solar photovoltaic technology grows in popularity, we are seeing different scale projects pop up all across the country and world. Solar photovoltaic systems can vary significantly in power output and physical size. Many solar PV projects are small enough to fit on a residential roof and cover the electrical needs of the home, while others cover hundreds of acres of land and produce the same amount of power as a power plant. When Article 690 – Solar Photovoltaic (PV) Systems was created, it strove to cover the requirements specific to all solar PV projects, regardless of size. These different scale projects share many similarities, but also present some different challenges. As large-scale photovoltaic projects are gaining popularity, the industry has identified a need for additional codes that cover the technical requirements that are unique to these large-scale projects.
In order to do this, the 2017 NEC developed a new article, Article 691, to cover requirements that are applicable to large-scale PV projects. Article 691 – Large-Scale Photovoltaic Electric Power Production Systems covers the installation of projects that are 5000kW or greater. These projects still are held to the requirements of NEC 690, but have some additional requirements and exceptions that are spelled out in NEC 691. This article creates new definitions for equipment that typically is only found in these large-scale projects, such substations, transformers, and switchgear, and outlines the applicable technical requirements and restrictions. The new Article also outlines more stringent engineering and documentation that an AHJ can request, along with a new development, a fire mitigation plan, which outlines the operating procedure should a DC arc-fault occur.
As the industry progresses, it is expected that Article 690, along with the new Article 691 will continue to grow to address new concerns, challenges and industry wide practices.
Hopefully this article finds you well and can be used as a reference for your project needs. If anyone would like to contribute to the Rochester Engineer publication and add an article or would like to request information on a specific topic (not limited to electrical) just email me at beliasz@bergmannpc.com. As always, any comments are appreciated…! Thank you for reading.
Brett Eliasz, P.E., LEED AP BD+C , RES Director Kathleen Connolly, NABCEP Certified PV Installation Professional at Bergmann
Brett Eliasz, P.E., LEED AP BD+C , RES Director
Kathleen Connolly, NABCEP Certified PV Installation Professional at Bergmann
