2023 Electrical Safety Code – Safety Rules for Solar Farms

The National Electrical Safety Code (NESC®), also referred to as IEEE-C2, covers the practical safeguarding of utility persons during the installation, operation or maintenance of electric supply stations, overhead supply lines, and underground or buried supply cables.

The NESC® is a recognized American National Standard and has been adopted in whole or part by most U.S. states. The NESC® is updated every five years to keep the Code current with changes in the industry and technology. The new Code took effect on February 1, 2023.

The revised NESC® includes a new Section (19) to address photovoltaic (PV) generating stations, commonly referred to as solar farms. The provisions of the section apply to PV generating stations that are under the exclusive control of utilities and are not mounted on occupied buildings. There are five components within this section: location, grounding configurations, vegetation management, DC overcurrent protection, and DC conductors.

New requirements of NESC® include:   

• Access to PV generating stations shall be restricted to authorized personnel only. This must be accomplished by either fencing or other adequate means of controlled access in accordance with Rule 110 which is the general requirement in electric supply stations.
• Vegetation management should be performed around supply lines as experience has shown this to be necessary. Vegetation that may damage conductors should be pruned or removed. For additional information, refer to the Loss Control white paper on Wildland Fire Hazard Risk Reduction for Solar PV Sites, located on AEGISlink.com, listed under Publications.  
• With respect to DC overcurrent protection, cables designed for continuous short-circuit current conditions are not required to meet Rule 161C, which pertains to insulated power cables.
• Ungrounded and functional grounded PV DC conductors shall be insulated unless otherwise guarded. Additionally, cables secured to racking or tracking structures shall be protected from physical damage.
• For DC system grounding, PV array DC circuits shall be permitted to be ungrounded or to employ functional grounded PV DC conductors. Protective grounds within the DC system shall comply with Rules 123A through 123C, which address protective grounding. 
• For AC system grounding, AC circuits in a PV generating station shall be grounded in accordance with the methods specified in Section 9, which addresses grounding methods for electric supply and communication facilities.   

For more information, please contact Loss Control Utility Operations Vice President, Laura Strowbridge, P.E., by e-mail or 201.289.0787, or your designated AEGIS Loss Control Senior Electric Utility Professional.

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