NFPA Journal

BY DEREK VIGSTOL

While the 2020 edition of NFPA 70®, National Electrical Code®, was published last fall, July tends to be when states shift to the latest edition. This delay between when the code was published and when it is actually implemented gives jurisdictions time to sort through what’s new and what’s changed, and to consider how the new edition of the code might affect them. Whether jurisdictions use the NEC as is, or whether they apply local amendments to the code, a thorough understanding of the revisions will help all users better comply with the ever-changing electrical landscape.

Two important areas that were subject to changes in the latest NEC were electric vehicles (EVs), as well as marinas and boatyards. Both of these topics have generated a great deal of activity in recent years, and the most recent changes reflect the efforts of both the code and the broader electrical community to remain as current as possible in how they address these rapidly evolving areas.

EVs have undergone—and continue to experience—a particularly rapid evolution over the past few years. From new battery chemistries that allow longer distances on a single charge, to using the battery in the vehicle to feed power back into a building, these technological advancements require the installation rules to adjust accordingly. The 2020 NEC includes a few revisions that users should be aware of when it comes to these systems.

Most notably, the code making panels of the NEC dealt with how to handle the EV supply equipment, or EVSE, that is bidirectional—equipment known in the industry as electric vehicle power export equipment, or EVPE. New systems are becoming available that can charge the vehicle under normal use and can also use the car to supply power to a building, such as a home or office, when the power is out, essentially turning these vehicles into energy storage equipment. New requirements in Article 625 cover things like GFCI protection for receptacles, supply cable requirements, and ratings for equipment.

Similarly, marinas, boatyards, and other facilities that utilize electricity on or near bodies of water have received a lot of attention recently from the electrical safety community. Unfortunately, this attention has resulted from multiple tragic events involving electric shock drownings (ESD). The evolution of the requirements around these areas has been taking place for a while, but for the 2020 NEC many of these requirements were adjusted.

One issue that was addressed was how the 2017 edition of the code required ground-fault protection that would trip at a maximum of 30mA total for the system. But docked vessels can “leak” current into the water, and situations arose where only a few vessels that were connected to electrical power in a marina could cause the protection to trip. This prompted marina owners to remove the ground-fault protection devices.

Referencing multiple studies on the topic of stray current entering the water, the code making panel looked at the amount of current that is likely to result in ESD—the panel determined that most vessels will have some amount of leakage current, but that most of those are low enough not to cause ESD. The panel further determined that shore power receptacles must be protected at the 30 mA level, while the feeder must be protected at a level not to exceed 100 mA. This adjustment will allow multiple vessels to be connected to shore power without tripping ground-fault protection devices, and will ideally eliminate any cause for marina owners to remove these life-saving devices.

There are many other changes to the 2020 NEC that could affect electrical installations in your jurisdiction. As the code is implemented in your region, understanding those changes, why they were made, and their potential impact will help you better apply the code’s requirements. The NEC exists to protect us from electrical hazards; proper installation is where it all starts, but the NEC can only achieve its goals when the requirements are applied as intended. 

Derek Vigstol is an NFPA technical lead, Electrical Tech Services.