This article provides a review of more significant changes to the rules for special equipment covered in Chapter 6, Special Equipment, of the 2017 National Electrical Code (NEC).
600.2 Definitions and 600.34 PV Powered Signs
Photovoltaic (PV) powered signs are now defined in 600.2 as a complete sign powered by solar energy consisting of all components and subassemblies for installation either as an off-grid, stand-alone; on-grid, interactive; or non-grid, interactive system. New Section 600.34 provides installation requirements for PV-powered signs.
Article 625 covers electric vehicle supply equipment (EVSE) and specifically addresses conductive charging and inductive (wireless) charging. Eight definitions are added to support new requirements for electric vehicle charging.
Multiple new definitions are added to address wireless power transfer. These definitions mirror terminology used in SAE J2954, a standard that covers wireless charging of electric and plug-in hybrid vehicles. A new Part IV of Article 625 provides rules for wireless power transfer equipment.
680.2 Electrically Powered Pool Lifts
An electrically powered pool lift is now defined in 680.2 as a lift that provides accessibility to and from a pool or spa for people with disabilities. New Article 680 Part VIII provides requirements for electrically powered pool lifts. Only the requirements in Part VIII of Article 680 apply to pool lifts. This equipment is required to be listed.
680.7 Grounding and Bonding Terminals
New Section 680.7, Grounding and Bonding Terminals, has been added and provides specific requirements for all grounding and bonding terminals. All must be identified for use in wet and corrosive environments and listed for direct burial use. Where field-installed in a damp, wet or corrosive environment, all must be composed of copper, copper alloy or stainless steel.
680.11 Location of Underground Pool Wiring
Requirements from 680.10 for location of underground wiring have been relocated to 680.11. The prohibition of wiring within 5 feet of the pool is removed; all permitted wiring methods are listed. Former Table 680.10 for minimum cover depths has been deleted. Now, all underground wiring cover depths in the pool area must be in accordance with Table 300.5.
690.12 Rapid Shutdown of PV Systems
Section 690.12 was significantly revised and separated into parent text and four first-level subdivisions. An array boundary is established with requirements for circuits outside and inside the array boundary. Three rapid-shutdown methods are provided for circuits inside the array boundary with an effective date of Jan. 1, 2019. The requirements for rapid shutdown of PV systems and equipment installed on buildings are in direct response to concerns expressed by first responders. Rapid shutdown provides responders with a method to reduce the output of PV systems to 30 volts within 30 seconds to allow for safe firefighting operations.
690.56(C) Marking Requirements for Buildings With PV Systems
Marking requirements for rapid shutdown were significantly revised to warn emergency responders of hazards presented by a PV system and associated conductors. Two specific types of markings now address the type of rapid shutdown of the PV system and conductors in 690.12. Two new figures provide prescriptive and consistent detail in the required markings.
691 Large-Scale PV Systems
Large-scale PV electric power production facilities are covered by new Article 691. The number of large-scale PV systems is relatively small, but they generate more power than the combined output of all residential and commercial PV. To qualify for applying Article 691, all provisions in 691.4 must be met.
A system is considered large-scale PV if it has a capacity of 5,000 kilowatts and is not under exclusive utility control. Only qualified personnel are permitted to maintain and operate these systems.
695.3 Power Sources for Electric-Driven Fire Pumps
A new informational note in 695.3 provides Code users with useful guidance for determination of reliability. NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection, has purview over fire pump performance and the reliability of the power source. Shutdowns, routine loss of power and overhead service conductors are identified as factors that would cause consideration that the source as unreliable.
Next month’s column will provide a close look at more important revisions in NEC chapters 7 and 8.