Section 690.12/Rapid Shutdown of PV Systems
NEC 690.12 requires rapid shutdown capability for rooftop PV systems to protect firefighters from energized DC conductors.
PV system circuits on or in buildings must include a rapid shutdown function that reduces conductor voltage within the array boundary to 80 volts or less within 30 seconds of rapid shutdown initiation. The initiation device must be at a readily accessible location outside the array boundary. Conductors more than 3 feet from the array or more than 1 foot inside a building must also be limited to 80 volts within 30 seconds.
Why this section exists
PV arrays generate DC voltage whenever exposed to light. Firefighters responding to a building fire with rooftop solar panels face the risk of electrocution from energized DC conductors that cannot be de-energized by simply turning off the main breaker. Rapid shutdown provides a way to reduce the voltage on rooftop conductors to safe levels so firefighters can ventilate the roof and fight the fire without electrical hazards.
What plan reviewers look for
Plan reviewers check the PV system one-line diagram for rapid shutdown equipment (module-level power electronics or other listed rapid shutdown devices). They verify that the initiation device is located at a readily accessible exterior location and that the system is designed to reduce voltage within the array to 80 volts within 30 seconds. They also check that the rapid shutdown equipment is listed for the application.
Common violations
Related NEC requirements
Section 690.11 covers arc-fault circuit protection for PV systems. Section 690.31 covers PV system wiring methods. Section 690.41 covers system grounding. The 2023 NEC tightened the rapid shutdown requirements compared to earlier editions.