TL;DR
Rapid shutdown is the NEC-mandated capability of a rooftop solar system to drop conductor voltages to safe levels within seconds of activating a switch, protecting firefighters who must cut into a roof. Since the 2017 code cycle, conductors inside the array boundary must fall to 80 volts or less within 30 seconds, which in practice requires module-level electronics—microinverters, optimizers, or dedicated devices.
What it means
Rapid shutdown is the NEC-mandated capability of a rooftop solar system to drop conductor voltages to safe levels within seconds of activating a switch, protecting firefighters who must cut into a roof. Since the 2017 code cycle, conductors inside the array boundary must fall to 80 volts or less within 30 seconds, which in practice requires module-level electronics—microinverters, optimizers, or dedicated devices. An exterior initiation switch and labeling tell first responders where to act.
Where it sits in the glossary
Rapid shutdown is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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