Under 2023 NEC 690.12, what is the safety purpose of the rapid shutdown function for a photovoltaic system on a building where that section applies?
- APreventing utility backfeed during an outage
- BProtecting modules against every lightning surge
- CMatching solar production to low utility demand
- Reducing the electric-shock hazard to firefighters
Where to look it up
https://docinfofiles.nfpa.org/files/AboutTheCodes/70/70_A2025_NEC_P04_FD_PIResponses.pdf
Why D is correct
The section identifies firefighter shock-hazard reduction as its purpose. It controls specified circuits and provides compliance alternatives; it does not declare the entire PV installation de-energized or safe to touch. In particular, inside-array compliance can use a listed or field-labeled PV hazard-control system, rather than a universal claim that every array conductor must be reduced to the same voltage. Source: 2023 baseline 690.12 and (B)(2), NFPA Public Input 4204, PDF pages 116–119 (printed 107–110). https://docinfofiles.nfpa.org/files/AboutTheCodes/70/70_A2025_NEC_P04_FD_PIResponses.pdf