What must a solar PV system's rapid shutdown function accomplish within the array boundary, and how fast?
Not quite. The answer is B: Reduce voltage within the array boundary to 80 V or less within 30 seconds of initiation
690.12 requires PV rapid shutdown to bring conductors within the array boundary down to 80 V or less within 30 seconds of activation, protecting firefighters and first responders working near or on a roof with live PV conductors. Getting the voltage and time figures reversed is an easy way to miss this question.
Reference: NEC 2023 690.12 (Solar PV Rapid Shutdown)
Checked against multiple published sources
An IAEI article on the 2023 NEC states 80 V within 30 seconds inside the array boundary under 690.12(B)(2); an ExpertCE article states the same limit and notes it carried through the 2020 and 2023 editions. Neither is the code text. The 2023 NEC also changed how the section is organized, so subsection letters differ from older editions.
Trade Code Wizard is not affiliated with, endorsed by, or licensed by the International Code Council (ICC), the National Fire Protection Association (NFPA), IAPMO, the ESCO Institute, NATE, HVAC Excellence, NASCLA, NICET, the U.S. Environmental Protection Agency, PSI, Prov, Pearson VUE, or any state or local licensing board. Exam and code names are used only to identify which examination this study material prepares you for.
These are original practice questions written to publicly published exam content outlines. They are not actual exam questions, and they do not reproduce code text. Explanations cite code sections and state requirements in our own words — always verify against the code edition your jurisdiction has adopted, which may differ from the edition cited here.
Passing is not guaranteed. This is study material, not a substitute for the adopted code, for your licensing board's requirements, or for qualified instruction.