Is a software-based disconnect acceptable as a substitute for a physical disconnect switch?

• A. Yes
• B. No
• C. Only for small rooms
• D. Only with AHJ approval

Answer: (B)

A physical disconnect is required because it provides an immediate, independent means to isolate the release system, not reliant on electronics or software. In an emergency, you need a clearly visible, manually operable switch that can de-energize or stop the release without depending on power, networks, or computer logic. A software-based disconnect introduces risk from power failures, software glitches, or tampering, which could delay or prevent safe isolation. NFPA 2001 expects a hardware-level disconnect accessible to responders, ensuring reliable isolation when needed. AHJ approval does not replace this requirement, since a software-only solution does not meet the intent of providing a hard, fail-safe means of isolation.