Which statements are true about the disconnect switch?

• A. It interrupts the releasing circuit to the suppression system
• B. It causes a supervisory signal at the releasing control unit
• C. It must be located inside a lockable control panel, inside a lockable enclosure, or require a key for activation
• D. All of the above

Answer: (D)

The disconnect switch for a clean agent releasing system is designed to do three important things to keep the system safe and controllable. First, it interrupts the releasing circuit, so opening the switch stops the current path that would trigger the agent release, preventing accidental or unauthorized discharge during maintenance or faults. Second, its status is communicated to the releasing control unit as a supervisory signal, so the control system always knows whether the releasing circuit is open or closed and can detect faults or tampering. Third, to prevent unauthorized activation, the switch must be housed in a lockable control panel or enclosure or require a key for activation, ensuring only authorized personnel can operate it. Taken together, these requirements cover safety, control, and security, so all the statements are true.