To avoid unwanted discharge of an electrically clean agent system, what shall be provided?

• A. A supervised disconnect switch
• B. A remote alarm signal
• C. An automatic discharge valve
• D. A manual bypass switch

Answer: (A)

The key idea is having a controlled, monitored way to cut power to the system so it cannot discharge by accident. A supervised disconnect switch provides a solid electrical break in the control circuit and, crucially, is watched by a supervision circuit that confirms the switch is in the correct position. If power is cut or the switch moves to isolate the system, discharge cannot occur because the control power is effectively removed, and any fault or restoration condition triggers a visible alarm. This combination of isolation and continuous status supervision is what prevents unwanted release of the clean agent.

A remote alarm signal simply tells you the status but doesn't prevent discharge. An automatic discharge valve would cause discharge on its own, which is the opposite of what’s needed. A manual bypass switch could be operated to circumvent safeguards, increasing the risk of unintended discharge.