According to NFPA 72, at what position can the off-normal signal of a tamper switch control valve be restored?

The correct answer is that the off-normal signal of a tamper switch control valve can only be restored to the normal position. This is based on NFPA 72 standards, which focus on ensuring that fire alarm systems function reliably and provide accurate information about the status of various components.

A tamper switch is designed to indicate whether a valve is in the correct position for proper operation. Restoring the off-normal signal to the normal position indicates that the tamper switch has returned to a state that signifies it is properly engaged and that the valve is in the appropriate position for the system to function as intended. This is essential for system integrity and for ensuring that fire protection measures are in place when needed.

Restoring the signal to any other position, such as off, emergency, or any unspecified position, would not align with NFPA 72's requirements for clear and accurate indicator signals. Such positions could lead to confusion about the status of the system and potentially compromise safety. Therefore, the normal position is required to confirm that the valve and its corresponding switch are operating correctly within the established guidelines.