Which item is described as a feature that can be automatically monitored by supervisory signals?

• A. Open and closing of water control valves
• B. Water tank level
• C. Power supplies for pumps
• D. Water pressure

Answer: (A)

Supervisory signals verify the position or status of a control device to ensure it’s in the correct condition and hasn’t shifted unintentionally. The open or closed state of a water control valve is a discrete position that can be monitored to confirm the valve is where it’s supposed to be for the system to operate safely. If the valve sticks, drifts from its set position, or is tampered with, a supervisory signal can alert the control panel to take appropriate action.

Water tank level and water pressure are sensor readings that indicate a condition in the system, but they don’t represent a controllable device’s position that needs constant verification in the way a valve does. Power supplies for pumps can be monitored for status, but the hallmark of a supervisory signal is confirming a valve’s position to guarantee the system’s control elements are in their intended state.