What does a supervisory signal indicate?

A supervisory signal in a fire protection system indicates the need for action regarding system supervision. This type of signal alerts facility personnel to a condition that requires attention but does not necessarily indicate a fire or emergency situation. Such conditions may include issues like valve positions being closed that should be open, low pressure in the system, or other anomalies that could affect the system's performance or readiness.

Understanding that a supervisory signal prompts an investigation or corrective action highlights its role in maintaining the operational integrity of the standpipe system. It ensures that the system is always prepared for any fire emergency, which is crucial for safety. Other answers reflect different contexts, like operational status, water supply, or maintenance status, but they do not capture the specific purpose of supervisory signals in alerting staff to conditions that need supervision and oversight.