When water flow is detected that equals or exceeds the flow of a single sprinkler, how soon must the alarm signal be initiated?

The requirement for initiating an alarm signal upon detecting water flow that equals or exceeds the flow of a single sprinkler is vital for effective fire protection and safety. According to NFPA 72, when such water flow is detected in a system, it is imperative to start the alarm signal within 90 seconds. This time frame allows for rapid notification to alert occupants of a potential fire hazard while also providing emergency services with an early warning to respond appropriately.

The rationale behind this 90-second requirement is grounded in the need to ensure timely communication during a fire incident. By triggering the alarm within this period, the system can help facilitate a quicker response to a potential fire, which can be critical in minimizing damage and ensuring safety. It's essential that systems adhere to these time-sensitive protocols for optimal performance and adherence to safety standards outlined in the NFPA guidelines.