What is the maximum retard for a waterflow switch in seconds?

What is the maximum retard for a waterflow switch in seconds?

• A. 30 seconds
• B. 60 seconds
• C. 90 seconds
• D. 120 seconds

Answer: (C)

Waterflow switches use a built-in delay, or retard, before signaling the fire alarm after water flow is detected. This pause helps weed out false alarms from brief or incidental flows, like testing, minor leaks, or transient flows in the pipe. The maximum retard time is the longest allowed delay for the system to still promptly alert on a real fire while still avoiding nuisance alarms. In this context, 90 seconds is the upper limit that provides a practical balance: long enough to verify sustained flow, but short enough to ensure a fire is detected in a timely manner. Shorter delays (such as 30 or 60 seconds) may reduce nuisance alarms but offer less protection against false triggers, while a longer delay (like 120 seconds) could delay life-safety notification too much. Hence, 90 seconds is the correct maximum.

Waterflow switches use a built-in delay, or retard, before signaling the fire alarm after water flow is detected. This pause helps weed out false alarms from brief or incidental flows, like testing, minor leaks, or transient flows in the pipe. The maximum retard time is the longest allowed delay for the system to still promptly alert on a real fire while still avoiding nuisance alarms. In this context, 90 seconds is the upper limit that provides a practical balance: long enough to verify sustained flow, but short enough to ensure a fire is detected in a timely manner. Shorter delays (such as 30 or 60 seconds) may reduce nuisance alarms but offer less protection against false triggers, while a longer delay (like 120 seconds) could delay life-safety notification too much. Hence, 90 seconds is the correct maximum.