The maximum delay (retard) for a waterflow switch is?

The maximum delay (retard) for a waterflow switch is?

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

Answer: (C)

Waterflow switches include a built-in retard (delay) to prevent nuisance alarms from brief, non-fire flows. When water flow is detected, the switch starts a timer, and the alarm is generated only after that timer reaches the set duration, ensuring the flow is sustained. The maximum delay is ninety seconds, which balances filtering out short transients with keeping life-safety notification timely. A shorter delay (like thirty or sixty seconds) can still miss some false signals, while a longer delay (such as one hundred twenty seconds) would delay warning too much in a real fire.

Waterflow switches include a built-in retard (delay) to prevent nuisance alarms from brief, non-fire flows. When water flow is detected, the switch starts a timer, and the alarm is generated only after that timer reaches the set duration, ensuring the flow is sustained. The maximum delay is ninety seconds, which balances filtering out short transients with keeping life-safety notification timely. A shorter delay (like thirty or sixty seconds) can still miss some false signals, while a longer delay (such as one hundred twenty seconds) would delay warning too much in a real fire.