What is the typical role of the automatic transfer switch in NFPA 20?

What is the typical role of the automatic transfer switch in NFPA 20?

• A. To switch power source from normal to emergency
• B. To regulate pump speed
• C. To monitor suction pressure
• D. To shut down the system

Answer: (A)

The automatic transfer switch is responsible for ensuring the fire pump stays powered by moving its supply from the normal utility source to an emergency standby source when normal power fails. NFPA 20 requires a reliable means to keep the pump energized during an outage, and the ATS handles that transition automatically, usually in response to a loss or degradation of the normal power. It also isolates the normal source to prevent backfeeding and coordinates with the pump controller so the emergency source is ready and the pump can start and run on emergency power. This role is about switching power sources, not regulating pump speed, monitoring suction pressure, or shutting the system down.

The automatic transfer switch is responsible for ensuring the fire pump stays powered by moving its supply from the normal utility source to an emergency standby source when normal power fails. NFPA 20 requires a reliable means to keep the pump energized during an outage, and the ATS handles that transition automatically, usually in response to a loss or degradation of the normal power. It also isolates the normal source to prevent backfeeding and coordinates with the pump controller so the emergency source is ready and the pump can start and run on emergency power. This role is about switching power sources, not regulating pump speed, monitoring suction pressure, or shutting the system down.