Which component provides power and battery backup in a fire alarm system?

• A. Notification appliances
• B. Initiating devices
• C. Fire alarm control panel
• D. Power supply with battery backup

Answer: (D)

The main idea here is that the system needs a reliable power source plus a built-in backup so it can keep operating when the main power drops. The power supply with battery backup provides the necessary operating power for all components and stores energy in batteries to keep the entire fire alarm system running during a power outage. It powers everything from detectors and control logic to the audible/visual alerts, ensuring continuous operation until power is restored or the batteries are replaced. The fire alarm control panel, while it acts as the brains of the system and coordinates actions, relies on this power source rather than providing the power itself. Initiating devices (sensors and manual pull stations) trigger the system but do not supply power, and the notification appliances (horns, strobes) deliver the alert but depend on the power supplied by the backup-capable power supply.