In a fire alarm system, which device receives the initiation signal and triggers the alarm sequence?

In a fire alarm system, which device receives the initiation signal and triggers the alarm sequence?

• A. Fire alarm control unit
• B. Alarm notification device
• C. Alarm initiation device
• D. Power supply

Answer: (C)

The Fire Alarm Control Unit is the device that receives the initiation signal and triggers the alarm sequence. It acts as the system’s brain, collecting signals from all initiating devices such as smoke or heat detectors and manual pull stations. When the control unit gets an initiation signal, it processes and validates it, then energizes the appropriate output circuits to activate the alarm notification devices (sirens, horns, strobes) and often initiate other actions programmed into the system, like door release or elevator recall. The initiation device is simply the source that detects or activates the alarm and sends that signal to the control unit, not the component that starts the alarm sequence by itself. The power supply simply provides power to the whole system; it doesn’t initiate or trigger the alarm.

The Fire Alarm Control Unit is the device that receives the initiation signal and triggers the alarm sequence. It acts as the system’s brain, collecting signals from all initiating devices such as smoke or heat detectors and manual pull stations. When the control unit gets an initiation signal, it processes and validates it, then energizes the appropriate output circuits to activate the alarm notification devices (sirens, horns, strobes) and often initiate other actions programmed into the system, like door release or elevator recall. The initiation device is simply the source that detects or activates the alarm and sends that signal to the control unit, not the component that starts the alarm sequence by itself. The power supply simply provides power to the whole system; it doesn’t initiate or trigger the alarm.