Fire alarm systems serve several important functions: notifying occupants of fire conditions, notifying first responders, signaling other onsite and offsite locations, signaling other building systems, and providing information to first responders. They are comprised of various components like control panels, power sources, initiating devices, and notification appliances. Initiating devices can be manual pull stations or automatic detectors like heat, smoke, and gas detectors. Notification appliances produce audible alarms through devices like horns, speakers, or bells and visible alarms through flashing lights or strobes. Different types of alarm signals include fire alarms, supervisory signals for other system issues, and trouble signals for problems in the system.

1. Fire Alarm System Components and Functions Chapter 7

20. Figure 7-9 Operational characteristics of automatic fire detectors

21. Figure 7-10 Line type heat detector

22. Figure 7-11 Applications of line type heat detection devices include conveyers and cable trays

23. Figure 7-15 Principle of operation – light scattering photoelectric smoke detector

24. Figure 7-16 Principle of operation – light obscuration photoelectric smoke detector