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A fire alarm control panel Fire alarm speaker and pull station. Fire alarm systems are composed of several distinct parts: Fire alarm control panel (FACP), or fire alarm control unit (FACU): This component, the hub of the system, monitors inputs and system integrity, controls outputs, and transmits information.
The alarm transmission methods covered under UL 365 can be categorized under standard line security or encrypted line security. The systems are required to operate within the limits of Class 2 remote control and signal circuits as defined by the National Electrical Code, NFPA 70.
The NFPA 72 "covers the application, installation, location, performance, inspection, testing, and maintenance of fire alarm systems, supervising station alarm systems, public emergency alarm reporting systems, fire warning equipment and emergency communications systems (ECS), and their components."
First-generation wiring systems became susceptible to abuse by homeowners who would replace blown fuses with fuses rated for higher current. This overfusing of the circuits subjects wiring to higher levels of current and risks heat damage or fire. Knob-and-tube wiring may also be damaged by building renovations. [11]
Coded panels were the earliest type of central fire alarm control, and were made during the 1800s to the 1970s. A coded panel is similar in many ways to a modern conventional panel (described below), except each zone was connected to its own code wheel, which, depending on the way the panel was set up, would either do sets of four rounds of code until the initiating pull station was reset ...
An automotive wiring diagram, showing useful information such as crimp connection locations and wire colors. These details may not be so easily found on a more schematic drawing. A wiring diagram is a simplified conventional pictorial representation of an electrical circuit. It shows the components of the circuit as simplified shapes, and the ...
Many modern fire alarm pull stations are single-action and only require the user to pull down a handle to sound the alarm. Other fire alarm pull stations are dual-action, and as such require the user to perform a second task before pulling down, such as lifting or pushing in a panel on the station or breaking a glass panel with an attached hammer.
A circuit diagram (or: wiring diagram, electrical diagram, elementary diagram, electronic schematic) is a graphical representation of an electrical circuit. A pictorial circuit diagram uses simple images of components, while a schematic diagram shows the components and interconnections of the circuit using standardized symbolic representations.