Please review fire alarm training manual pdf following URL and make sure that it is spelled correctly. This article may contain an excessive amount of intricate detail that may only interest a specific audience. Potomac Hall, at James Madison University. The examples and perspective in this article may not represent a worldwide view of the subject.
Coded panels were the earliest type of central fire alarm control, and were made during the 1800s to the 1970s. A Fire-Lite Sensiscan 1000 fire alarm control panel in a building at Oklahoma State University. Conventional panels have been around ever since electronics became small enough to make them viable. Conventional panels are used less frequently in large buildings than in the past, but are not uncommon on smaller projects such as small schools, stores, restaurants, and apartments.
A conventional fire alarm control panel employs one or more circuits, connected to initiating devices wired in parallel. These sensors are devised to dramatically decrease the circuit resistance when the environmental influence on any sensor exceeds a predetermined threshold. To facilitate location and control of fire within a building, the structure is subdivided into definite areas or zones. Floors of a multistory building are one type of zone boundary. Larger systems and increasing demand for finer diagnostic detail beyond broad area location and control functions expanded the control by zone strategy of conventional systems by providing multiple initiating circuits within a common zone, each exclusively connected to a particular type of initiating device, or group of devices. Even larger systems and demands for finer diagnostic and location detail led to the introduction of addressable fire alarm systems, with each addressable device providing specific information about its state while sharing a common communication circuit. Annunciation and location strategies for the most part remain relatively unchanged.
Multiplex systems, a sort of transition between conventional and modern addressable systems, were often used in large buildings and complexes from the mid to late 1970s into the late 1980s. Early on, these systems were programmed to function as large conventional systems. Gradually, later installations began to feature components and features of modern addressable systems. Releasing panels are capable of using solenoids to disperse fire-fighting chemical agents such as halon or water from piping located throughout a building. A releasing panel usually will have a manual abort switch to abort an accidental release which could damage property or equipment.
Releasing capability can be part of both addressable or conventional panels. A Simplex 4100U InfoALARM addressable fire alarm control panel: note the voice-evacuation microphone built into it. Addressable panels are usually more advanced than their conventional counterparts, with greater information capacity and control flexibility. Addressable fire alarm panels were introduced by many manufacturers during the microcontroller boom in the mid 1980s. Addressable Fire Alarm Control Panel employ one or more Signaling Line Circuits – usually referred to as loops or SLC loops – ranging between one and thirty.