Conventional Fire Alarm Control Panels
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 sensors (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. In a conventional fire alarm system, the information density is limited to the number of such circuits used.
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.
An Initiating Device Circuit connected to multiple devices within the same "zone" of protection, effectively provides 2 bits of information about the zone corollary to the state of the circuit; normal, or off normal and alarm or quiescent. The state of each Initiating Device Circuit within a zone displays at the Fire Alarm Control Panel using visible indications called Annunciators.
These Annunciators may employ a graphical representation of the Zone boundaries on a floor plan (Zone map) using textual descriptions, illuminated icons, illuminated sections, or illuminated points on the map corresponding to Initiating Circuits connected to the Fire Alarm Control Panel.
For this reason, slang often inaccurately refers to initiating circuits of a Fire Alarm Control Panel as Zones.
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. This arrangement forms a device type by Zone matrix whose information is particularly suited to the Tabular Annunciator In multistory buildings employing a Tabular Annunciator for Example; rows of indicators define the floors horizontally in their stacked relationship and the type of device installed on that floor displays as columns of indicators vertically aligned through each floor. The intersection of the floor and device indicators provides the combined information. The density of information however remains a function of the number of circuits employed.
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.
Read more about this topic: Fire Alarm Control Panel
Famous quotes containing the words conventional, fire, alarm, control and/or panels:
“People always blame the girl; she should have said no. A monosyllable, but conventional wisdom has always been that boys can’t manage it.”
—Anna Quindlen (b. 1952)
“In England if something goes wrong—say, if one finds a skunk in the garden—he writes to the family solicitor, who proceeds to take the proper measures; whereas in America, you telephone the fire department. Each satisfies a characteristic need; in the English, love of order and legalistic procedure; and here in America, what you like is something vivid, and red, and swift.”
—Alfred North Whitehead (1861–1947)
“Dignity takes alarm at the unexpected sound of laughter.”
—Mason Cooley (b. 1927)
“America is not so much a nightmare as a non-dream. The American non-dream is precisely a move to wipe the dream out of existence. The dream is a spontaneous happening and therefore dangerous to a control system set up by the non-dreamers.”
—William Burroughs (b. 1914)
“He sent for lancewood to make the thills;
The crossbars were ash, from the straightest trees;
The panels of white-wood, that cuts like cheese,
But lasts like iron for things like these;
The hubs of logs from the “Settler’s ellum,”—
Last of its timber,—they couldn’t sell ‘em,”
—Oliver Wendell Holmes, Sr. (1809–1894)