Manual fire alarm call point is a device for the manual operation of an electrical fire alarm system
Manual fire alarm boxes should be installed at unobstructed, readily accessible locations throughout the protected area with at least one box on each floor. Travel distance to a box should not exceed 200 ft. from any point in the area. The operable part of each manual fire alarm box shall be not less than 42 in. (1.07 m) and not more than 48 in. (1.22 m) above floor level and, the box location should be positioned in the normal path of exit from the area. The mounting surface shall be of a contrasting color.
Types of Manual Fire Alarm Boxes (Stations)
- (a) Contains a normally open or closed switch that is housed within a distinctive enclosure. Once actuated, the box must be reset to restore the unit to normal.
- (b) Contact and circuit arrangements may very to provide a number of functions simultaneously.
- (a) Contains a mechanically or electri-cally driven motor, or an electronic pulse generator. When activated, the motor turns a code wheel causing contacts to momentarily open or close or the pulse generator operates to reproduce the code of the box. The box is required to repeat its code a minimum of three times.
- (b) Contact and circuit arrangements many very to provide a number of functions simultaneously.
- To initiate an alarm, one must first break glass or some other element. The purpose is to identify which box was operated and to discourage tampering with the box when there is no fire to report.
- A manual fire alarm box that does not have a breakglass feature.
- Single Action
- A single action of breaking a glass or other frangible element or pulling a leaver or other movable part initiates an alarm.
- Double Action
- Two actions are necessary to initiate an alarm. Either break a glass to open a door or lift a cover to gain access to a switch or lever to initiate an alarm.