Fire Detection, Fire Source Identification, Zoning

To ensure a fast and unambiguous identification of the fire source, the protected areas should be divided into zones. When determining the area to be covered by a zone, consideration should be given to accessibility, size, the fire routine determined for the premises and particularly in occupied premises, that each zone is accessible from the main circulation routes leading from where the control panel is sited.

In general the following guidelines for the size of the zone should be observed:

• If the total area of the building (i.e. the total of the floor areas of each floor) is not greater than 300m², then the building need only be one zone, no matter how many
  floors it has.
• The total floor area of a zone should not exceed 2000m².
• The search distance should not exceed 30m. The use of remote indicator lamps
  outside doors may reduce the number of zones required.
• If the zone covers more than one fire compartment, then the zone boundaries
  should follow compartment boundaries.
• If the building is split into several occupancies, no zone should be split between
  two occupancies.

A fault or faults in one zone must not prevent the operation of other zones. In a conventionally zoned system this presents no problem as the zones are wired on separate circuits. A single fault should not remove protection from an area greater than that allowed for a single zone.

Power Supply

Connection to the mains supply should be via a switch-fuse reserved solely for the purpose, it's cover being painted red and labeled "FIRE ALARM: DO NOT SWITCH OFF".