CHOOSING A CATEGORY
Choosing the category of system is the very first decision that has to be made before a fire detection design or installation can take place.
The various system categories are to be regarded as a “menu”, from which one can select a suitable system for any building.
Because of the wide range of systems covered in SANS 10139, the specification of requirements for a system, without a reference to a system category, has little meaning.
The category of system to be installed always needs to be included in the specification.
The specification of any category of system, other than Category L1, M or P1, always needs to include details of those areas of the building that are to be protected.
Category L1, L2, L3 and L4 systems should also satisfy the recommendations of SANS 10139 for a Category M system.
The category of system may be stipulated in the requirements imposed by an enforcing authority, by property insurers or by the purchaser of the system, that category should be used.
If the designer has not been informed as to the category of system required, he/she should make the decision on the category in consultation with the end user and /or the fire consultant. It is important that the end user can confirm that the category of system will be compatible with any fire strategy for the premises.
The contractor should never try to fit a system category to meet their installation at the end of the job.
The system category dictates where devices should be installed and the basis for design, installation and inspection.
NOTE: Annex A of SANS 10139 provides information on the categories of systems that are typically installed in various types of premises.