BS5839-1 Cable

All cables are designed to ensure that the interconnections between fire alarm systems operate correctly for an appropriate length of time in the event of an evacuation. However the BS5389 cable standard refers to ‘Standard’ and to ‘Enhanced’ grade cables, which determines the level of fire resistance that the cables offer. The ‘Enhanced’ grade  are designed for use where the fire detection and fire alarm systems need to support evacuation for a greater duration than that offered by the general use ‘Standard’ grade fire proof cables during a fire situation.

In addition to complying with the specification set out in BS5839-1, when tested in accordance with EN 50200, Standard fire performance cables must achieve a class of at least PH30. They must also maintain circuit integrity for at least 30 minutes when exposed to a sequence of flame, mechanical shock and water spray. The requirement for Enhanced fire resistant cables is 120 minutes.

Enhanced fire resistant cables are also recommended for the following applications:

in unsprinklered buildings (or areas) in which the fire strategy involves evacuation of occupants in four or more phases

In unsprinklered buildings of greater than 30m in height

In unsprinklered premises and sites in which a fire in one area could affect cables of critical signal path associated with areas remote from fire, in which it is envisaged people will remain in occupation during the course of the fire

In any setting where, on the basis of a fire risk assessment, the designer, specifier or regulatory authority considers that use of Enhanced fire resisting cables is required.

The different parts of this Standard cover the variations in practice for domestic and non-domestic usage as well as other applications and should be referred to directly when commissioning and designing any project.

Other Standards referred to within BS5839-1

BS5389 cable products