This British Standard specifies requirements and test methods for the construction and performance of cables which:
have thermosetting insulation and a rated voltage of300/500V;
provide resistance to fire (circuit integrity), including with mechanical shock and with water, as measured by performance in a standard test or tests;
emit limited amounts of smoke and corrosive gases when burned as measured by a standard test; and
are primarily intended for use in emergency lighting, fire detection and fire alarm system circuits.
The circuit integrity performance under fire conditions is assessed on the basis of tests which measure resistance to fire with mechanical impact and water spray (Categories: Standard30, Standard60and Enhanced120).
NOTE1 BS5266‑1and BS5839‑1give recommendations and guidance on the factors to be taken into account in the planning, design, installation, commissioning and maintenance of emergency lighting, fire detection and fire alarm systems for buildings, respectively.
It is applicable to2‑core,3‑core and4‑core circular cables with an uninsulated full-size circuit protective conductor (CPC), and7‑core,12‑core and19‑core circular multicore auxiliary cables with an uninsulated drain wire of not less than 0.5mm2. All cables contain a metallic layer, which provides electrostatic screening.
The cables are suitable for operation at a maximum sustained conductor temperature of70°C and for a maximum short‑circuit conductor temperature of250°C (for a maximum period of5s).
NOTE2 AnnexA gives recommendations for the selection, installation and operation of cables, AnnexB gives the method of test for continuity of tinned coating of wires, AnnexC gives the method of test for voltage withstand, AnnexD gives the method of test for bending characteristics, AnnexE gives the method of test for resistance to impact, AnnexF gives the method of test for shrinkage of sheath and AnnexG gives notes on type tests.