BS 7846:2015

This standard BS 7846:2015 Electric cables. Thermosetting insulated, armoured, fire-resistant cables of rated voltage 600/1 000 V for fixed installations, having low emission of smoke and corrosive gases when affected by fire. Specification is classified in these ICS categories:

• 13.220.99 Other standards related to protection against fire
• 29.060.20 Cables

This British Standard specifies requirements for construction and performance of thermosetting insulated, armoured, fire-resistant cables of rated voltage 600/1 000 V having low emission of smoke and corrosive gases when affected by fire.

This British Standard is applicable to cables for use in fixed installations in industrial areas, buildings or similar applications, where maintenance of power supply during a fire is required for a defined period of time.

This British Standard specifies requirements for the following types of cables:

1. wire armoured and oversheathed cables with two-, three-, four- or five-cores, and with stranded copper conductor;

2. multicore auxiliary cables, wire armoured and oversheathed, with stranded copper conductor.

This British Standard specifies four categories of cables based on their performance in tests which assess separately resistance to fire, resistance to fire with water spray and resistance to fire with mechanical shock (Category F2) and which assess resistance to fire with direct mechanical impact and water jet in combination (Categories F30, F60 and F120).

This British Standard is applicable to cables that are designed for a maximum sustained conductor temperature of 90 °C and for a maximum short-circuit conductor temperature of 250 °C (for a maximum of 5 s).

NOTE 1 Limitation on the temperature of the cables might be imposed in situations where they may be touched or where they could touch other materials.

NOTE 2 Annex A gives the guide to use, Annex B gives armour wire tests, Annex C gives compatibility test, Annex D gives abrasion test, Annex E gives insulation resistance constant test on oversheath, Annex F gives resistance of conductor and armour, Annex G gives gross cross-sectional area of armour, Annex H gives a test for shrinkage of oversheath, Annex I gives the fire resistance test for category F2 – additional provisions for cables with a diameter over 20 mm, and Annex J gives notes on type tests.