BS 8436:2011 pdf download – Electric cables – Specification for 300/500 V screened electric cables having low emission of smoke and corrosive gases when affected by fire, for use in walls, partitions and building voids – Multicore cables
3 Terms and definitions For the purposes of this British Standard the terms and definitions given in IEC 60050-461 and the following apply.
3.1 cable manufacturer organization that has the capability to both produce and control the conformity of cable made to this standard NOTE See Clause 11.1, a) for information on marking the cable with the cable manufacturer’s name and identifier.
3.2 let-through energy, I 2 t energy let-through value of a device, measured in amperes squared seconds (A 2 s)
3.3 routine tests, R tests made on all production cable lengths to demonstrate their integrity
3.4 sample tests, S tests made on samples of completed cable, or components taken from a completed cable, adequate to verify that the product meets the design requirements
3.5 type tests, T tests made before supplying, on a general commercial basis, a type of cable covered by this standard, in order to demonstrate satisfactory performance characteristics to meet the intended application NOTE These tests are of such a nature that after they have been made, they need not be repeated unless changes are made in the cable material, design or type of manufacturing process, which might change the performance characteristics.
3.6.1 approximate value value which is only indicative NOTE Values described as “approximate” do not constitute requirements to be checked by measurement.
3.6.2 nominal value value by which a quantity is designated NOTE Nominal values usually give rise to values to be checked by measurements taking into account specified tolerances.
3.7.1 maximum voltage, U m maximum sustained power-frequency voltage between phase conductors for which the cable is suitable
3.7.2 rated voltage, U nominal power-frequency voltage between phase conductors for which the cable is suitable
3.7.3 rated voltage, U o nominal power-frequency voltage between conductor(s) and earth for which the cable is suitable
4 Voltage designation
The cables shall be designated by the rated voltages U o and U, expressed in the form U o /U. The rated voltage recognized for the purpose of this British Standard shall be 300/500 V.
5 Conductors The conductors shall conform to BS EN 60228, class 1, 2 or 5. The insulated conductors shall be plain or tinned annealed copper. The uninsulated circuit protective conductors shall be tinned annealed copper and shall be of the same nominal cross-sectional area as the insulated conductors. Tinned coated wires shall conform to BS EN 13603:2002, Clause 5. The class of conductor shall be the same for all conductors in any single cable. The uninsulated circuit protective conductor shall be of the same class as the insulated conductors.
6.1 Type The insulation shall be one of the following types:
• EI 5, as specified in BS EN 50363-5;
• GP 4 or GP 6, as specified in BS 7655-1.2;
• GP 8, as specified in BS 7655-1.3.
NOTE 1 BS EN 50363-5 specifies various requirements for assessing the insulation’s corrosive and acid gas emission. To conform to this British Standard, it is only necessary to assess corrosive and acid gas emission in accordance with 6.5, regardless of insulation types.
NOTE 2 A tape or tapes can be applied over either the conductor or the insulation.
6.2 Application The insulation shall be applied closely to the conductor or conductor taping by the extrusion process and cross-linked to form a compact and homogeneous layer.
NOTE 1 The insulation can be applied in a single layer or in a number of cohesive layers. Where more than one layer is used, all testing specified in this British Standard shall be carried out on the complete insulation as though it were a single layer of the declared insulation type (see 6.1).
NOTE 2 Insulation applied in more than one layer does not conform to the definition of “double insulation” given, for instance, in BS 7671. When the application is tested by removing the insulation from the conductor, there shall be no damage to the insulation itself, the conductor or the tin coating (if any).