BS 7889:2012 pdf download
BS 7889:2012 pdf download.Electric cables -Thermosetting insulated,non-armoured cables with a voltage of 600/1 000 V, for fixed installations.
BS EN 60811-501. Electric and optical fibre cables — Test methods for non-metallic materials – Part 501: Mechanical tests – Tests for determining the mechanical properties of insulating and sheathing compounds
85 EN 60811-502, Electric and optical fibre cables — Test methods for non-metallic materials – Part 502: Mechanical tests – Shrinkage test for insulation
BS EN 62230, Electric cables — Spark-test method
IEC 60050-461, International Ele.ctrotechnical Vocabulary – Part 461: Electric 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 British Standard
NOTE See lila) for infoi’matsion on marking the cable with the cable manufacturer’s name and identifier.
3.2 length of lay
axial length of one complete turn of the helix formed by one cable component
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 specifications
3.5 type tests. T
tests made before supplying, on a general commercial basis, a type of cable covered by this British 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 materials, design or type of manufacturing process, which might change the performance characteristics.
3.6 values
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.
7.3 Clarity and durability
The colour used for core identification shall be clearly identifiable and durable such that it cannot be removed, when tested in accordance with 85 EN 50396.
5.1.
8 Laying up
The cores of cables having two, three, four or five cores shall be laid up with a right-hand or right-hand-left-hand alternating direction of lay. Cores shall be laid up in the sequence given in 7.1.
Conformity shall be checked by visual examination.
The maximum length of lay for core with circular conductors shall not exceed
65 times the diameter of the laid.up cores, and the maximum length of lay for
core with shaped conductors shall not exceed 80 times the diameter of the
Iaid.up cores.
Conformity shall be checked by the test method given in 15.4
If necessary the formation of a compact and reasonably circular cable shall be achieved by one of the following methods.
a) The application of synthetic fillers or binder tape(s).
b) The optional inner covering (see Clause 9).
C) The sheath (see Clause 10) provided it effectively fills the interstices.
d) Any combination of the above.
It shall be possible to strip the fillers and/or tape(s), if any, from the cable without damaging the insulation of the cores.
Conformity shall be checked visually.
9 Extruded optional inner covering
NOTE 1 The manufacturer has the option to inc?ude or not include an inner covering,
The optional inner covering, where used, shall consist of an extruded layer of synthetic polymeric material compatible with the operating temperature of the cable. It shall surround the single core and the laid-up two, three, four or five cores, giving the assembly a practically circular shape. The inner covering shall not adhere to the cores.
NOTE 2 For information, an appro.wimate value of thickness of the inner covering is given in Table 2 to Table 6.
It shall be possible to remove the inner covering without damaging the insulation of the core(s).
NOTE 3 The manufacturer may apply a tape or tapes over the optional extruded inner covering.
