BS/EN 2812-2019 pdf download.Aerospace series – Stripping of electric cables.
— damaging the core strands or the insulator when stripping a single conductor wire;
— damaging the screen or the inner wire(s) when stripping a shielded cable or coaxial cable.
The stripping operation must not reduce the original performances of the wire or cable as defined in its technical specification.
The stripping length depends on the length required to connect the conductor into the end component. Each process must be applied by trained operators.
For qualification to a wire and cable standard, there must be an agreement between the wire and cable manufacturer and the qualifying authority on exact tool reference to use. The exact reference of this tool must be written In the associated test report.
6.2 Method
Qualification of a dedicated tool to strip a wire or cable type will be performed by stripping of samples coming from at least two (2) different batches (ideally for manual stripping pliers used for single wires, batches shall have conductors not coming from the same conductor batch, and if possible one at the maximum conductor diameter and the other at the minimum).
The qualification method of stripping a single conductor wire is the following:
— The inspection of stripped cable ends, for which the tool will be used, shall be carried out on 10 samples coming from the same manufacturing batch for each wire size. Five (5) samples will have one strip at each extremity and the other five (5) samples a double strip at each extremity.
— The first strip shall be made approximately 10 mm from the end of the wire and the second strip approximately 20 mm from the end of the wire. All slugs of Insulation shall be cut cleanly, with no residual insulation remaining on the conductor (see Figure A.6). Using a 10 times magnification aid, the conductor of the wire shall be examined for damage, at the position of the first strip.
The qualification method of stripping a shielded cable or coaxial cable is the following:
— The inspection of stripped cable ends, for which the tool will be used, shall be carried out on 10 samples coming from the same manufacturing batch for each cable size. Five (5) samples will have one strip at each extremity and the other live (5) samples will have six (6) strIp cuts at each extremity.
— The first strip shall be made approximately 10 mm from end of the cable, the second strip approximately 20 mm, the third strip at approximately 30 mm, etc. All slugs of insulation shall be cut cleanly, with no residual insulation remaining on the screen (see Figure A.16). Using a 10 times magnification aid, both screen and inner wire(s) (inner insulator in the case of coaxial cable) of the cable shall be examined for damage, at the position of the different strips.
6.3.2 Mechanical stripping
The geometrical configuration of the blade assembly shall allow automatic centring of the cables without damaging or cutting the strands.
l)uring the stripping, the cable shall be maintained at 900 in relation to the blade and the separation o’ the Insulation shall be made parallel to the cable.
Each blade profile shall be calibrated in relation to the dimensions of the cable, as shown in Annex B (informative) (Figure BA).
For stripping with power tools, the rotating of the blade(s) shall be in the same plane and form a cutting circumference whose diameter is greater than the maximum diameter of the conductor of the cable to be stripped.
After stripping, the conductor shall show no damage to or untwisting of the strands according to Annex A (normative). Taking into account expansion of conductor cross-sections larger than 2 mm2, some marks on the strands are permissible (see Figure A.4), however the material of the conductor beneath the plating shall not be visible.
Th insulation remaining on nw wire or raMe shall chow no damage due In the tooling, however light marks may be tolerated (see Figure A.9).
6.3.3 Laser stripping
During laser stripping the position of the laser focus in relation to the surface of the wire insulation or cable jacket shall be maintained within the necessary tolerance to ensure that the stripping process meets the quality requirements of this standard.
After stripping the insulation or jacket can be removed by hand or other mechanical means; removal shall be made parallel to the cable.
After stripping, the wire conductor shall show no damage to or untwisting of the strands according to Annex A (normative), see IableA.I.
The cable screen and inner wire(s) (Inner insulator In the case of a coaxial cable) shall show no damage according to AnnexA (normative). see Table A.2.
The insulation remaining on the wire or cable shall show no damage due to the process (see particularly Figure A.3 and A.13). However a heat affected zone adjacent to the strip point may be present, caused by the heating effect of the laser on the Insulation, and this Is acceptable. The heat affected zone shall be in accordance with Ann,A (normative), particularly Figure A.1 I and Figure A.20. The heat affected zone shall be s 1 mm in length; within the heat affected zone a degree of discoloration and/or melting of the Insulation may be visible to the naked eye. Discolouration of the insulation may be particularly noticeable with pure polyimide or polyimide composite constructions.BS/EN 2812-2019 pdf download.