IEC 60811-504-2012 pdf free download
IEC 60811-504-2012 pdf free download.Electric and optical fibre cables – Test methods for non-metallic materials – Part 504: Mechanical tests – Bending tests at low temperature for insulation and sheaths.
For the purposes of this document, the definitions given in IEC 60811-1 00 apply.
4 Test method
4.1 General
This part of IEC 60811 shall be used in conjunction with IEC 60811-100.
All the tests shall be carried out not less than 16 h after the extrusion or cross-linking of the
insulating or sheathing compounds.
Tests shall be carried out at the temperature specified in the relevant cable standard.
For tests on the insulation, the test is intended for insulated conductors of circular cross- section having an external diameter up to and including 12,5 mm and for sector-shaped cores where it is not possible to prepare dumb-bells.
For tests on sheaths, the test is intended for cables with an overall diameter up to and including 12,5 mm; and for flat cables, with a major axis dimension up to and including 12,5 mm.
If required by the relevant cable standard the test shall also be carried out on larger cables.
Note that equipment may need to be modified in accordance with the cable standard.
Otherwise, the insulation and sheath of larger cables shall be subjected to the elongation test described in IEC 60811-505.
4.2 Bending test at low temperature for insulation
4.2.1 Sampling and preparation of test pieces
Each core to be tested shall be represented by two samples of suitable length. After removal
of the coverings, if any, the samples shall be used as test pieces.
4.2.2 Apparatus
The apparatus recommended for this test is represented in Figure 1. with explanations. It consists essentially of one revolving mandrel and guiding devices for the test pieces. Other single-mandrel apparatus, substantially equivalent to the one represented in Figure 1, may also be used.
The apparatus shall be located in a suitable low temperature cabinet before and during the test.
4.2.3 Procedure
The test piece shall be fixed in the apparatus, as shown in Figure 1.
The apparatus with the test piece in position shall be maintained in the suitable low temperature cabinet at the specified temperature for a period of not less than 16 h. The cooling period of 16 h includes the time necessary for cooling down the apparatus.
If the apparatus has been pie-cooled, a shorter cooling period is permissible, but not less than 4 h at test temperature. If the apparatus and test specimens have been pie-cooled, a cooling time of 1 h after each test piece has been fixed to the apparatus is sufficient.
At the end of the prescribed time, the mandrel shall be rotated, in accordance with the conditions specified in 4.2,4, the test piece being guided so that it is bent tautly round the mandrel in a close helix. In the case of sector-shaped test pieces, the circular “back part of the test piece shall be in contact with the mandrel.
Afterwards, the test piece, still on the mandrel, shall be allowed to attain approximately
ambient temperature.
4.2.4 Test conditions
The cooling and test temperature shall be as specified for the type of compound in the relevant standard for the type of cable.
5 Test report
The test report shall be in accordance with that given in IEC 60811-100.IEC 60811-504 pdf free download.
