IEC 60811-509-2017 pdf free download
IEC 60811-509-2017 pdf free download.Electric and optical fibre cables – Test methods for non-metallic materials – Part 509: Mechanical tests – Test for resistance of insulations and sheaths to cracking (heat shock test).
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60811-100 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 of the insulating or sheathing compounds
Unless otherwise specified, tests shall be carried out at room temperature. The heat shock test was specifically developed for PVC compounds. The use of this test for other types of compounds needs careful consideration.
NOTE In the absence of any requirement in the relevant cable standard, Annex A in this standard gives a
recommendation for the test conditions and test requirements.
4.2 Apparatus
The apparatus consists of the following parts:
a) an air oven capable of maintaining the temperature and tolerance specified;
b) mandrels of sufficient length made of metal or other suitable material.
4.3 Sample and test piece preparation for insulations
4.3.1 General
Each core to be tested shall be represented by two samples of suitable length taken from two places separated by at least 1 m. External coverings, if any, shall be removed from the insulation.
The test pieces shall be prepared in one of the three following ways:
a) For cores with an overall diameter not exceeding 12,5 mm, each test piece shall consist of a piece of core.
b) For cores with an overall diameter exceeding 12,5 mm and having an insulation thickness not exceeding 5 mm, and for all sector-shaped cores, each test piece shall consist of a strip taken from the insulation whose width shall be at least I ,5 times its thickness, but not less than 4 mm. The strip shall be cut in the direction of the axis of the conductor. In the case of sector-shaped cores, it shall be cut out of the aback” of the core.
c) For cores with an overall diameter exceeding 12,5 mm and a wall thickness exceeding
5,0 mm, each test piece shall consist of a strip cut in accordance with item b) and then
ground or cut (avoiding heating) on the outer surface, to a thickness between 4,0 mm and
5,0 mm. This thickness shall be measured on the thicker part of the strip, whose width
shall be at least 1,5 times the thickness.
4.3.2 Procedure
Each test piece shall be tautly wound and fixed, at ambient temperature, on a mandrel to form a close helix, as given below:
a) For test pieces prepared in accordance with 4.3.1 a), and—for flat cables with major axis not exceeding 12,5 mm, the diameter of the mandrel and the number of turns shall be as given below in Table 1. The mandrel diameter shall be based on the minor dimension of the core which is wound on with its minor axis perpendicular to the mandrel.IEC 60811-509 pdf download.
