IEC 60811-2-1:2001 pdf download
IEC 60811-2-1:2001 pdf download.Common test methods for insulating and sheathing materials of electric and optical cables一 Part 2-1: Methods specific to elastomeric compounds – Ozone resistance, hot set and mineral oil immersion tests.
3 ApplicabIlity
Conditioning values and testing parameters are specified for the most common types of insulating and sheathing compounds and of cables, wires and cords
4 Type tests and other tests
The test methods described in this standard are intended, in the first instance, to be used for type tests. In certain tests, where there are essential differences between the conditions for type tests and those for more frequent tests. Such 55 routine tests, these differences are Indicated.
5 Pro-conditioning
All the tests shall be carried Out not less than 16 h after the extrusion or vulcanization (or cross-linking), If any. of the Insulating or sheathing compounds.
If the test is carried out at ambient temperature, the test-pieces shall be kept for at least 3 h at a temperature of 23 C ± 5 C.
6 Test temperature
Unless otherwise specified, tests shall be made at ambient temperature.
7 MedIan value
When several test results have been obtained and ordered in an increasing or decreasing succession, the median value is the middle value if the number of available values is odd, and is the mean of the two middle values if the number is even.
8 Ozone resistance test
Warning: Attention is drawn to the toxicity of ozone. Precautions should be taken to minimize exposure of personnel to it at all times and the concentration in the workroom environment should not be allowed to exceed 0,1 ppm (parts ozone per million parts air by volume), or the value in the current industrial hygienic standard, whichever is the lower.
8.1 Test method
8.1.1 Test apparatus
a) A device for generating a controlled amount of ozone.
b) A means for circulating ozonized air under controlled conditions of humidity and temperature through a chamber containing the test pieces to be tested
C) A means for determination of ozone concentration.
d) A suitable device for the clamping and elongation of test pieces.
e) Cylindrical mandrels consisting of wood or metal.
f) A desiccator filled with silica gel or equivalent material.
g) An accurate laboratory balance reading to 0,1 mg.
8.1.2 Sampling
8.1.2.1 Sampling of insulation
Whether the cable is single or multicore, only one core needs to be tested. Sufficient length of core shall be cut from a position not less than 1.5 m from the end of the length of cable to provide two test pieces, unless the core has an extruded semi-conductor layer on the outside. in which case sufficient length for four test pieces shall be taken.
Any sample that shows signs of mechanical damage shall not be used for the tests.
8.1.2.2 Sampling of sheath
One sample of the cable or cord to be tested, or of the sheath removed from the cable, shall be taken of sufficient size to provide a minimum of two test pieces.
Any sample that shows signs of mechanical damage shall not be used for the tests.
8.1.3 Preparation of test pIeces
8.1.3.1 Test pieces of insulation
Any protective coverings present on the core shall be removed without damaging the insulation. unless they were applied directly to the insulation prior to vulcanization and are adherent to it.
If the core has a semi-conducting layer in the form of tape on the outside, this shall be removed.
If the core has an extruded semi-conducting screen on the outside, this shall be removed from two test pieces and left in position on the other two.
8.1.3.2 Test pieces of sheath
Two dumb-bell test pieces shall be prepared in accordance with 9.1.3 and 9.2.3 of IEC 60811-1-1. The minimum test piece thickness shall be 0,6 mm.
In the case of cables of such small size that it is not possible to prepare dumb-bell test pieces, the test method used shall be that specified for insulation.
8.1.4 Conditioning and deformation procedure of test pieces
8.1.4.1 Test pieces of insulation
If the core does not have an extruded semi-conducting screen, one test piece shall be bent In the direction and plane of Its existing curvature, without twisting, for one complete turn around a mandrel, and bound with twine or tape where the ends cross, and a second test piece of the same core shall be bent similarly in the plane of its existing curvature but in the opposite direction.
If the core as manufactured has an extruded core screen on the outside, two test pieces, one with the semi-conducting layer removed and one with the semi-conducting layer left in position, shall be bent. as above, in each direction.
