IEC 60227-2-2003 pdf – Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 V – Part 2: Test methods

IEC 60227-2-2003 pdf – Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 V – Part 2: Test methods.
1 General 1.1 General requirements The methods of carrying out the tests specified in all parts of IEC 60227 are given in this part and the following publications: IEC 60227-1:1993, Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 V – Part 1: General requirements IEC 60332-1:Tests on electric cables under fire conditions – Part 1: Test on a single vertical insulated cable IEC 60811-1-1:1993, Common test methods for insulating and sheathing materials of electrical cables – Part 1: Methods for general application – Section 1: Measurement of thickness and overall dimensions – Test for determining the mechanical properties 1.2 Applicable tests The tests applicable to the types of cables are given in the particular specifications (IEC 60227-3, IEC 60227-4, etc.). 1.3 Classification of tests according to the frequency with which they are carried out The tests specified are type tests (symbol T) and/or sample tests (symbol S) as defined in 2.2 of IEC 60227-1. The symbole T and S are used in the relevant tables of the particular specifications (IEC 60227-3, IEC 60227-4, etc.). 1.4 Sampling If a marking is in relief in the insulation or sheath, the samples used for the tests shall be taken so as to include such marking. For multicore cables, except for the test specified in 1.9, not more than three cores (of different colours, if applicable) shall be tested unless otherwise specified. 1.5 Pre-conditioning All the tests shall be carried out not less than 16 h after the extrusion of the insulating or sheathing compounds. 1.6 Test temperature Unless otherwise specified, tests shall be made at ambient temperature.
1.7 Test voltage Unless otherwise specified, the test voltages shall be a.c. 49 Hz to 61 Hz of approximately sine-wave form, the ratio peak value/r.m.s. value being equal to 2 with a tolerance of ±7 %. The values quoted are r.m.s. values. 1.8 Checking of the durability of colours and markings Compliance with this requirement shall be checked by trying to remove the marking of the manufacturer’s name or trade mark and the colours of cores or numerals by rubbing lightly ten times with a piece of cotton wool or cloth soaked in water. 1.9 Measurement of insulation thickness 1.9.1 Procedure The thickness of insulation shall be measured in accordance with 8.1 of IEC 60811-1-1. One sample of cable shall be taken from each of three places, separated by at least 1 m. Compliance shall be checked on each core of cables having up to five cores, and on any five cores of cables with more than five cores. If withdrawal of the conductor is difficult, it shall be stretched in a tensile machine or the piece of core shall be loosened by stretching or some other suitable means that does not damage the insulation. 1.9.2 Evaluation of results The mean of the 18 values (expressed in millimetres) obtained from the three pieces of insulation from each core shall be calculated to two decimal places and rounded off as given below, and this shall be taken as the mean value of the thickness of insulation. If in the calculation the second decimal figure is 5 or more, the first decimal figure shall be raised to the next number, thus, for example, 1,74 shall be rounded off to 1,7 and 1,75 to 1,8. The lowest of all values obtained shall be taken as the minimum thickness of insulation at any place. This test may be combined with any other measurements of thickness, for instance those of 5.2.4 of IEC 60227-1. 1.10 Measurement of sheath thickness 1.10.1 Procedure The thickness of sheath shall be measured in accordance with 8.2 of IEC 60811-1-1. One sample of cable shall be taken from each of three places, separated by at least 1 m.