IEC 60227-2:2003 pdf free download

IEC 60227-2:2003 pdf free download Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 V – Part 2: Test methods
1.7Test voltage
Unless otherwise specified, the test voltages shall be a.c. 49 Hz to 61 Hz of approximatelysine-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.
1.8Checking of the durability of colours and markings
Compliance with this requirement shall be checked by trying to remove the marking of themanufacturer’s name or trade mark and the colours of cores or numerals by rubbing lightly tentimes 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 lEC 60811-1-1.Onesample 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 fivecores of cables with more than five cores.
lf withdrawal of the conductor is difficult, it shall be stretched in a tensile machine or the pieceof core shall be loosened by stretching or some other suitable means that does not damage theinsulation.
1.9.2 Evaluation of results
The mean of the 18 values (expressed in millimetres) obtained from the three pieces ofinsulation from each core shall be calculated to two decimal places and rounded off as givenbelow,and this shall be taken as the mean value of the thickness of insulation.
lf in the calculation the second decimal figure is 5 or more，the first decimal figure shall beraised 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 anyplace.
This test may be combined with any other measurements of thickness, for instance those of5.2.4 of IEc 60227-1.
1.10Measurement of sheath thickness1.10.1 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.
The lowest of all values obtained shall be taken as the minimum thickness of sheath at anyplace.
This test may be combined with any other measurements of thickness，for instance those of5.5.4 of lEC 60227-1.
1.11 Measurement of overall dimensions and ovality
The three samples taken in accordance with 1.9 or 1.10 shall be used.
The measurement of the overall diameter of any circular cable and of the overall dimensions offlat cables with a major dimension not exceeding 15 mm shall be carried out in accordance with8.3 of IEC60811-1-1.
For the measurement of flat cables with a major dimension exceeding 15 mm, a micrometer, aprofile projector or similar appliance shall be used.
The mean of the values obtained shall be taken as the mean overall dimension.
For checking the cable ovality of circular sheathed cables, two measurements shall be made atthe same cross-section of the cable.
Electrical tests
2.1 Electrical resistance of conductors
ln order to check the electrical resistance of conductors, the resistance of each conductor shallbe measured from a sample of cable of at least 1 m in length, and the length of each sampleshall be measured.