BS EN 60811-401:2012 pdf download

BS EN 60811-401:2012 pdf download.Electric and optical fibre cables— Test methods for non-metallic materials Part 401: Miscellaneous tests — Thermal ageing methods —Ageing in an air oven.
– complete cable (see Annex C).
Compounds of obviously different compositions shall not be tested at the same time in the same oven
Five test pieces, as specified in IEC 60811.501 shall be suspended vertically and substantially in the middle of the oven so that each test piece is at least 20 mm from any other test pieces
The test pieces shall not occupy more than 2 $ of the volume of the oven.
The test pieces shall be kept in the oven at the temperature and for the time specified for the material in the relevant standard for the type of cable.
As soon as the ageing period is completed, the test pieces shall be removed from the oven and left at ambient temperature, avoiding direct sunlight, for at least 16 h.
4.2.3.3 Ag.ing procedur. for t.st pieces pr.par.d from conductors above 16 mm2
The following procedure shall be used when the conductor and the separator. if any, cannot be removed without damaging the insulation after ageing.
The test pieces prepared as described En B.2.3.1 shall be placed substantially in the middle of the oven so that each test piece is at least 20 mm from any other test pieces. They shall be supported at both ends and the insulation shall not contact any oblect other than the binding wire. The test pieces shall not occupy more than 2 % of the volume of the oven, and they shall be kept in the oven at the temperature and for the time specified in the relevant standard for the type of cable,
As soon as the ageing period is completed, the test pieces shall be removed from the oven. left at ambient temperature avoiding direct sunlight, for at least 16 h, dumb-bell are prepared as described in B.2.3.2.
4.2.3.4 AgeIng procedur. for pieces of complete cable
The three test pieces of cable as described in Clause C.1 shall be suspended vertically and substantially in the middle of the oven at least 20 mm away from any other piece and shall not occupy more than 2 % of the volume of the oven.
The test pieces of cable shall be kept in the oven at the temperature and for the time specified in the relevant standard for the type of cable.
As soon as the specified heating period is completed, the test pieces of cable shall be removed from the oven and left at ambient temperature, avoiding direct sunlight, for at least 16 h.
4.2.4 Measurements
Determination of the mechanical properties on aged dumb-bell and/or tubular test pieces obtained directly after ageing or prepared after ageing, according to the case (see 8.2.3 or Clause C.2) shall then be carried out in accordance of IEC 60811-501.
4.2.5 Expression of results
Calculate the tensile strength end the elongation at break, according to the definitions ghren in IEC 6081 1.501.
A.1.4 If a watt-hour or kilowatt-hour meter is used, the reading of the total energy consumption registered by the meter shall be divided by the duration of the test, measured as a fraction of an hour. If a household kilowatt-hour meter is used, the dial units are too large to enable a sufficient accuracy to be obtained over a reasonably short test, and the rotating disc with which these meters are provided shall be used therefore as the power consumption Indicator. The meter shall be put Into operation until the index mark on the disc Is opposite the centre of the window; it shall then be disconnected until the start ot the test.
To reduce the possible error, the period of test shall be long enough to permit 100 revolutions of the disc and the test shall preferably be ended when the mark on the disc is visible, If, however, the mark is out of sight at the end of the test, an estimated fraction of a revolution shall be added. The test shall be started and stopped at corresponding points on the on-ofV heating cycle (eg.. at the moment when the heaters are switched on by the thermostat).
A.2 Method 2 — Direct and continuous method
A.2.1 Description of the equipment
Starting from the high-pressure air source, i.e. trom a pipe system or air cylinders:
A.2.1.1 Air pr.ssure r.gulator
A device to reduce the air pressure from the many atmospheres of the supply mains to the quite low-pressure values needed for supplying the oven, It is equipped with an adjustable valve which permits a constant pressure downstream.