BS EN 3475-512:2021 pdf free.Aerospace series — Cables, electrical,aircraft use— Test methods Flexure endurance.
BS EN 3475-512 Take specimens of adequate length from a finished cable and install them on apparatus describedhereafter.
This test makes it possible to determine the resistance of the cable to cycles of repeated flexing.
With the cable vertical, a cycle is defined by a rotation of 90° left, return to the vertical, rotation of 90°right and return to the vertical.The damage is detected by conductor breakage and thus an interruption of electrical continuitybetween the two ends of the tested specimen.The test is normally performed on gauge 20 cables.lt is carried out at ambient temperature.
Apparatus and installation of specimensThe apparatus is described by Figure 1.
lt is fitted with a counter and an automatic stop device controlled by interruption of electricalcontinuity.
The rotation speed shall be a uniform rate of (18± 2) cycles/min.
The space between mandrels is equal to the maximum diameter of the tested cable.The mandrel diameter D and weight M are specified in the product standard.
After installing a specimen and before commencing the full test, perform a preliminary run and,if necessary, adjust the distance, the mandrels and the attached weight such that possible resonanceeffects are avoided.For the actual test, actuate the detection circuit,reset the counter and run themachine until auto shut down takes place.
Method A: flexure endurance test of the conductor.
This test shall be performed on a minimum of 3 (three) specimens.
The mean value of this test shall be greater than the value specified in the product standard.
The number of cycles between the beginning of the test and the ending triggered by the detectionsystem shall be greater than the value specified in the product standard.Method B: flexure endurance of the cable insulation.
Three additional specimens shall be submitted to the number of cycles requested in the specification.These specimens shall pass the voltage proof test EN 3475-302 (immersion test).Unless otherwise specified, only method A is required.BS EN 3475-512 pdf download.