Arrangement for checking damage to conductors

Introduction:

12.2.5 Terminals with screw clamping shall be so designed and constructed that they clamp the conductor(s) without undue damage to the conductor(s).

Compliance is checked by the following test.

The terminal is placed in the test apparatus according to figure 11 and fitted with rigid, solid,stranded and/or flexible conductor(s), according to table 3 first with the smallest and then with the largest nominal cross-sectional area, the clamping screw(s) or nut(s) being tightened with

the torque according to table 6.

Where rigid stranded conductors do not exist, the test may be made with rigid solid conductors only. In this case, there is no need for further tests. The length of the test conductor shall be 75 mm longer than the height (H) specified in table 9.

The end of the conductor is passed through an appropriate bushing in a plate positioned at a height (H) below the equipment, as given in table 9. The bushing is positioned in a horizontal plane such that its centre line describes a circle of 75 mm diameter, concentric with the centrof the clamping unit in the horizontal plane; the platen is then rotated at a rate of (10 ± 2) r/min.

The distance between the mouth of the clamping unit and the upper surface of the bushing shall be within ±15 mm of the height specified in table 9. The bushing may be lubricated to prevent binding, twisting, or rotation of the insulated conductor.

A mass as specified in table 9 is suspended from the end of the conductor. The duration of the test is approximately 15 min.

During the test, the conductor shall neither slip out of the clamping unit nor break near the clamping unit, nor shall the conductor be damaged in such a way as to render it unfit for further use.