A procedure for validating the use of lathed tapes for electrical breakdown testing

The electrical breakdown strength of cable insulation is normally determined by performing breakdown tests on lengths of as-manufactured cables. However, such an approach, which tests the design of the cable, manufacturing tolerances etc, is less relevant when it is the properties of the insulation that are of principle interest. In this case, the breakdown strength of tapes lathed from small lengths of cable can be studied in an attempt to obtain material parameters, The authors consider the effect of mechanical damage on crosslinked polyethylene (XLPE) tapes, and the validity of lathing as a means of obtaining representative electrical data.