HD 621 applies to impregnated paper insulated cables for rated voltages Uo/U(Um) from 3,6/6(7,2)kV up to 20,8/36(42)kV used in power distribution systems.
This part (Part 1) specifies the general requirements applicable to these cables, unless otherwise specified in the particular sections of this HD.
Test methods specified are given in HD 605, EN 60811, HD 383 and HD 405 and in IEC 55-1 and IEC 229.
Part 2 covers all those test methods which are specific to paper insulated cables, and not included in HD 605.
The particular types of cables are specified in Parts 3 and 4.