HD 620 applies to cables with extruded insulation and for rated voltages Uo/U(Um) from 3.6/6 (7.2)kV up to 20.8/36(42) kV uded in power distribution systems of voltages not exeeding the maximum r.m.s value of the system voltage Um.
This part (Part 1) specefies the general requirements applicable to these cables, unless otherwise specified in the particular sections of this HD.
Test methods specified are given EN 60811, HD383, HD405, HD605 and in IEC 60229, IEC 60840, IEC 60885-2 and IEC 60885-3.
NOTE 1 HD 405 is currently under revision. Parts 1 and 2 will be re-issued within EN 50265, and Part 3 as EN 50266.
Attention should be drawn to the fact that a significant number of sections include references to long them tests which are collected in Hd 605. These long-term tests are considered as necessary and reflect the best avalible knowledge for the existing cable design. They are related to specific designs and different philosophies concerning adequate measures against the influence of water. However it is the firm intention to reduce this large number of different tests, but more experience should be gained before starting to rationalise this important matter.
The particular types of cables are specified in Parts 5 to 9.
NOTE 2 cables orginally in Parts 3 and 4 have now been withdrawn.