Power Cables (1,8/3 "3,6" KV)

Cables with a rated voltage of 1,8/3 (3,6) kV shall have a metal layer surrounding the cores

Either individually or collectively:

Acc. to IEC 60502-1 Sub clause (7.4)

Cables having only a collective metal layer

Cables shall have an inner covering over the laid-up cores.

The inner covering and fillers shall be non-hygroscopic.

Cables having a metal layer over each individual core

The metal layers of the individual cores shall be in contact with each other.

Cables with an additional collective metal layer of the same material as the underlying individual metal layers shall have an inner covering over the laid-up cores.

The inner covering and fillers shall be non-hygroscopic.

When the underlying individual metal layers and the collective metal layer are of different materials, they shall be separated by an extruded sheath of one of the materials specified

For cables having neither Armour, nor concentric conductor, nor other collective metal layer,the inner covering may be omitted, provided the outer shape of the cable remains practically circular.

This rated voltage is rare case so many designer forget this point ( that cables shall have metal Layer),Be careful in similar designs even it is LV but need to make attention .