BS 7870-4.20:2011+A1:2016

This standard BS 7870-4.20:2011+A1:2016 LV and MV polymeric insulated cables for use by distribution and generation utilities is classified in these ICS categories:

• 29.060.20 Cables

This section of BS 7870 specifies requirements for the construction, dimensions and mechanical and electrical properties of 6.35/11(12) kV three-core cables having either aluminium or copper conductors, cross-linked polyethylene (XLPE) or ethylene propylene rubber (EPR) extruded insulation, a copper wire metallic screen and an oversheath of one of the following compounds.

1. medium density polyethylene (MDPE) compound type DMP 5 (Type A cables);

2. thermoplastic compound type DMZ 4 for cables having a low emission of smoke and corrosive gases when affected by fire (Type B cables).

This section of BS 7870 is applicable to cables that are designed for a maximum continuous conductor operating temperature of 90 °C and for a maximum short-circuit conductor temperature of 250 °C.