Effect of system and installation requirements on the introduction of 11 kV polymeric insulated cables in London

11 kV polymeric insulated cables were first introduced onto the London distribution network in 1989, initially for specific projects but are now starting progressively to replace the use of the traditional paper insulated cable throughout the Company. London Electricity´s existing 11 kV system imposes several restrictive operational and installation requirements which have significantly influenced the design of the polymeric insulated cable and jointing accessories. The authors describe the construction of a compact polymeric insulated cable system. In particular the cable includes solid aluminium conductors for compactness and galvanised steel wires to meet the earth fault requirements. These design features and the need for compact re-enterable joints have provided challenges regarding installation and materials compatibility which are addressed. The early operational experience with this type of cable and accessories is also briefly covered