ThissectionofBS7870specifiesrequirementsfortheconstruction,dimensions andmechanicalandelectricalpropertiesofconcentriccopperwirecombined neutral/earth(CNE)servicecableshavingaratedvoltageof0.6/1(1.2)kV.Itis applicabletocablesthat,whenassessedbythespecifiedtests,producelower levelsofsmokeandcorrosivegasesunderexposuretofirethancables conformingtoBS7870-3.11. Itspecifiesrequirementsforthefollowingtypesofcable: singlephaseor3-phase; strandedcopperorsolidaluminiumconductors; XLPEinsulationandthermoplasticoversheathwithlowemissionofsmoke andcorrosivegaseswhenaffectedbyfire. ThissectionofBS7870isapplicabletocablesthataredesignedforamaximum continuousconductoroperatingtemperatureof90°Candforamaximumshort circuitconductortemperatureof250°C.