This part of IEC 60794, which is a family specification, specifies the optical fibre, cable elements, cable construction requirements, main requirements for installation and operating conditions, cable design characteristics and test for OPPC (optical phase conductor), used for carrying current as well as communication and data transmission. The corresponding environmental declaration can be built according to IEC TR 62839-1. The OPPC is a substitute for a conventional phase bare conductor containing optical fibres. Usually, the fibres are embedded loosely in protective buffer tubes. To fulfil mechanical and electrical requirements, an armouring of one or more layers with aluminium, aluminium alloy, and aluminium clad steel, galvanized steel or a mixture of them is helically stranded.