This Standard covers d.c. metal-enclosed and non-metallic enclosed switchgear assemblies used in indoor stationary installations of traction systems, with nominal voltage not exceeding 3 000 V. It is intended that individual items of equipment, for example circuit breakers, housed in the assembly are designed, manufactured and individually tested (simulating the enclosure when necessary) in accordance with their respective parts of EN 50123 or, when appropriate, with another applicable standard. NOTE 1 The requirements covered in EN 50123-6 are those concerning the assembly as such, its enclosure and the mutual influence of the equipment enclosed. NOTE 2 EM