Equipment Engineering (EE); Power Supply Interface at the Input to Telecommunications Equipment Interface Part 2: Interface Operated by Direct Current (DC)
"This European Telecommunication Standard (ETSI defines: - the output performance of the Direct Current (DC) power equipment at the interface ""A""; - the input requirements of the telecommunications equipment connected to interface ""A"" powered by DC. The DC voltage at interface ""A"" may be derived from the AC primary supply with or without a buffer battery. This ETS also makes reference to safety specifications which are in accordance with the relevant international standards. This ETS aims at providing compatibility between the power supply equipment and the power consuming telecommunications equipment and also between different system blocks connected to the same power supply. NOTE 1 : To ensure satisfactory Performance@ the merging of telecommunications equipment into installations is subject to the prevailing conditions of that installation and is subject to the agreement of relevant parties. NOTE 2: This ETS is applicable to 48 VDC power supply interfaces. However@ during a transitional period@ other DC voltages may be used in existing installations. Annex A gives guidance on merging equipment with existing -60 VDC supply systems."