Standards
The European Telecommunications Standards Institute (ETSI) has developed standard EN 300 132-3-1, which describes the characteristics of a DC bus between 260 and 400 V, and EN 301 605, which describes the earthing and bonding of 400 VDC data and telecom (ICT) equipment. Additional standards have been published by the Emerge Alliance, the International Telecommunication Union (ITU-T), and the International Electrotechnical Commission (IEC).