Environmental Engineering (EE) - Power supply interface at the input to telecommunications and datacom (ICT) equipment - Part 3: Operated by rectified current source, alternating current source or direct current source up to 400 V - Sub-part 1: Direct current source up to 400 V; (Endorsement of the English version EN 300 132-3-1 V2.1.1 (2012-02) as German standard)