This Recommendation specifies a power feeding architecture for power feeding systems of up to 400 V direct current (VDC) at telecommunications centres@ datacentres and customer premises [ITU-T L.1200]. This Recommendation aims to provide a reference of power feeding architecture for an up to 400 VDC power feeding system with high reliability@ safety and manageability. This Recommendation covers the following items for power feeding systems of up to 400 VDC: 1) configuration of power feeding systems of pure up to 400 VDC and hybrid power feeding systems with up to 400 VDC and alternating current (AC) power feeding systems; 2) requirements of the main basic elements for power feeding systems of up to 400 VDC@ such as rectifiers@ power distribution units (PDUs)@ batteries and distribution power lines; 3) monitoring and management functions. This Recommendation ensures a safe@ operable@ electromagnetic compatibility- (EMC)-compliant and reliable cohabitation of power feeding systems of up to 400 VDC with AC and ?48 VDC [ETSI EN 300 132-2] systems in sites combining these power feeding interfaces. The full description of a battery@ grid AC supply@ backup generator and power supply units (PSUs) in ICT equipment and renewable or distributed energy sources are outside of the scope of this Recommendation@ but indications are given on their influence on the architecture of power feeding systems of up to 400 VDC. This Recommendation describes extended power feeding architectures using up to 400 VDC e.g.@ hybrid redundant DC and alternating current (AC) power feeding based on [ITU-T L.1201].