The OCP rack offers the best possible packing density and space utilisation, because the 21" standard and 600 mm width ensure optimum rack utilisation. Special OCP servers are used in the racks, operating with an electrical supply voltage of 12 V / 48 V DC (direct current) and mechanically optimised for insertion in the 21" rack.
The special OCP server hardware is supplied with power via the rear-mounted DC busbars. Different busbar systems are used depending on the OCP rack version. The OCP specification V 1.2 includes up to three 12 V DC busbars, each of which can additionally be divided horizontally into 2 power zones, thereby reducing the current load on each bar/increasing the DC output available. Depending on the rack population with DC busbars, outputs of 6.6 kW and 13.2 kW all the way up to 40 kW are possible.
Open Compute rack design
In the new OCP specification V 2.0, the supply voltage is increased to 48 V DC. This means up to 36 kW of electrical output is available for each rack. In this case, however, the special 48 V OCP server hardware is supplied via an end-to-end DC busbar for each rack. The connector and the busbar design are different from the design for OCP racks with a 12 V DC supply, though.
Special OCP power packs that generate the direct current required for the OCP servers from the existing 3-phase alternating current are installed in the racks to power the servers. These power packs support modular rack mounting and monitoring via the network (via SNMP). The individual power pack blocks generate typical outputs of 3 kW and are connected in parallel.
Battery backup units can optionally be integrated into the OCP rack to supply backup power for a few minutes in the event of power failures.