Methods and requirements for providing electrical power to Rack Enclosures for Information Technology Equipment are described. The need for the rack power system to adapt to changing requirements is identified and quantified. The requirements for a rack power system that can adapt to changing needs are defined.

Information Technology (IT) refreshes in the data center typically occur every 1.5 to 2.5 years. As equipment is changed, the power requirement, the voltage requirement, the redundancy requirement, and the connector requirement often change as well. As rack enclosures have become the standard means for housing and organizing computing and communication systems, the power distribution system for the rack enclosure must adapt to these changing requirements. The power requirements of modern computing equipment vary as a function of time depending on the computational load. Until the year 2000, this variation was very small and could be ignored for almost all computing and communication systems. However, the implementation of power management technologies into processors and servers began during the year 2000 and today nearly all computing equipment has a substantial variation in power consumption in response to the computing load. This variation can be as high as 200% of the baseline power consumption of the equipment. The power distribution system design for a rack enclosure must comprehend this variation.