Presentation on the Server Power Supply Loading Guideline. The purposes of this Guideline is to ensure that the loading for each DC bus for a multi output server power supply is consistent when measuring power supply efficiency and to allow consistency in comparing server power supply efficiency reported by vendors as part of the electrical specification.
Loading guidelines have been developed based on proportional allocation of load current for each DC bus rail based on the MAXIMUM CURRENT rating of each DC bus rail. For 100% load level the maximum rating for each DC bus rail is decreased proportionately to ensure that the total combined loading for all the output busses is equal to the overall rating of the power supply AND the maximum combined rating for a subset of the output busses (e.g., +5V and +3.3V) is not exceeded.
Author(s): Mansoor, A.