A maximum of six power supplies can be installed in the Enterprise Chassis. Either 2500W or 2100W power supplies are available. Two 2500W power supplies are standard in model 8721-A1x. Additional power supplies are orderable per the following table. All installed power supplies must be the same.



Both power supplies are 80 PLUS Platinum-certified. The 2500W modules are 2500 Watts output rated at 200VAC to 208VAC (nominal), and 2750W at 220VAC to 240VAC (nominal). The power supply has an oversubscription rating of up to 3538 Watts output at 200VAC. The power supply operating range is 200-240 VAC. The power supplies also contain two dual independently powered 40mm cooling fan modules that are powered not from the power supply itself, but from the chassis midplane. The fan modules are variable speed and controlled by the chassis fan logic.



The 2100W power supplies are 2100 Watts output power rated at 200-240VAC. Similar to the 2500W unit, this power supply also supports oversubscription, the 2100W unit can run up to 2895W for short duration. The 2100W supplies have two independently powered dual 40mm cooling fans, that pick up power from the midplane included within the power supply assembly.



80 PLUS is a performance specification for power supplies used within servers and computers. To meet the 80 PLUS standard, the power supply must have an efficiency of 80% or greater, at 20%, 50%, and 100% of rated load with PF of .09 or greater. The standard has several grades, such as Bronze, Silver, Gold, and Platinum.



With 2500W power supplies, the chassis allows configurations of power supplies to give N+N or N+1 redundancy. A fully configured chassis operates on only three 2500W power-supply units (PSUs) with no redundancy, but N+1 or N+N is advised. Three power supplies (or six with N+N redundancy) allow for a balanced three-phase configuration.



All power supply modules are combined into a single power domain within the chassis, which distributes power to each of the compute nodes, I/O modules, and ancillary components through the Enterprise Chassis midplane. The midplane is a highly reliable design with no active components. Each power supply is designed to provide fault isolation and is hot swappable.



In the case of the 2500W supplies, power monitoring of both the DC and AC signals allows the Chassis Management Module to accurately monitor the power supplies. Power monitoring with the 2100W power supplies is planned to be made available at a later date.