The power shelf is largely a passive backplane that houses six rectifiers and one Power Shelf Controller (PSC).
The Power Shelf Controller (PSC) is a custom remote monitoring unit (RMU) for the Murata MWOCES-191-M-B power shelf used in the Oxide Rack. The PSC plugs into the RMU slot on the back of the power shelf and is designed to enable the following control plane features:
Detect when power supply units (PSUs) are inserted or removed from the power shelf
Read PSU serial numbers and other Field Replaceable Unit ID (FRUID) information
Turn individual PSUs on and off
Monitor rack-level power consumption
Monitor PSU state of health
Update PSU firmware
The PSC communicates on the management network, uses an Ignition target for presence detection, identification, and fault monitoring. It leverages the same hardware root of trust and service processor as the Gimlet server sled and Sidecar rack switch.
The power shelf accepts 200-240 VAC in either a Delta or Wye configuration, and outputs up to 18 kW at 54.5 V DC. The front panel of the power shelf holds six Murata MWOCP68-3600-D-RM hot-swappable power supply units (PSUs). The rear panel of the power shelf has connectors for ac power inputs, DC power outputs, an auxiliary connector for a battery backup shelf (not offered in the Oxide rack), and an optional MWOC-RMU-2 Series RMU. A passive backplane inside the power shelf breaks out each PSU’s enable signal, power good signal, and PMBus interface to the RMU connector.
PSU firmware can be flashed over the PMBus interface in the RMU connector. In the Oxide Rack, the PSC allows operators to perform PSU firmware upgrades without physically removing the PSU from the rack.