The redundant power supplies on the server support concurrent maintenance, which enables you to remove and replace a power supply without shutting down the server, provided that the other power supply is online and working.
The server supports model A256 (600 watt) power supplies. The A256 power supply unit (PSU) provides conversion from the AC lines to the system, accepting ranges from 100-240 volts AC (VAC). These PSUs are designed to be hot-swappable, and in most cases will provide fully redundant ”1+1” power, allowing the system to suffer the loss of a PSU or an AC feed with no loss to system availability.
In maximally configured systems, it is possible that the worst-case power consumption of the system could exceed the capacity of a single PSU. The PSUs provide an over-subscription mode, which allows the system to operate with fault-tolerance even with modest excursions beyond the rated capacity of a single PSU. This over-subscription support is accomplished using hardware signaling between the PSU and motherboard circuitry, which can force the system to throttle maximally CPU and memory power in the event that a PSU is lost. The resulting power savings will be enough to allow the system to continue to run (in a lower-performance state) until the power problem is resolved.
The following indicators (LEDs) are lit when a power supply fault is detected:
Rear Power Supply Fault LED located on the server front panel (see Front Panel Controls and Indicators)
If a power supply fails and you do not have a replacement available, leave the failed power supply installed to ensure proper airflow in the server.
For more information, refer to the following topic and procedures: