Servicing Power Supplies; Power Supply Overview - Oracle Exadata X10M Service Manual

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Servicing Power Supplies

This section describes how to service power supplies.
Power supplies are replaceable components that do not require you to power off the server
before servicing. For more information about replaceable components, see
Breakdown
The power supplies are located at the back of the server.

Power Supply Overview

The redundant power supply in the server supports concurrent maintenance, which enables
you to remove and replace a power supply without shutting down the server, if the other
power supply is online and working.
The server supports model A271 and A271a (1400 watt) power supplies. The power supply
(PS) provides conversion from the AC lines to the system, accepting 220 volts AC (VAC) only.
The PSUs are hot-pluggable, and in most cases provide fully redundant "1+1" power, allowing
the system to suffer the loss of a PS 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 power supply. Power supplies provide an over-
subscription mode (always enabled), which allows the system to operate with fault-tolerance,
even with modest excursions beyond the rated capacity of a single PS. This over-subscription
support is accomplished using hardware signaling between the PS and motherboard circuitry,
which can force the system to throttle processor (CPU) and memory power in the event that a
power supply is lost. The resulting power savings is enough to allow the system to continue
to run (in a lower-performance state) until the power problem is resolved.
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.
The following status indicators (LEDs) are lit when a power supply fault is detected:
• Front and back panel Fault-Service Required LEDs
• Rear Power Supply Fault-Service Required LED located on the server front panel
• Amber Fault-Service Required LED on the faulty power supply
For more information, see
and Replaceable Components.
Power Supply Status Indicators.
Illustrated Parts
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