Oracle Exadata Storage Server X7-2 EF, Service Manual

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Servicing Power Supplies
This section describes how to service power supplies. Power supplies are replaceable units that
do not require you to power off the server. For more information about replaceable units, see
“Illustrated Parts Breakdown” on page 22 and “Replaceable Units” on page 23 .
The power supplies are located at the back of the server. See the following procedures:
■
“Power Supply Overview” on page 81
■
“Remove a Power Supply” on page 82
■
“Install a Power Supply” on page 84
Power Supply Overview
The server redundant power supplies support concurrent maintenance, which allows 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 A266 (1200 watt) power supplies. The A266 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-pluggable, and in most cases, 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 processor (CPU) and memory power in the event that a PSU 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.
The following status indicators (LEDs) are lit when a power supply fault is detected:
Servicing Power Supplies 81