Cisco UCS X9508, Руководство по установке

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N+2 Power Supply Configuration
In an N+2 configuration, the chassis contains a total number of power supplies to satisfy system power
requirements, plus two additional power supplies for redundancy.
In N+2 redundant mode, a maximum power load of 11.2KW is supported with four active modules. The
11.2KW maximum power load is only possible at high input voltage range (200-240VAC). In low input
voltage range (100-127VAC nominal), the maximum delivered power would be 5.6KW.
Note
An N+2 configuration occurs when:
• Of the six total PSUs that are participating in the N+2 configuration, four are turned on and configured
to operate in Active mode
• All four active PSUs equally share the power load for the chassis.
• The remaining two PSUs are turned on and configured to provide Standby power to the chassis so that
the power supplies can take over operation if two power supplies should fail, as long the number of
operating power supplies does not drop below the required minimum.
If one or two power supplies should fail, the surviving supplies can provide power to the chassis. In addition,
the Cisco Intersight interface supports turning on any "turned-off" power supplies to bring the system back
to N+2 status.
Grid Configuration
With grid power configuration (also called N+N redundancy), each set of three PSUs has its own input power
circuit, so each set of PSUs is isolated from any failures that might affect the other set of PSUs. If one input
power source fails, causing a loss of power to three power supplies, the surviving power supplies on the other
power circuit continue to provide power to the chassis.
Grid redundant mode requires the chassis load to be limited to 8.4KW for high input voltage range
(200-240VAC) and 4.2KW for low input power range for a maximum grid configuration (3+3). For a 2+2
minimum configuration, the chassis load is limited to 5.6KW for high line input voltage and 2.8KW for low
line input voltage.
Caution
Grid redundant mode is configured when:
• all six PSUs are in Active mode to provide power
• two sets of three PSUs are each connected to separate facility input power sources, including separate
cabling for each set
• For grid redundant mode, the total number of PSUs should always be divided equally. So, a grid power
configuration supports 3+3 (maximum configuration per input power source) or 2+2 (minimum
configuration per power input source).
The grid power configuration is sometimes used when you have two separate facility input power sources
available to a chassis. A common reason for using this power supply configuration is if the rack power
distribution is such that power is provided by two PDUs and you want redundant protection in the case of a
PDU failure.
Cisco UCS X9508 Server Chassis Installation Guide
12
Overview
N+2 Power Supply Configuration