Brocade FastIron Ethernet Switch Administration Guide - Manual (Page 266)

For safety reasons, all PoE power supplies installed in the chassis must operate at the same voltage
mode, either 52 volts or 54 volts. The system will select the voltage mode of the power supply with the
lowest supported voltage as the voltage mode for all PoE power supplies installed in the chassis. For
example, in a FSX 800 chassis with one 52-volt capable PoE power supply and one 54-volt capable
PoE power supply, both power supplies will be configured dynamically to operate at 52 volts.
PoE+ voltage selection occurs during each of the following events:
• When the device is powered ON or is rebooted
• When a PoE power supply is installed in the chassis
• When a PoE power supply is removed from the chassis
These events are described in detail in the following sections.
NOTE
A PoE power supply upgrade does not persist beyond a single power cycle. Therefore, an upgrade will
occur automatically each time a power supply is re-inserted in the chassis.
You can use the show inline power detail command to display detailed information about the PoE
power supplies installed in a FastIron PoE device. For more information refer to section
Displaying
detailed information about PoE power supplies on page 284.
CAUTION
The SX-POE-AC-PWR power supply is designed exclusively for use with the BrocadeFSX PoE
devices. The power supply produces extensive power to support 802.3af and 802.3at
applications. Installing the power supply in a device other than the BrocadeFSX PoE device will
cause extensive damage to your equipment.
Voltage selection during bootup
During bootup, the system will select the voltage mode (either 52 volts or 54 volts) of the power supply
with the lowest supported voltage as the voltage mode for all PoE power supplies installed in the
chassis. For example, if there is at least one power supply that supports 52 volts maximum, then all
power supplies will be configured to operate at 52 volts, even if other supplies are 54 volts-capable.
Once the operating voltage is applied, the system will display and log a warning message similar to
the following:
device(config)#
Power supply 1 (from left when facing front side) detected.
Power supply 1 (from left when facing front side) is up.
WARNING: PoE power supplies in slots 1 are down rev. PoE/PoE+ function will work,
but output power may be less than 50V under worst case load.
If all power supplies are 54 volts-capable, then all power supplies will be configured to operate at 54
volts. In this case, the system will not display or log a warning message.
Voltage selection when a PoE power supply is installed
When a PoE power supply is hotswapped into the chassis, the system will automatically adjust the
voltage to match that of the PoE power supply or supplies that are currently installed in the chassis.
The following examples describe how the voltage is selected when a PoE power supply is installed:
Voltage selection during bootup
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