Extreme Networks Summit X150 Series, Hardware Installation Manual

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External Power Supplies
Summit Family Switches Hardware Installation Guide
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Internal-to-External Power Supply Transfer
This section describes the conditions that would cause the Summit X450e-48p or X250e-48p switch to
draw power from the external power unit.
Internal Power Supply Failure with Single EPS-600LS Module. When an EPS-C with a single
EPS-600LS is connected to the Summit X450e-48p or X250e-48p switch and the internal power supply
fails, power is drawn from the EPS-600LS without power interruption to the PoE-connected devices.
Two or Three EPS-600LS Modules. When the Summit X450e-48p or X250e-48p switch detects that an
EPS-C is connected and providing stable power from two or three EPS-600LS power modules, the PoE
power budget is automatically recalculated to enable 740 W of PoE power. The internal power supply is
disabled to prevent damage from excessive current demands beyond the capabilities of the internal
power supply.
External-to-Internal Power Supply Transfer
This section describes what happens if power from an external power module either fails or is
disconnected.
Active Internal Power Supply with Single 600-LS Module Failure. When an EPS-C with a single
EPS-600LS module is connected to the Summit X450e-48p or X250e-48p switch and the EPS-600LS fails
or is disconnected, power is drawn from the internal power supply without power interruption to the
PoE-connected devices.
Inactive Internal Power Supply with a Dual EPS-600LS Configuration and Module Failure. In an
EPS-c chassis with two EPS-600-LS power modules, it is possible for one external power module to fail
while the second power module continues to function. If one EPS-600LS fails, the PoE power budget is
automatically reduced to 370 W for the Summit X450e-48p or X250e-48p switch. PoE port power
management occurs as described in the Power over Ethernet section of the
ExtremeXOS Concepts Guide .
With only a single operating power module, the remaining EPS-600LS behaves as a redundant power
module. The internal power supply is returned to an active state to provide redundant capability.
If both external power modules fail or are disconnected, PoE power is interrupted while transferring
PoE power back to the internal power supply. The internal power supply is then limited to 370 W of
PoE power. The PoE power budget is automatically adjusted accordingly. Power management will occur
as described in the Power over Ethernet section of the
ExtremeXOS Concepts Guide .