Extreme Networks Summit X150 Series Hardware Installation Manual page 128

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.
Disconnect the EPS-C/EPS-600LS
To manually disconnect an EPS-C or to remove the EPS-600LS modules, the recommended practice is
to disconnect the EPS-600LS modules one at a time, pausing two seconds after each EPS-600LS
disconnect.
This enables a graceful power transition from the external power supplies to the internal power supply.
Example: Two active EPS-600LS modules in an EPS-C
1 Unplug one EPS-600LS unit from its power source.
PoE power is automatically reduced to 370 watts and the internal switch power supply is enabled,
providing redundant 370 watt PoE power.
2 Wait at least two seconds before disconnecting the remaining EPS-600LS unit.
Summit Family Hardware Installation Guide
Summit Power Supplies
128