Installation guide

EPS-600LS External Power Module
Summit Family Switches Hardware Installation Guide
49
The PoE capability of the Summit X450e-48p or X250e-48p varies depending on the number of external
power modules in use. Table 11 summarizes the PoE power behavior for the Summit X450e-48p or
X250e-48p switch based on the number of power modules in use.
Single 600-LS Module Configuration: Redundant PoE Power
A single EPS-600LS power module provides redundant PoE power capability with the same 370-watt
capacity as the internal power supply. The internal Summit X450e-48p or X250e-48p power supply is
capable of 370 W of PoE power: 15.4 W supplied to each port for a 24-port configuration and 7.7 W
supplied to each port for a 48-port configuration.
● If the internal power supply fails, the external power module will provide power to PoE devices at
the same power levels as the internal power supply without any power interruptions.
● If the EPS-600LS power module fails or is removed, the internal power supply continues to provide
PoE power without any power interruptions.
Dual 600-LS Module Configuration: Full Power
Two EPS-600LS power modules provide full power at 740 W, which allows 15.4 W of PoE power to all
48 ports. In this full-power configuration, the internal power supply is disabled, and therefore
redundant power is not available.
Triple 600-LS Module Configuration: Full Redundant Power
Three EPS-600LS power modules provide the full 740 W of power for 15.4 W of PoE power to all 48
ports. In addition, this configuration provides 2:1 redundancy. Should one of the EPS-600LS power
modules fail, the third power module continues to provide uninterrupted full PoE power. The internal
power supply is disabled in this configuration.
Internal-to-External PSU 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 PSU 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 PSU fails, power is drawn from the EPS-
600LS without power interruption to the PoE connected devices.
Table 11: External Power Modules and Corresponding PoE Behavior
Internal PSU
Status
EPS-600LS (1x) EPS-600LS (2x) EPS-600LS (3x)
External PSU/Chassis
Failed/Disconnected
Internal PSU:
Power On
370 W of
redundant power
740 W of
external power only
Internal PSU disabled
740 W of
external power only
with 2 + 1 redundancy
Internal PSU disabled
370 W of
internal power only
Internal PSU:
Power Failure
370 W of
external power only
740 W of
external power only
740 W of
external power only
with 2 + 1 redundancy
No PoE power