Installation Guide

The EPS-C2 system provides redundant power for up to five switches. Redundant power connectors on
the rear panel of the EPS-C2 chassis are specific to the supported switch type; a selection switch
toggles between the connector type.
The 750 W AC PoE PSU used on the EPS-C2 has two power rails: 12V and PoE. These two power rails
are independent. If the PoE rail overloads, it will shut down all PoE but the 12V rail will continue to
function. If the 12V rail overloads, the 12V shuts down and the PoE rail will continue to function.
The following table lists the power capability in watts of the EPS-C2 based on the number of installed
PSUs. Check the power requirements of your switches to determine how many PSUs you need to install
into the EPS-C2 chassis.
12V Power (W) PoE Power (W)
1 PSU 300 380
2 PSUs 600 760
3 PSUs 900 1140
For technical specifications, see EPS-C2 Redundant Power Supply Technical Specifications on page 466.
EPS-C2 connectors
The EPS-C2 delivers power in the following ways.
2x7 connector
The 2x7 connector is compatible with ExtremeSwitching X440-G2 and X620 switches. Using the 2x7
connector, the EPS-C2 provides redundant PoE power at the same level no matter how many PSUs are
installed. That is, if there are one, two, or three PSUs installed into the EPS-C2, the EPS-C2 will provide
redundant PoE power capability at the same 380-watt capacity as the internal power supply of the
connected switches. The PoE power supplied does not increase more than 380-watt even if additional
PSUs are installed.
Internal-to-External Power Supply Transfer
When a EPS-C2 is connected to the switch and the internal power supply fails, power is drawn from the
EPS-C2 without power interruption to the switch or PoE connected devices.
External-to-Internal Power Supply Transfer
When a EPS-C2 is connected to the switch and the EPS-C2 fails or is disconnected, power is drawn from
the internal power supply without interruption to the switch or PoE connected devices.
Single 750 W PoE PSU Configuration: Redundant PoE Power
A single 750 W PoE PSU provides redundant PoE power capability up to a 380-watt maximum capacity.
This is sucient to supply up to 15.4 watts per port for a 24-port configuration and up to 7.7 watts per
port for a 48-port configuration.
If the internal power supply fails, the external power module will provide power to the switch and PoE
devices at the same power levels as the internal power supply without any power interruptions.
If the 750 W PoE PSU fails or is removed, the internal power supply of the switch continues to provide
PoE power without any power interruptions.
Power Supplies for Use with Your Switch
EPS-C2 Redundant Power System
ExtremeSwitching Hardware Installation Guide 123