Installation Guide

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.
Dual 750 W PoE PSUs Configuration: Full Power
Two 750 W PoE PSUs provide full power at 760 watts; this power level allows 15.4 watts 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 750 W PoE PSUs Configuration: Full Redundant Power
Three 750 W PoE PSUs provide the full 760 watts of power for 15.4 watts of PoE power to all 48 ports.
In addition, this configuration provides 2:1 redundancy. If one of the 750 W PoE PSU fails, the third
power module continues to provide uninterrupted full PoE power. The internal power supply of the
switch is disabled in this configuration.
For information on installing the EPS-C2, see Installing an EPS-C2 Power Supply on page 225.
Each EPS-C2 power supply is shipped with a special redundant power supply cord.
Figure 97: EPS-C2 2x7 Pin Redundant Power Cable
Power Supplies for Use with Your Switch
ExtremeSwitching and Summit Switches: Hardware Installation Guide 97