PoE/PoE+ Planning and Implementation Guide 2011-09

13-12
Planning and Implementation for the E5400zl/E8200zl Switches
Configuration Examples
Figure 13-5. Example of a 5406zl with two power supplies, J8713A
This configuration (Figure 13-5) is an example of two power supplies
supplying 900 watts each for a maximum of 1800 watts to a fully loaded chassis
of 144 ports. Therefore out of the total 144 available ports, 116 can be powered
at 15.4 watts each.
Alternatively, one power supply could be used to supply PoE power at 900
watts and the other power supply could be used as a secondary power supply.
If both power supplies are connected to different power sources, one could
backup the other in case of failure. With this option the user must manage the
PoE usage in order to maintain redundancy.
In this example the threshold command could be set at 50%, and if the switch
begins to use more than 900 watts an event message would be logged, allowing
you to adjust the PoE load or add a Power Supply Shelf for additional power
as required to obtain the best power balance for your operation.
Connecting a fully loaded external power supply can double the available PoE
power. See page 13-14.
Power Supply
J8713A
Front
900 watts
for PoE
900 watts
for PoE
Source of Power Watts Available # of Ports Powered and Average
watts/Port
Redundant # of Ports Powered and
Average watts/Port
Two Internal PoE
Power Supplies
(J8713A)
1800 (without
redundancy)
116 @ average 15.4 W each
144 @ average 7.5 W each
144 @ average 4.0 W each
58 @ average 15.4 W each
116 @ average 7.5 W each
144 @ average 4.0 W each
Two External
Power Supplies
(J8713A)
Additional 1800 144 @ average 15.4 W each
144 @ average 7.5 W each
144 @ average 4.0 W each
116 @ average 15.4 W each
144 @ average 7.5 W each
144 @ average 4.0 W each