PoE/PoE+ Planning and Implementation Guide 2011-09

13-20
Planning and Implementation for the E5400zl/E8200zl Switches
Configuration Examples
Figure 13-12.Example of a 5412zl with three power supplies, J8712A
In this example (Figure 13-12) there are three power supplies supplying 273
watts each for a maximum of 819 watts.
To achieve the 53 ports at 15.4 watts the PoE devices must be divided up and
connected to three different modules. Remember, as soon as a module is
installed into the switch, 22 watts is reserved for its use.
In this configuration one power supply (273 watts) could be used for
redundant power. However, remember it can only support a limited number
of ports depending on the wattages that are being supplied to the ports.
53 ports can receive up
to 15.4 watts of PoE
273 watts
for PoE
273 watts
for PoE
273 watts
for PoE
Back
Front
5 ports must be used
on this module
Source of Power Watts Available # of Ports Powered and Average watts/
Port
Redundant # of Ports Powered and
Average watts/Port
Three Internal
Power Supplies
(J8712A)
819 (without
redundancy)
53 @ average 15.4 W each
109 @ average 7.5 W each
204 @ average 4.0 W each
17 @ average 15.4 W
36 @ average 7.5 W each
68 @ average 4.0 W each