PoE/PoE+ Planning and Implementation Guide 2011-09

12-4
Planning and Implementation for the E3800 Switches
Planning Your PoE or PoE+ Configuration
The table in this example configuration contains entries that show the PoE
power available for the E3800-24G-PoE+-2SFP+ or E3800-24G-PoE+-2XG
Switch when two power supplies are installed.
Figure 12-2. Example of the E3800-24G-PoE+-2SFP+ or E3800-24G-PoE+-2XG Switch
with two power supplies installed
Two power supplies can be installed in the E3800-24G-PoE+-2SFP+ or E3800-
24G-PoE+-2XG Switch to add more PoE/PoE+ power or to provide backup
power should one of the power supplies fail.
For example, if there are two 1000 watt power supplies installed, wattage from
one of the power supplies can be used to supply PoE/PoE+ power to the ports
and the other power supply can be held in reserve. Should the first power
supply fail the reserve power supply can pick up the load and supply the
needed PoE/PoE+ power. Or, both power supplies can be used to supply a
maximum wattage of PoE/PoE+ power.
All 24 ports can supply up to 30
watts of PoE+ power or 15.4 watts
of PoE power
Source of
Power
Watts Available # of Ports Powered and
Average watts/Port from
internal supply
Redundant # of Ports
Powered and Average
watts/Port
Two 1000 watt
Power Supplies
127 W for
system use, and
573 W + 700 W
(for a max of 720
W) for PoE+ @
110 V
24 @ average 30 W each for
a total of 720 W
24 @ average 15.4 W each
24 @ average 7.5 W each
19 @ average 30 W
each for a total of
570 W
Two 1000 watt
Power Supplies
127 W for
system use, and
873 W + 1000 W
(for a max of 720
W) for PoE+ @
220 V
24 @ average 30 W each for
a total of 720 W
24 @ average 15.4 W each
24 @ average 7.5 W each
24 @ average 30 W
each for a total of
720 W