PoE/PoE+ Planning and Implementation Guide 2011-09

7-5
Planning and Implementation for the E2620 PoE+ Switches
Planning Your PoE Configuration
Figure 7-4. Example of a E2620-48-PoE+ Switch
For example, the switch starts with 364 watts. It takes 360.0 watts to fully
provision 12 ports at 30 watts per port (plus 4 watts to account for load
fluctuations), leaving the pool of available watts empty.
Since a port requires 33 watts to power up a PoE+ device, there is not enough
available power to power another device.
The table in this example configuration contains entries that show the PoE+
power available for the E2620-48-PoE+ when connecting to an external power
supply.
Figure 7-5. Example of a E2620-48-PoE+ Switch connecting to a 630 RPS/EPS
All 24 ports can receive up to 15.4
watts of PoE power
or
48 ports can receive up to 7.5
watts of PoE power
12 ports can receive up to 30
watts of PoE+ power
or
Source of
Power
Watts
Available
# of Ports Powered and
Average watts/Port
Redundant # of Ports
Powered and Average watts/
Port
Internal PoE+
Power
Supply
364 12 @ average 30 W each
24 @ average 15.4 W each
48 @ average 7.5 W each
48 @ average 4.0 W each
None
E2620 48 port switch
630 RPS/EPS