PoE/PoE+ Planning and Implementation Guide 2011-09

9-5
Planning and Implementation for the 2910al PoE+ Switches
Planning Your PoE Configuration
The table in this example configuration contains entries that show the PoE+
power available for the 2910al-48G-PoE+ when connecting to an external
power supply.
Figure 9-4. Example of a 2910al-48G-PoE+ Switch connecting to a 630 RPS/EPS
1
The 630 RPS/EPS power supply is rated at 398 watts, however, 388 watts are supplied to the
switch due to line loss on the EPS cable.
The switch can receive redundant power from the 630 RPS/EPS should the
switch’s internal power supply fail.
2910al 48 port
switches
630 RPS/EPS
Source of
Power
Watts
Available
# of Ports Powered and
Average watts/Port
Redundant # of Ports
Powered and Average
watts/Port
Internal PoE+
Power Supply
382 25 @ average 15.4 W each
48 @ average 7.5 W each
48 @ average 4.0 W each
None
Internal plus
External PoE+
power Supply
382 + 388
1
1 - 24 25 - 48
24 @ average 30.0 W each for
a total of 720
48 @ average 15.4 W each
48 @ average 7.5 W each
48 @ average 4.0 W each
24 @ average 30.0 W each for
a total of 360 W
48 @ average 15.4 W each
48 @ average 7.5 W each
48 @ average 4.0 W each
External PoE+
Power Supply
(failed Internal
Power Supply)
388
1
12 @ average 30W each for a
total of 360 W
25 @ average 15.4 W each
48 @ average 7.5 W each
48 @ average 4.0 W each
None