PoE/PoE+ Planning and Implementation Guide 2011-09

13-22
Planning and Implementation for the E5400zl/E8200zl Switches
Configuration Examples
Standard J8713A Configurations
Figure 13-14.Example of a 5412zl with two power supplies, J8713A
This configuration (Figure 13-14) is an example of two power supplies
supplying 900 watts each for a maximum of 1800 watts to a fully loaded chassis
of 288 ports. Therefore out of the total 288 available ports, 116 can be powered
at 15.4 watts each. That’s equal to a little over 4 modules, or all ports could be
used at 4.0 watts.
55 ports could be provisioned at 15.4 watts using 847 watts of the total 1800
leaving 953 watts. Then provision the other 238 ports at 4 watts using 952 watts
of the remaining 953 watts. Finally leaving 1 watt.
This configuration could be redundant for PoE power up to 900 W. The upper
6 slots would stay up if they were the ports suppling the PoE power and the
lower 6 slots were used for other than PoE power. One power supply has
enough power to supply system power to the upper 6 slots and keep the switch
up and running. And as long as the 900 watts of PoE power is not exceeded,
then the top 6 modules would remain powered.
Back
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
240 @ average 7.5 W each
288 @ average 4.0 W each
None