11-10
Power Over Ethernet (PoE) Operation
General PoE Operation
Determining the Amount of PoE Power Available
Table 11-1 shows the amount of PoE power available for powering PDs
depending on the power supplies used.
Table 11-1. PoE Power Available
Power Priority Operation
When Is Power Allocation Prioritized?
If a PSE can provide power for all connected PD demand, it does not use its
power priority settings to allocate power. However, if the PD power demand
oversubscribes the available power, then the power allocation is prioritized
to the ports that present a PD power demand. This causes the loss of power
from one or more lower-priority ports to meet the power demand on other,
Source of Power
PoE Power Available
PoE Power Available for
the
PoE (J8702A)
Module
One power supply
J8712A Power Supply=273 watts
J8713A Power Supply=900 watts
Depending on the power
demand from the PDs, lower
priority ports may not be
provisioned. Refer to
“Calculating the Maximum
Load for a PoE Module” on
page 11-34.
Two power supplies of
the same type
(recommended)
Two J8712A Power Supplies=546
watts
or
Two J8713A Power Supplies=1800
watts
Two power supplies of
different types (not
recommended)
One J8712A power one
J8713 power supply=1173 watts
Three power supplies
Three J8712A power supplies=819
watts
Three J8713A power
supplies=2700 watts
One J8712A and two J8713A=1446
watts
Four power supplies
Four J8712A power supplies=1092
watts
Four J8713A power supplies=3600
watts
Two J8712A and two J8713A
power supplies=2346 watts
3500-5400-6200-8200-MCG-Jan08-K_13_01.book Page 10 Monday, January 28, 2008 10:04 AM