HP Power over Ethernet (PoE/PoE+) Planning and Implementation Guide

10-3
Planning and Implementation for the HP 3500-PoE Switches
PoE Provisioning
An external power supply, the HP 620 RPS/EPS (J8696A), can be connected
to either of the HP 3500-PoE switches to provide redundant or extra PoE
power. The 620 RPS/EPS can be connected to up to two switches and provide
388 watts of 50V power to each switch.
Table 10-1. PoE Power Provisioning for the 3500-PoE Switches
Note There is a special power provision on the 3500-48-PoE switch where the switch
reserves 22 watts for each bank of 24 ports, ports 1-24 and 25-48, so that neither
set of ports receives the entire 398 watts. This is designed for the integrity and
safety of PoE during power balancing to properly detect PDs and bring them
online.
PoE Allocation Using LLDP Information
You can have the port automatically configure certain PoE link partner devices
if the devices supports advertising of its PoE needs. By enabling PoE LLDP
detection, available information about the power usage of the PD will be used
by the switch to configure the power allocation. The default configuration is
for PoE information to be ignored if detected through LLDP.
For more configuration information, refer to the Management and
Configuration Guide for your switch at www.hp.com/networking/support. Auto
search on “3500”, select your switch model from the list, and click Display
selected. Then click on the links that have “Manuals” in them to get to the web
page that lists the available manuals.
PoE Devices Internal Only Internal and External External Only
PoE for 3500-24-PoE Switch 398 watts available to
ports 1-24.
398 watts available to ports 1-24
(provided by the internal source).
388 watts available as backup in
case of failure, provided by the
external source.
If the internal power supply
has failed, the external
source provides 388 watts to
ports 1-24.
PoE for 3500-48-PoE Switch 398 watts available to
ports 1-48.
786 watts available to ports 1-48
(provided by the internal source).
If the internal power supply
has failed, the external
source provides 388 watts to
ports 1-48. Note that a
minimum of 22 watts will
always be allocated to both
port groups (ports 1-24 and
ports 25-48).