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

8-2
Planning and Implementation for the HP 2910-PoE+ al Switches
Introduction
For more configuration information, refer to the Management and
Configuration Guide for your switch at www.hp.com/networking/support. Auto
search on “2910”, 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.
Note The dual-personality ports have either auto-sensing 10/100/1000Base-T RJ-45
or SFP connectivity. The SFP ports do not support PoE. If any of the SFP ports
are used, the corresponding RJ-45 port will not be supplied with PoE/PoE+
power.
Power Redundancy for the HP 2910-PoE+ al Switches
The internal power supply in these switches provides both the 12V (RPS) and
54V (EPS) circuits. If the 54V portion of the power supply fails, it will only shut
down the PoE connections. However, if the 12V portion of the power supply
fails, it will shut down the entire switch. Therefore it is important to provide
a redundant power supply for both the 12V and 54V circuits. It is recommended
that both EPS and RPS be connected to provide full redundancy.
HP Redundant/External Power Supplies (RPS/EPS) can be connected to the
HP 2910al Switches for redundant 12 V system power (RPS) and to provide
for additional PoE+ provisioning. For RPS power, the HP 2910-PoE+ al
Switches can be connected to either an HP 620 RPS/EPS (J8696A) or HP 630
RPS/EPS (J9443A). For additional PoE+ EPS power, only the HP 630 can be
used. The HP 620 does not provide 54 V for PoE+, only 50 V for PoE, and the
HP 2910-PoE+ al Switches do not support connections to the HP 620 for EPS.
The HP 2910-PoE+ al Switch provides up to 30W from each port (25.5W for
PD, 4.5W for cable dissipation); the number of ports that can be operated at
full power is limited to 12 ports at full power, and/or 24 ports at 15.4W. To
increase the capacity of the switch, an external power supply can be attached
to double the total system capacity to 24 ports at 30W, or 48 ports at 15.4W.
The power supplies for these switches are optimized to provide the most
efficient and cost effective solution.