PoE/PoE+ Planning and Implementation Guide 2011-09

2-18
Operating Rules
Provisioning Power for PoE
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 information, see the Management and Configuration Guide for
your switch at www.hp.com/networking/support.
HP ProCurve 3500yl PWR Switches
Maximum PoE Power
The Switch 3500yl-24G-PWR provisions (allocates power to) ports 1-24 with
398 watts of power for PoE applications compatible with the IEEE 802.3af
standard and some pre-standard devices. The Switch 3500yl-48G-PWR
provisions ports 1-48 with 398 watts. This reduces the average per port wattage
by half as compared to the Switch 3500yl-24G-PWR.
An external power supply, the 620 RPS/EPS (J8696A) can be connected to
either of the 3500yl 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 2-10. Maximum Power Allocations for the 3500yl Switches
PoE Devices Internal Only Internal and External External Only
PoE for Switch
3500yl-24G-PWR
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.
The internal power supply has
failed, and the external source
provides 388 watts to ports 1-24.
PoE for Switch
3500yl-48G-PWR
398 watts available to
ports 1-48.
786 watts available to ports 1-48
(provided by both the internal and
external sources).
The internal power supply has
failed, and 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).