HP ProCurve zl Series User manual

Planning and
Implementation Guide
www.procurve.com
Power over Ethernet (PoE)
for zl and yl Products
PoE
Power over Ethernet Devices

ProCurve Power over Ethernet
(PoE) for zl and yl Products
Planning and Implementation Guide

© Copyright 2005 - 2007 Hewlett-Packard
Development Company, L.P. The information
contained herein is subject to change without notice.
This document contains proprietary information, which is
protected by copyright. No part of this document may be
photocopied, reproduced, or translation into another
language without the prior written consent of Hewlett-
Packard.
Publication Number
5991-6210
February 2007
Applicable Products
Disclaimer
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OF ANY KIND WITH REGARD TO THIS MATERIAL,
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Warranty
See the Customer Support/Warranty booklet included with
the product.
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Hewlett-Packard products and replacement parts can be
obtained from your HP Sales and Service Office or
authorized dealer.
ProCurve Switch 5406zl (J8697A)
ProCurve Switch 5406zl-48G (J8699A)
ProCurve Switch 5412zl (J8698A)
ProCurve Switch 5412zl-96G (J8700A)
ProCurve Switch 3500yl-24G-PWR (J8762A)
ProCurve Switch 3500yl-48G-PWR (J8693A)
ProCurve 620 Redundant and External
Power Supply
(J8696A)
ProCurve Switch zl Power Supply Shelf (J8714A)

iii
Contents
1 Introduction
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Power Through the Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
PoE Capabilities of the Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Power Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
2 Operating Rules
Switch PoE Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Provisioning Power for PoE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Maximum PoE Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
PoE Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Switch Port Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Switch Priority Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Line Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
PD Power Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
PD Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
3 Planning and Implementation for the Series 3500yl
Switches
Planning Your PoE Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
ProCurve 3500yl-24G-PWR Configuration . . . . . . . . . . . . . . . . . . . . . . . 3-2
ProCurve 3500yl-48G-PWR Configuration . . . . . . . . . . . . . . . . . . . . . . . 3-4
4 Planning and Implementation for the Series 5400zl Switch
Planning Your PoE Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
ProCurve 5406zl Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
ProCurve 5406zl Configurations using the Power Supply Shelf 4-10
ProCurve 5412zl Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Standard J8712A Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
Standard J8713A Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Mixed J8712A and J8713A Configurations . . . . . . . . . . . . . . . . . . 4-18

iv
5 Infrastructure Requirements
Air conditioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Power requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Racks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Glossary
A Planning Considerations
General Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
Specific Considerations for the 3500yl Switches . . . . . . . . . . . . . . . . . . . . A-2
Specific Considerations for the 5400zl Switches . . . . . . . . . . . . . . . . . . . . A-3
Index

1-1
Introduction
1
Introduction
This chapter provides an overview of Power over Ethernet (PoE) and a list of
reasons why you might want to implement PoE in your environment. It
discusses how PoE transmits power over twisted pair cable and the
capabilities of the devices used to provide PoE.
Overview
Power over Ethernet technology allows IP telephones, wireless LAN Access
Points and other appliances to receive power as well as data over existing LAN
cabling, without needing to modify the existing Ethernet infrastructure.
Power over Ethernet has become a standard feature of ethernet switches, as
the cost of adding power supplies to the Ethernet switches is small. IEEE
802.3af is an extension to the existing Ethernet standards. It offers the first
truly international standard for power distribution (consider how many
different AC power plugs exist worldwide).
Almost all appliances require both data connectivity and a power supply. Just
as telephones are powered from the telephone exchange through the same
twistedpair that carries the voice, we cannow do the same thing withEthernet
devices.
The technology is bound to make a big impact in the world of embedded
computing. In the realm of embedded computers, where the systems are
increasingly connected to LANs and the internet, the advantages of providing
power and data through a single cable should be obvious. Consider a typical
application: a system for a multi-level car parking garage that includes security
cameras, information signs, call-for-help telephones and vehicle sensors. Such
a system is distributed over a significant area, where main power is not easily
available. A single link to a PoE Ethernet Switch makes implementing this
system less expensive and faster than using a non-PoE switch.

1-2
Introduction
Overview
Introduction
Power over Ethernet connections to embedded computers will allow a less
expensive installation (no AC cabling, lower labor costs), facilitate updating
the installation and repositioning of end devices (wireless access points,
security cameras, and so forth) without electricians, while maintaining full
control over every node through the internet.
Figure 1-1 shows a typical system implemented to power telephones and
wireless access points. The PoE Ethernet switches are installed to supply
power over the twisted pair LAN cables to run phones or other appliances as
required.
Figure 1-1. Example of a Typical Implementation
5406zl Switch
3500yl-48G-PWR 3500yl-24G-PWR
Wireless
Access
Points
Cameras
Cameras
Phones
Phones
Mitel 3300
IP PBX
Wireless
Access
Points
620 RPS/EPS
Power Supply Shelf

1-3
Introduction
Overview
Introduction
Here are some reasons why you might want to do this:
■Simplifies installation and saves space - only one set of wires to bring to
your appliance.
■Saves time and money - there is no need to pay for additional electrical
power runs or to delay your installation schedule to make them.
■Minimal disruption to the workplace - the appliance can be easily moved,
to wherever you can lay a LAN cable.
■Safer - no AC voltages need to be added for additional network devices.
■As well as the data transfer to and from the appliance, you can use SNMP
network management infrastructure to monitor and control the
appliances.
■Appliances can be shut down or reset remotely - no need for a reset button
or power switch.
■When implementing wireless LAN systems it simplifies the radio
frequency (RF) survey task, as the access point can easily be moved and
wired in.
Power Through the Cable
A standard CAT5 Ethernet cable has four twisted pairs, but only two of these
pairs are used for 10Base-T and 100Base-TX data and all four are used for
1000Base-T data. The specification allows two options for using these cables
for power:
■The spare pairs are used. The pair on pins 4 and 5 are connected
together and form the positive supply, and the pair on pins 7 and 8 are
connected and form the negative supply.
■The data pairs are used. Since Ethernet pairs are transformer coupled
at each end, it is possible to apply DC power to the center tap of the
isolation transformer without upsetting the data transfer. In this mode of
operation the pair on pins 1 and 2 and the pair on pins 3 and 6 can be of
either polarity.
The standard does not allow both pairs (spare and data) to be used - a choice
must be made. The Power Sourcing Equipment (PSE) applies power to either
set of wires. ProCurve Networking switches, as a PSE, supply PoE power over
the “data pair” or, pins 1 and 2, and the pair on pins 3 and 6. The Powered
Device (PD) must be able to accept power from both options because mid-
span equipment must (according to the specification) supply power over the
“spare pair” or pins 4 and 5, and the pair on pins 7 and 8.
An obvious requirement of the specification is to prevent damage to existing
Ethernet equipment. A discovery process, run from the PSE, examines the
Ethernet cables, looking for devices that comply with the specification.

1-4
Introduction
Overview
Introduction
It does this by applying a small current-limited voltage to the cable and checks
for the presence of a 25k ohm resistor in the remote device. Only if the resistor
is present, will the full wattage be applied, but this is still current-limited to
prevent damage to cables and equipment in fault conditions.
The PD must continue to draw a minimum current. If it does not (for example,
when the device is unplugged) then the PSE removes the power and the
discovery process begins again.
PoE Capabilities of the Products
The ProCurve PoE switch devices are multiport switches that can be used to
build high-performance switched workgroup networks with PoE. These
switches are store-and-forward devices that offer low latency for high-speed
networking. The ProCurve PoE switch devices are designed to support
Redundant Power Supply and Power over Ethernet (PoE) technologies.
■The ProCurve Switch 3500yl-48G-PWR (J8693A), has 48 Integrated PoE
auto-sensing 10/100/1000Base-T RJ-45 ports with four dual-personality
Gigabit Uplink ports.
■The ProCurve Switch 3500yl-24G-PWR (J8692A), has 24 Integrated PoE
auto-sensing 10/100/1000Base-T RJ-45 ports with four dual-personality
Gigabit Uplink ports.
These switches also support somepre-standard PoE devices. For alist of these
devices, see the FAQs for your switch model. This feature is the default and
you must disable it if you do not want to use it. Refer to the Management and
Configuration Guide which is on the ProCurve Web site, www.procurve.com.
To display the list of downloadable manuals, click on the following links:
Technical support
Product manuals (all)
ProCurve Switch 3500yl or 6200yl Series.
(You may want to bookmark this Web page for easy access in the future.)

1-5
Introduction
Overview
Introduction
For example:
ProCurve 3500yl#(config) no power pre-std-detect
The dual-personality ports have either auto-sensing 10/100/1000Base-T RJ-45,
or mini-GBIC connectivity. The mini-GBIC ports do not support PoE. If any of
the mini-GBIC ports are used the corresponding RJ-45 port will not be supplied
with PoE power.
■The ProCurve Switch 5406zl is a chassis that can hold up to six 24-port
modules to provide up to 144 10/100/1000Base-T RJ-45 ports for PoE
power.
■The ProCurve Switch 5412zl is a chassis that can hold up to twelve 24-port
modules to provide up to 288 10/100/1000Base-T RJ-45 ports for PoE
power.

1-6
Introduction
Overview
Introduction
Power Redundancy
There are two types of power supplied by the Series 5400zl switch power
supplies:
■12V power or system power
■50V power or PoE power
The 12V system power is used for the backplane and is what operates the
internal components of the switch. The 50V PoE power is used to power the
PoE devices connected to the modules.
It is important to provide a secondary power supply for redundancy purposes
for both the 12V and 50V circuits. The internal power supply in these switches
provides both the 12V (system) and 50V (PoE) circuits. If the 12V (system)
power fails the switch will shut down. If the 50V (PoE) fails, all PDs would
lose power. Therefore, to keep the switch running should one power supply,
or either power source fail, you should install a second power supply.
The 5406zl chassis can hold two internal power supplies and the 5412zl chassis
can hold four internal power supplies:
■J8712A, which operates at 100-127 volts and draws 11.5 amps, or 200-240
volts and draws 5.7 amps, and supplies 273 watts of PoE power
■J8713A, which operates at 200-220 volts and draws 10 amps, and supplies
900 watts of PoE power
Using two J8712As, or two J8713As, or a mix of both is supported (however
mixing power supplies is not recommended) and necessary to ensure the
switch has both 12V (system power) and 50V (PoE power) should one power
supply fail. See the ProCurve Switch zl Internal Power Supplies Installation
Guide, for more information and specifications on these power supplies.
When considering redundant power, also consider the power source for the
power supplies. Each power supply should be connected to a separate power
source circuit in order to supply complete redundancy. Should one circuit fail,
it would then be possible for the other circuit to continue supplying power to
the second power supply in the switch, keeping the switch running.
There is also an external power supply, the ProCurve Switch zl Power Supply
Shelf (J8714A), that can be connected to either of the 5400zl switches for the
purpose of adding extra or backup 50V (PoE power). The zl Power Supply
Shelf will not supply any 12V (system power) to a 5400zl switch, since the
switch itself already has full redundancy in it’s 12V sources.

2-1
Operating Rules
2
Operating Rules
This chapter discusses the operating rules and characteristics of the ProCurve
product capabilities. The following products are discussed:
■The ProCurve Switch 3500yl-24G-PWR (J8692A), is used as a PSE device
to provide PoE power to PDs thru the 24 RJ45 ports.
■The ProCurve Switch 3500yl-48G-PWR (J8693A), is used as a PSE device
to provide PoE power to PDs thru the 48 RJ45 ports.
■The ProCurve Switches 5406zl (J8697A) and 5412zl (J8698A), are used as
PSE devices to provide PoE power to the PDs thru the 24 port Gig-T PoE
module (J8702A), or the 20 port Gig-T plus 4 mini-GBIC PoE module
(J8705A).
Switch PoE Operation
The Switch 3500yl-24G-PWR can supply up to 398 Watts of PoE power across
the 24 ports. The Switch 3500yl-48G-PWR can supply up to 398 Watts of PoE
power across the 48 ports.
The Switch 5406zl can supply up to 1800 watts of PoE power and the Switch
5412zl can supply up to 3600 watts of PoE power. It depends on which power
supply is installed. The J8712A power supply provides up to 273 watts of PoE
power. If two J8712As are installed they can supply up to 546 watts of PoE
power and if four are installed they can supply up to 1092 watts of PoE power.
The J8713A power supply provides up to 900 watts of PoE power. If two
J8713As are installed they can supply up to 1800 watts of PoE power and if
four are installed they can supply up to 3600 watts of PoE power. The two
types of power supplies can be mixed (although not recommended), that is,
one or two J8712As and one or two J8713As can be installed at the same time
depending on which of the Series 5400zl Switches are being used.
Note ProCurve Networking highly recommends that the two types of power
supplies are not mixed in the same 5400zl chassis or Power Supply Shelf. See
page 4-9 for more information.

2-2
Operating Rules
Provisioning Power for PoE
Operating Rules
Provisioning Power for PoE
Both the 5400zl and the 3500yl switches support an external power supply that
can provide either redundant or extra PoE power. It is important to understand
how PoE power is provisioned in order to use these external power supplies
efficiently. The following sections will discuss this in detail.
By installing a second power supply in the 5406zl or a third power supply in a
5412zl, depending on how many PoE ports are being supplied with power, the
switch can have redundant power if one power supply fails. A Power Supply
Shelf can also be connected to the 5400zl switches to provide extra or
redundant PoE power.
For example, if the 5406zl has two 24-port PoE modules (J8702A) installed,
and all ports are using 15.4 watts, then the total wattage used is 739.2 watts
(48 x 15.4). Therefore to supply the necessary PoE wattage a J8713A power
supply is installed in one of the power supply slots. Then to gain redundant
power a second J8713A must be installed in the second power supply slot. If
the first power supply fails, then the second power supply can supply all
necessary power.
Threshold - Refer to the Management and Configuration Guide which is on
the ProCurve Web site, www.procurve.com. (See page 1-4.)
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
to each switch.

2-3
Operating Rules
Provisioning Power for PoE
Operating Rules
Table 2-1. Maximum Power Allocations for the 3500yl Switches
Table 2-2. Maximum Power Allocations for the 5400zl 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). See page 2-4.
PoE Devices Internal Only Internal and External External Only
PoE for Switch
5406zl
1 power supply J8712A, 273 watts
2 power supplies J8712A, 546 watts
1 power supply J8713A, 900 watts
2 power supplies J8713A, 1800 watts
2 power supplies one J8712A and one
J8713A
(not recommended),1173 watts
A maximum of 2 internal power
supplies up to 1800 watts and
the external source can provide
up to 1800 watts depending on
which power supplies are
installed.
The internal power supply
has failed, and the external
source provides up to 1800
watts depending on which
power supplies are installed.
Note that without internal
power the switch will not be
active since the EPS does not
supply system power.
PoE for Switch
5412zl
2 power supplies J8712A, 546 watts
2 power supplies J8713A, 1800 watts
2 power supplies, one J8712A and one
J8713A
(not recommended), 1173 watts
3 power supplies J8712A, 819 watts
3 power supplies J8713A, 2700 watts
3 power supplies, one J8712A and two
J8713A
(not recommended), 1446 watts
4 power supplies J8712A, 1092 watts
4 power supplies J8713A, 3600 watts
4 power supplies, two J8712A and two
J8713A
(not recommended), 2346 watts
A maximum of 4 internal power
supplies up to 3600 watts and
the external source can provide
up to 1800 watts depending on
which power supplies are
installed.
The internal power supply
has failed, and the external
source provides up to 1800
watts depending on which
power supplies are installed.
Note that without internal
power the switch will not be
active since the EPS does not
supply system power.

2-4
Operating Rules
Provisioning Power for PoE
Operating Rules
PoE Power
It is important to understand the PoE power requirements of these switches
because if the PoE power is not planned and implemented correctly, end
devices connected to the PoE switch ports may not receive power if a switch
PoE power source failure occurs or if the switch is over provisioned.
The Switch 3500yl-24G-PWR has 24 ports and its internal PoE power supply
provides 398 watts across all 24 ports. The Switch 3500yl-48G-PWR PoE power
requirements are different. This switch has 48 ports and the internal PoE
power supply supplies 398 watts across all 48 ports. 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.
The two PoE modules (J8702A and J8705A) for the 5400zl chassis have the
same requirement for reserving 22 watts. 22 watts per module is always held
in reserve. Therefore each module is always provisioned with at least 22 watts.
Each group of 24 ports is it's own management group and needs to have a
minimum allocation associated with it in order to properly detect PDs and
bring them online.
Remember that each group of 24 ports will have a PoE power allocation of at
least 22 watts. This 22 watts must be subtracted from the total wattage when
figuring how many PoE devices to connect to which ports on a switch or
module. In order to be able to allocate the reserved 22 watts, either use the
ports it is allocated to or the PoE power to all ports on the associated module
must be turned off, refer to the Management and Configuration Guide which
is on the ProCurve Web site, www.procurve.com, for details. (See page 1-4.)
Switch Port Priority
The lower the port number the higher the priority given. For example, port
number one has a higher priority than port number two. Therefore when both
ports need power, port number one is given power priority over port number
two and so on throughout the rest of the ports.
A port can be assigned a power priority that alters the assignment of power
to it by the switch. See the Management and Configuration Guide which is
on the ProCurve Web site, www.procurve.com, for details. (See page 1-4.)

2-5
Operating Rules
Provisioning Power for PoE
Operating Rules
Switch Priority Class
Port priority classification can be used by the switch to allocate power to
ports. It is a prioritization scheme by which the user can assign a low (default),
high, or critical priority to any given port. This assignment is done through
the command line interface (see the Management and Configuration Guide
which is on the ProCurve Web site, www.procurve.com (See page 1-4.)), of
the switch and alters the hardware port-number priority for power allocation.
■Low (default) - This priority class receives power only if all other priority
classes are receiving power. If there is enough power to provision PDs on
only some of the ports with a low priority, then power is allocated to the
ports in ascending order, beginning with the lowest-numbered port in the
class until all available power is in use.
■High - This priority class receives power only if all PDs on ports assigned
with a critical priority are receiving full power. If there is not enough
power to provision PDs on ports assigned with a high priority, then no
power goes to the low priority ports. If there is enough power to provision
PDs on only some of the high priority ports, then power is allocated to the
high priority ports in ascending order, beginning with lowest-numbered
high priority port, until all available power is in use.
■Critical - This priority class is the first to be allocated power. If there is
not enough power to provision PDs on all of the ports configured for this
class, then no power goes to “High or Low” priority ports. If there is
enough power to provision PDs on only some of the critical ports, then
power is allocated to the critical ports in ascending order, beginning with
the lowest-numbered port in the class.
Line Loss
A certain amount of power is consumed by the resistance of the wire in the
LAN cable connected from the switch to the powered device (typically less
than 16% loss), which can be influenced by cable length, quality, and other
factors. The IEEE 802.3af specification has addressed loss of power by
providing more power than a powered device requires. As well, depending
upon the classification (Class 0-3) of the device, the switch will provide more
or less power to address the specific power needs of that end device.

2-6
Operating Rules
Provisioning Power for PoE
Operating Rules
PD Power Classification
A PD is classified based on the maximum power it draws across all input
voltages and operational modes. The most common class is 0, in which the
switch will allow a maximum draw of 15.4 watts per port. As an example, 15.4
watts - Power Loss (16%) = 12.95 watts. See table 2-2.
Table 2-3. Power Usage
As you can see in the table, any 802.3af compliant PD will never require more
than 12.95 watts. The switch provides a minimum of 15.4 watts at the port in
order to guarantee enough power to run a device, after accounting for line loss.
PD Power Requirements
When a PD is initially connected to a PoE port, a minimum of 17 watts of
available power is required to begin the power-up sequence. This 17 watts is
needed to determine the type of PD requesting power (see “PD Power
Classification” on page 2-6). Once the power classification is determined and
power is supplied, any power beyond the maximum power requirements for
that class of PD is available for use.
In the default switch configuration all PoE ports have a Low priority. If the
switch has less than 17 W of PoE power available, the switch transfers power
from lower-priority ports to higher-priority ports.
See “Switch Priority Class” on page 2-5 for information on the use of PoE port
priority classifications. Within each priority class, a lower numbered port is
supplied power before a higher numbered port.
Disconnecting a PD from a port causes the switch to stop providing power to
that port and makes that power available to other ports configured for PoE
operation.
Class Usage Minimum Power Levels
at Output of PSE
Range of Maximum
Power required by
the PD
0 Default 15.4 Watts 0.44 to 12.95 Watts
1 Optional 4.0 Watts 0.44 to 3.84 Watts
2 Optional 7.0 Watts 3.84 to 6.49 Watts
3 Optional 15.4 Watts 6.49 to 12.95 Watts

3-1
Planning and
Implementation for the
Series 3500yl Switches
3
Planning and Implementation for the Series
3500yl Switches
This chapter discusses the planning process a user should follow to
successfully implement PoE using a Series 3500yl Switch.After understanding
what PoE is and its operating rules, the next step to implementation is
planning. See “Specific Considerations for the 3500yl Switches” page A-2, for
an example list of considerations during the planning phase.
Planning Your PoE Configuration
This section assists you in building a PoE configuration. Using the following
examples you can plan, build, and connect PoE devices quickly and easily.
There are four configurations:
■ProCurve Switch 3500yl-24G-PWR
■ProCurve Switch 3500yl-24G-PWR connecting an external power supply.
■ProCurve Switch 3500yl-48G-PWR
■ProCurve Switch 3500yl-48G-PWR connecting an external power supply.
Each example shows a complete configuration. A table shows the PoE power
available to connected PoE devices when using just the switch.
Once you have selected your specific configuration and the PoE power
provided, you then add up the maximum amount of power each device
requires (use maximum power in watts, usually found on a product’s data
sheet). Adjust this total maximum power figure by adding 15% to account for
possible line loss. This value must be less than the maximum power available
shown in the table for your configuration.

3-2
Planning and Implementation for the Series 3500yl Switches
Planning Your PoE Configuration
Planning and
Implementation for the
Series 3500yl Switches
ProCurve 3500yl-24G-PWR Configuration
The table in this example configuration contains entries that show the PoE
power available for the 3500yl-24G-PWR.
Figure 3-1. Example of a 3500yl-24G-PWR Switch
If any of the mini-GBIC ports are used (21-24) the corresponding RJ-45 port
will not be supplied with PoE power. Therefore that needs to be taken into
consideration when planning per port PoE wattage.
If for example, port 24 is used for a mini-GBIC, then the RJ45-port 24 is
disabled. Therefore the PoE power that was being supplied to the RJ45-port
24 is returned to the total available pool of PoE power.
All 24 ports can receive up to 15.4
watts of PoE power
Source of
Power
Watts
Available
# of Ports Powered and
Average Watts/Port
Redundant # of Ports
Powered and Average Watts/
Port
Internal PoE
Power
Supply
398 24 @ average 15.4 W each for
a total of 369.6 W
None