Typical values for pd power consumption, Power through the cable – Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) User Manual
Page 590
Power over Ethernet Introduction
Software Reference for x310 Series Switches
22.6
AlliedWare Plus
TM
Operating System - Version 5.4.4C
C613-50046-01 REV A
Once the PSE has detected the PDs IEEE 802.3af or IEEE 802.3at power class, it can manage
the power allocation by subtracting the PDs class maximum value from the overall power
budget. This allows for control and management of power allocation when there is not
enough power available from the PSE to supply maximum power to all ports. Any
unclassified PD is considered to be a class 0 device.
To view the PD class that has been configured for each PoE port, apply the following
command:
Typical Values for PD Power Consumption
The IEEE 802.3af standard specifies the delivery of up to 15.4 watts (W) per port to PoE
devices. This enables a variety of possible devices to make use of the available power. The
maximum power consumed by a PD, as specified by the IEEE 802.3af standard, is 12.95 W.
The system provides the 'extra' power (up to 15.4 W) to compensate for losses in the cable.
Some common PoE device power requirements are:
The IEEE 802.3at standard supports delivery of up to 30 W per port that may be used to
deliver power to PoE+ devices. This allows a variety of possible devices to make use of the
available power. The maximum power consumed by a PD, as specified by the IEEE 802.3at
standard, is 25.5 W. The system provides the 'extra' power (up to 30 W) to compensate for
line loss. Some common PoE+ device power requirements are:
Refer to the LLDP chapters
Chapter 70, LLDP, LLDP-MED and Voice VLAN Introduction
and
for information about power
monitoring at the PD.
Power through the cable:
10/100BASE-TX
Endpoint Mode
The IEEE 802.3af and IEEE 802.3at standards describe two methods for applying PoE over
twisted pair cabling are termed “alternatives A and B”. Alternative A applies power to the
data carrying cable pairs (using pins 1-2 and 3-6). Alternative B applies the power to the
spare cable pairs (using pins 4-5 and 7-8).
The switch uses “alternative A” to apply power to its PDs. An IEEE compliant PD should be
able to receive PoE using either of the two wiring methods.
awplus#
PoE Device
PoE Power Requirement
IP phone
3 W-6 W
Wireless access point
4 W-11 W
IP security camera
5 W-12 W
PoE+ Device
PoE+ Power Requirement
Wireless Access Point
(with LLDP-MED support)
12 W-24 W
Pan Tilt and Zoom
powered IP security
camera
12 W-24 W