Poe Connection Guidelines; Poe Budget - Allied Telesis IS Series Installation Manual

PoE Connection
Guidelines

PoE Budget

Here are guidelines for connecting different types of powered devices
(PDs) on the PoE switch ports:
PoE or PoE+ devices that comply with the IEEE 802.3af and

802.3at standards support Alternatives A and can be connected to
any of the twisted-pair ports 1 - 8.
PoE or PoE+ devices that do not comply with the standards and

only support Alternative A can also be connected to any of the
twisted-pair ports 1 - 8.
Non-PoE devices can be connected to any of the twisted-pair ports

on the switch. Ports connected to network nodes that are not PDs
(that is, devices that receive power from another power source)
function as regular Ethernet ports, without power being delivered to
the device. The PoE feature remains enabled on the ports but no
power is delivered to the devices.
Note
Alternative B method of delivering PoE power (over strands 4, 5, 7
and 8) is not supported.
The IS230-10GP switch has a PoE budget. This is the total wattage the
switch has available for all the powered devices connected to its ports.
The maximum possible PoE power available at any one time is 120W. The
PoE budget can never be more than that, but it can be less, depending on
the maximum power rating of the DC power supply.
The number of powered devices the switch can support at one time
depends on the switch's PoE budget and the wattage requirements of the
powered devices. As long as the total wattage requirements of all the
powered devices is less than the budget of the switch, the switch can
supply power to all the devices. If the total wattage requirements exceed
the PoE budget, the switch will deny power to one or more devices using a
mechanism referred to as port prioritization.
To determine whether the wattage requirements of the PoE devices you
plan to connect to the switch exceed its budget, refer to their
documentation for their power requirements and add the requirements
together. The switch should be able to power all the devices
simultaneously as long as the total is below its PoE budget. If the total
exceeds the available power budget, you should consider reducing the
number of PoE devices so that all the devices receive power.
The switch can handle different power requirements on different ports.
This enables you to connect different classes of PoE equipment to the
ports on the switch. (See Table 4 on page 26 for the PoE class power
ranges.)
IS230-10GP Industrial Ethernet Layer 2 Switch Installation Guide
27