Poe Budget - Allied Telesis AT-IS230-10GP Installation Manual

Chapter 1: Overview

PoE Budget

32
Both IS Series switches have an overall PoE budget. This is the total
wattage the switch has available for all the powered devices connected to
its PoE ports. The maximum PoE power available at any one time is:
AT-IS230-10GP switch - 120W

AT-IS130-10GP switch - 90 W

– 51~57VDC input (IEEE802.3at) 90W
– 45~57VDC input (IEEE802.3af) 61.6W
The PoE budget can never be more than these values on the respective
switches, 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 on the
AT-IS130-6GP switch, power will be delivered to the ports based on the
sequence of being plugged in. In the case of the AT-IS230-10GP switch,
power is delivered to specific ports using a mechanism referred to as port
prioritization - refer to "Port Prioritization" on page 33.
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 will 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
PoE ports of the switch. (See Table 2 on page 31 for the PoE class power
ranges.)