Chassis Cooling - Avaya 8800 Planning And Engineering

Chassis cooling

You can use two basic methods to determine the cooling capacity required to cool the switch.
You can use the Avaya Power Supply Calculator Tool to determine power draw in watts, or you
can use a worse-case power draw.
You can use the Avaya Power Supply Calculator Tool to determine the power draw for a chassis
configuration. Use this power draw in the following cooling capacity formula:
Cooling capacity (BTU) = power draw (W) x 3.412
The chassis configuration can affect the switch cooling requirements. If you change the switch
configuration, the cooling requirements can also change.
The alternative method is to determine a worse-case power draw on the power supply, and
then use this value in the cooling capacity formula.
When using the second method, take into consideration the number of power supplies and
redundancy. The worse-case power draw is the maximum power draw plus the number of
supplies required to operate the system without redundancy.
For example, if two 8005AC power supplies power a chassis, and a third is added for
redundancy, the worse-case value is the maximum power draw of a single 8005AC power
supply times two (the total of two power supplies, not three). For the 8005AC power supplies,
the actual draw depends on the input voltage. For a nominal input voltage of 110 VAC, the
draw is 1140 watts (W). For 220 AC volts (VAC), the draw is 1462 W. For a three-power supply
system running at 110 VAC, the maximum worse-case power draw is 1140 W x 2, or 2280 W.
Therefore this system requires a cooling capacity of 7164 British thermal units (BTU).
You also need to consider the cooling requirements of the power supplies themselves. For
more information about these specifications, see Avaya Ethernet Routing Switch 8800/8600
Installation — AC Power Supply, NN46205-306 and Avaya Ethernet Routing Switch 8800/8600
Installation — DC Power Supply, NN46205-307. Add these values to the cooling capacity
calculation. For a multiple power supply system, you need to factor into the calculation the
maximum nonredundant number of power supplies.
You must also consider the type of module installed on the chassis. If you install an RS module
in the chassis, you must install the high speed cooling modules. If you do not install the high
speed cooling modules, the software cannot operate on the RS module. For information about
installing high speed cooling modules, see Avaya Ethernet Routing Switch 8800/8600
Installation — Cooling Module, NN46205-302.
Design a cooling system with a cooling capacity slightly greater than that calculated to maintain
a safe margin for error and to allow for future growth.
Planning and Engineering — Network Design
Chassis considerations
November 2010 21