Allied Telesis AT-S62 - Manual (Page 68)

Chapter 3: Basic Switch Commands
68 Section I: Basic Operations
SET SYSTEM FANCONTROL
Syntax
set system fancontrol=on|off|enable|disable
Parameter
fancontrol Activates and deactivates fan control. Options are:
on or enable Activates fan control.
off or disable Deactivates fan control. This is the
default setting.
Description
Note
This command only applies to the AT-8524POE switch.
The AT-8524POE switch has a fan control feature that automatically
adjusts the speed of four of its five cooling fans based on the ambient
temperature of the room or wiring closet where the unit is installed and the
load requirements of the PoE devices connected to the ports on the
device. The lower the ambient temperature and load requirements of the
powered devices, the lower the fan speed required by the system to
maintain proper cooling.
The purpose of this feature is to decrease fan noise from the unit by taking
advantage of building and networking environments where a reduction in
fan speed will not compromise system cooling. A decrease in fan noise
can lessen the chance of the switch being an annoyance to individuals
when the device is installed in a public or work area.
When the fan control feature is deactivated, the default setting, the cooling
fans operate at maximum speed at all times. When activated, fan speeds
are continuously adjusted according to the ambient temperature as
measured at the point where the air enters the cooling vents on the side of
the switch, and the current load requirement of the PoE devices.
The four cooling fans controlled by this feature operate as a unit and have
an operating range of approximately 5,000 to 11,000 RPM. The fans are
operated at full speed when the ambient temperature reaches 40° C (104°
F) or the PoE load exceeds 8.5 amps.
If a fan in a switch fails when the fan control feature is activated, the switch
proportionally increases the speed of the remaining operational fans to
compensate for the loss of the failed fan.