Fan Speed Control Voltage; Speaker; I 2 C Bus; Fan Speed Control - Intel AC450NX Product Manual

AC450NX Rack Server System Product Guide

Fan Speed Control Voltage

The server fans operate at two speeds: slow and fast. The low voltage setting allows the fans to
run at a slower speed to minimize acoustic noise under normal conditions. When the Front Panel
Controller (FPC) senses a fan failure or the ambient air temperature sensor reads 30 °C or higher, it
sets the fan voltage to high to increase the fan speed. The ambient air temperature must drop to
28 °C or the failing condition must be cleared before the FPC returns the fans to slow speed again.
When the ambient air temperature reads between 28 °C and 30 °C, the fans remain at their current
speed.
Table 23-1. Fan Speed Control
Fan Failure
No
Yes
No
Yes

Speaker

Either the FPC or the PHP I/O baseboard can control the speaker on the front panel board.
I 2 C Bus
2
The private I C bus monitors failures and voltage margining in the server. The 5 V standby
voltage provides power for the bus, and it is available even when server power is off.
White text
278
Ambient Air Temperature
<28°C
<28°C
>30°C
>30°C
Fan Speed Voltage
Slow Low
Fast High
Fast High
Fast High