Acer altos s300

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 1 Introduction
6
Cooling system
Cooling is provided by the two Advanced Cooling Modules (ACMs) 
located at the rear of the enclosure.  Each of the ACM units contain 
two variable speed fans.  The enclosure requires four fans for normal 
operation, but will operate correctly when one fan fails to function 
(redundancy is lost if one fan is failed in either ACM), however, it is 
recommended that the failed fan be replaced as soon as possible.  The 
ACM units can be hot swapped.  The I/O Option Module (ESM and TSM 
described later) monitors and controls the speed of each fan.  The 
speed is set depending on the ambient temperature and failed status.  
The fans are set to full speed, if one fan fails to function.  
The following table shows how the fan speed relates to temperature 
change.
Note:  All fans are set to the same speed.
ACM Speed
Ambient Temp ( 
o
C
)
Speed 1
0 to 26
Speed 2
26 to 28
Speed 3
28 to 30
Full Speed
30 +
1
2
1
2
0
I
0
I
Mute
ACMs
Fans 1 & 2
Fans 3 & 4