Features
21
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 with one fan failed (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 LS Module 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 is failed. The following table shows
how the fan speed relates to temperature change.
Note: All fans in an enclosure are set to the same speed.
Table 1-1 Fan Speed vs. Temperature Change
ACM Speed Ambient Temp (oC)
Speed 1 0 to 26
Speed 2 26 to 28
Speed 3 28 to 30
Full Speed 30 +