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Brocade FastIron X Series Chassis Hardware Installation Guide
53-1001723-02
Managing the cooling system
4
Changing temperature thresholds for thermal planes and fan speeds
The cooling system in the FSX and
FSX 800
include six four-speed fans. The fans operate at speeds
of low, medium-low, medium, and high. In general, each fan speed, except for low, has a low and
high temperature threshold associated with it as shown in
. The low fan speed has a high
temperature threshold only.
FIGURE 38
Fan speeds and temperature thresholds
The low and high temperature thresholds enable the Brocade device to determine at which speed
the fans should operate. In general, the fans operate as follows:
•
If the temperature of all thermal planes is between the low and high thresholds for a fan
speed, the fan continues to operate at that fan speed.
•
If the temperature of any thermal plane exceeds the high threshold specified for a fan speed,
the fan speed increases to the next higher speed. If the temperature of any thermal plane
exceeds the high threshold for the high speed and remains above the threshold for five
minutes, the system automatically shuts down to prevent damage.
•
If the temperature of any thermal plane falls below the low threshold for a fan speed, the fan
decreases its speed to the next lower speed. If the temperature of any thermal plane falls
below the high threshold for the low speed, the fan operates at the low speed.
If the temperature of any thermal plane exceeds the high temperature threshold for any of the fan
speeds, the software sends a message to the system log.
High temperature threshold
(shutdown temperature)
Low temperature threshold
Low temperature threshold
HIGH
MEDIUM
LOW
High temperature threshold
High temperature threshold
MEDIUM-LOW
High temperature threshold
Low temperature threshold