Technical data

Power supply/fan assembly LEDs
Each power supply/fan assembly has one LED.
The LED is illuminated when both the power supply and the fan are operational. When a power supply
or fan fault occ
urs, the LED goes off. If the LED is off, AC power is not present or there is a complete
power supply f
ailure.
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The power-supply-mounted fans cool the chassis by circulating air through the enclosure. The rate at
which air moves (the airflow) determines the amount of cooling. This airflow is a function of fan speed
(rpm). These fans, under the control of the Environmental Monitoring Unit (EMU) or the associated power
supply, c
an operate at multiple speeds. This ensures that when the enclosure temperature changes, the
fans can a
utomatically adjust the airflow. If one fan operates too slowly or completely shuts off, the
other fan operates at a higher speed. At the same time, the error condition is reported to the user
via the LCD panel on the front of the controller.
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System components and LEDs