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aTCA-80606PA
The system is designed to run indefinitely with any single fan failure. When one fan
fails, all other fans are increased to full speed. The Fan Tray has sufficient cooling
capacity to keep the Shelf cooled with a single fan failure.
6.2.2 Autonomous Mode
When no Shelf Manager is present, the Fans are controlled by the IPM controller. The
fan speed depends on the setting of DIP switch on board. With a Micro DIP switch you
can select either the exhaust temperature from the left Fan Tray or the fixed fan speed
as reference to control the fan speed.
By default the fixed speed of 50% full speed is used to determine the fan
speed. When setting up the DIP switch, “1” stands for on and “0” stands for off.
Table 4: Micro DIP switch settings
Bit1
Bit2
Bit3
Description
0
0
0
Fixed Speed, 50% of Full Speed
0
0
1
Fixed Speed, 70% of Full Speed
0
1
0
Fixed Speed, 90% of Full Speed
0
1
1
Fixed Speed, 100% of Full Speed
1
0
0
Exhaust Temperature 35 ~ 45 °C
1
0
1
Exhaust Temperature 40 ~ 50 °C
1
1
0
Exhaust Temperature 45 ~ 55 °C
1
1
1
Exhaust Temperature 50 ~ 60 °C
Figure 6: Fan Curves
