4.8 Fan Box
A fan box consists of a fan tray, four fans, and an FMU.
shows a fan box.
Figure 4-43
Fan box
(1) Fan
(2) Fan tray
(3) FMU
The fan box performs the following functions:
l
Provides forced ventilation and heat dissipation for the cabinet.
l
Monitors the temperature.
l
Supports fan speed adjustment based on temperature or controlled by the BBU.
l
Stops the fans when the ambient temperature is low.
shows the ports on the FMU board.
Figure 4-44
Ports on the FMU board
describes the LEDs on the FMU board.
4 BTS3900 Components
BTS3900
Hardware Description
4-62
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Issue 04 (2011-02-15)