Figure 187: Mts 2 Airflow - Motorola MTS LiTE Installation, Configuration And Basic Service Manual

6802800U74-AN
Chapter 12: Cooling Fans

Figure 187: MTS 2 Airflow

MTS 4:
In MTS 4 the airflow is different. The additional depth and width of the cabinet are used to guide and
separate ambient air intake and heated air outlet. For both card cages the main airflow of ambient air
enters at the front. At the bottom card cage the air can enter from all sides. For the top card cage the
air has to pass in front of and behind the bottom card cage. In the front, between the modules and the
cabinet door. In the back, between the bottom card cage back and the back of the cabinet. The flow is
obstructed by an insert which guides the hot air from the bottom card cage out to the sides and up
between the top card cage and the cabinet sides. The exhaust from the top card cage could be partly
obstructed by a Cavity Combiner situated above. The exhaust can occur on all sides. No obstructions
are inserted. Due to the obstructions in the airflow, fans are required for all configurations of MTS 4.
The fans have a low rpm alarm indication. Each fan module (part no. WALN4381) has two fans inside.
In case of failure, one of the fans still gives an airflow. Therefore the fan module is not considered a
periodic maintenance component, but is only replaced when it fails.
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Air exhaust
top and sides
Heated
air flow
around filters
Air intake all sides