Huawei ATN 950B - System Air Channel; FAN - Fan Board; Overview; Functions and Features

3.1 System Air Channel
ATN 950B dissipates heat by blowing air in a left-to-right direction.
Figure 3-1 shows the system air channel.
Figure 3-1 Air flow in the ATN 950B
3.2 FAN - Fan Board
This section describes the AND1FAN, a fan board, in terms of the overview, functions, features,
working principle, front panel, and technical specifications.
3.2.1 Overview
The AND1FAN (FAN for short) is an FAN board. The function version of the FAN is AND1.
The FAN is housed in slot 11.
3.2.2 Functions and Features
The FAN is used to adjust the fan rotating speed, detect and report status of fans.
The functions and features of the FAN are as follows:
l Accesses two 12 V power supplies for driving six fans.
l Provides start-delay for the power supply of the fans, protects fans against overcurrent, and
filters the lower frequency.
l Intelligently adjusts the rotating speed of fans to ensure proper heat dissipation of the
system.
l Reports information about the fan rotating speed, environment temperature, alarms, version
number, and board in-position information.
l Provides alarm indicators.
3.2.3 Working Principle and Signal Flow
The FAN mainly consists of the combiner/start-delay module, filter module, communication
unit module, intelligent fan speed adjustment module, and board in-position module.
Figure 3-2 shows the block diagram for the working principle of the FAN.
ATN 950B Multi-service Access Equipment
Hardware Description 3 Heat Dissipation System
Issue 03 (2012-07-23) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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