Installation Manual

Table Of Contents
Release 3.3, Revision A 1/99
BTS Field Maintenance 121
A2-1.7 Replacing fan assemblies
This section contains the procedures for replacing fan assembly units on the WAVEXpress/BTS. Refer to Figure A3-1
for an illustration of the replacement position.
There are two types of fan assemblies on the WAVEXpress/BTS: power supply fan and cabinet fan. The power supply
fan provides air flow to the power supply units and is located in the bottom-right-hand corner of the chassis, next to
the optional power supply unit and below the clock module. The cabinet fan provides air flow to the cards and modules
enclosed in the chassis and is located at the top of the chassis above the card slots.
If there is a fan failure, the OMC will display a “Shelf Fan Failure” alarm but will not distinguish whether the failure is at
the power supply fan or the cabinet fan. The BSS maintenance engineer thus need to check both fans in order to find
out which fan is not rotating properly.
Replacing the power supply fan
Step 1
Ensure that anti-static precautions are taken.
Step 2
Using a Phillips screwdriver, unscrew the screw located at the top of the power supply fan.
Step 3
Pull out the power supply fan.
Step 4
Place the new power supply fan into the appropriate slot in the chassis (refer to Figure A3-1) and slide
in the unit until it completely rests inside the slot. Push the fan firmly into place and make sure that the
end connectors meet.
Step 5
Using a Phillips screwdriver, screw in the removed screw onto the power supply fan.
Step 6
Verify that the fan is rotating properly.
Step 7
Inform the OMC operator to verify that all relevant alarms have cleared.
NOTE
Only one of the following procedures should be completed if a “Shelf Fan Failure”
alarm is displayed at the OMC. These procedures can be completed while the
WAVEXpress/BTS is on-line and operational. Calls will not be interrupted or dropped
during the process.