User's Manual

Table Of Contents
ADCP-75-348 • Issue 1 • 04/2008
Page 28
© 2008, ADC Telecommunications, Inc.
Figure 20. Host Unit Card Locations
7.1 Host Unit Fan Replacement Procedure
The HU is equipped with a fan assembly consisting of two cooling fans which is located on the
left side of the HU enclosure. The cooling fans blow cool air into the enclosure. Heated air is
exhausted through the vent openings on the right side of the enclosure. Replacement of fan
assembly does not require that the HU be turned off. The recommended replacement interval is
60 months. Use the following procedure to remove and replace the HU cooling fans:
1. Before working on the HU or handling a fan, slip on an Electro-Static Discharge (ESD)
wrist strap and connect the ground wire to an earth ground source. Wear the ESD wrist
strap while completing each section of the fan installation procedure.
2. Notify the NOC or alarm monitoring system operator that the fan is being replaced.
3. Loosen the two thumb screws that secure the fan/grill assembly to the front of the HU
enclosure as shown in
Figure 21.
4. Carefully withdraw the fan/grill assembly from the enclosure.
5. Slide the new fan assembly into the HU chassis until it is firmly seated.
6. Secure the fan/grill assembly to the front of the enclosure (see Figure 21) using the two
screws loosened in Step 3.
7. Verify that the fans run properly following power-up.
8. Notify the NOC or alarm monitoring system operator that the fans are back in operation.
Warning: Electronic components can be damaged by static electrical discharge. To prevent
ESD damage, always wear an ESD wrist strap when working on the HU and when handling
electronic components.
SeRF CARD
SYSTEM CARD
POWER SUPPLY
DART CARD
DART CARD
DART CARD
DART CARD
DART CARD
DART CARD
DART CARD
DART CARD
FAN ASSEMBLY
22402-A