Service Manual

GSM-204-523
Replacing a thermal management system (TMS) unit
31st Oct 01
Maint. 3–8
Maintenance Information: Horizon macro outdoor
CONTROLLED INTRODUCTION
68P02902W04-A
Replacing a thermal management system (TMS) unit
Introduction
to TMS
replacement
The TMS units can be replaced while the cabinet is operational, but be aware
that forced air cooling is stopped and cooling is only by natural convection while
the TMS is out of service. This will raise equipment temperature, and could shut
down the cabinet by triggering the temperature sensors.
CAUTION
If the cabinet is operational, this replacement procedure
should be completed without delay, in order to minimize
duration of air cooling disruption.
View of the TMS
unit
Figure 3-4 shows a view of the TMS unit, removed from the cabinet, with upper
panels and air ducts omitted for clarity.
HEATING
ELEMENTS
FAN
ACCESS
PANEL
CONTROL
BOARD COVER
MOUNTING RAIL
ROLLER
Figure 3-4 TMS unit showing major features