7450 ESS-7 Overview
7450 ESS-7 Page 31
FAN TRAYS
The 7450 ESS-7 system is cooled by either a dual-tray system that houses two fans on each tray
(Figure 9) or a single high flow fan tray that houses four fans (Figure 10). Air is pulled through the
system from a left-side filtered-intake vent, across the line cards and then exits through the two
rear fan trays. The AC PSM intakes air through the front of the unit and exhausts out the back. The
fan rate is reduced at normal temperatures and increases to high speed when the operating
temperature rises above 68° C (154° F). When the temperature drops to 50° C (122° F) the fans
return to the half speed rate.
The fan LED located on the front panel of the chassis indicates normal online (green), fault
(amber), or offline (not lit) if there is no power to the fans.
NOTE: There are three temperature sensors per IOM and SF/CPM and one temperature sensor per
MDA. The highest temperature from any sensor is reported as the temperature for that slot. If the
fan LED is lit amber (which indicates a fan problem), use the show card 1 detail CLI
command to monitor the current temperature and temperature threshold fields. If the
temperature rises quickly and remains above the temperature threshold, an alarm is generated.
Repair or replace the unit immediately.
The cooling system components work together to keep the internal components within the
acceptable temperature range. The cooling system consists of the following components:
• One fan tray with four fans (single fan tray) or
two fan trays each housing 2 fans
•One air filter
• Chassis left-side air intake
• Rear air outlet
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