EX9204 Cooling System
The cooling system in an EX9204 switch consists of a fan tray and an air filter. The cooling system components work together to keep all switch components within the acceptable temperature range.
Fan Tray
The fan tray is a hot-insertable and hot-removable field-replaceable unit (FRU) and contains three fans. The fan tray and air filter install vertically in the rear of the switch. See Figure 1 and Figure 2.
Airflow Direction in the EX9204 Switch Chassis
The air intake to cool the chassis is located on the side of the chassis next to the air filter. Air is pulled through the chassis toward the fan tray, where it is exhausted out through the side of the chassis. The air intake to cool the power supplies is located in the front of the chassis above the craft interface. See Figure 3.
The host subsystem monitors the temperature of switch components. Under normal operating conditions, the fans in the fan tray run at less than full speed. If a fan fails or the ambient temperature rises above a threshold, the speed of the remaining fans is automatically adjusted to keep the temperature within the acceptable range. If the ambient maximum temperature specification is exceeded and the system cannot be adequately cooled, the Routing Engine shuts down the system by disabling output power from each power supply.
You cannot replace a single fan. If one or more fans fail, you must replace the entire fan tray.