Cooling System and Airflow in ACX7332 Routers

SUMMARY Learn about the cooling system components in ACX7332 Routers.

The cooling system components work together to keep all router components within the acceptable temperature range.

When the router is operating normally, the fans function at lower 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 maximum temperature specification is exceeded and the system cannot be adequately cooled, the router shuts down some or all of the hardware components.

The cooling system consists of the following components:

Fan Trays
Airflow
Power Supply Cooling System

Fan Trays

The ACX7332 router has four hot-insertable and hot-removable field-replaceable fan trays that sit at the rear of the router (See Figure 1). Each fan tray contains two fans.

Figure 1: Fan Tray

Fan tray ejector lever

Note:

The ACX7332 router must operate with all the four fan trays installed. If you need to replace a faulty fan tray, you must replace the fan tray within three minutes.

Fan Status LEDs

Each fan has one bicolor LED. The fan LEDs are located on the front and the rear of the router. Figure 2 shows the fan LEDs on the front of the router and Figure 3 shows the fans LEDs on the rear of the router.

(see Figure 2).

Figure 2: Fan Status LEDs on the front of the Router

Figure 3: Fan Status LEDs on the rear of the Router

1 — Fan tray	3 — Two-hole Protective grounding terminal
2 — Fan tray LEDs

Table 1 describes the behavior of the fan LED.

Table 1: Fan Status LEDs
Label	Color	State	Description
STATUS (Fan status)	Green	Blinking	Fan hardware initialization is complete. Software initialization is pending.
	Green	On steadily	Software initialization is complete, and the fan is functioning normally.
	Yellow	On steadily	Equipment is faulty and malfunctioning.
	Dark	Off	Fan tray input power failure.

Airflow

The router has a front-to-back (AIR OUT) cooling system . Air is pulled through the front of the chassis toward the fan trays, which exhaust the air out of the router.

Figure 4: Airflow Through the Chassis

Air Filter Unit

The air filter unit consists of four parts: the outer filter cover, the air filter, the inner cage, and the side brushes. The air filter sits right inside the outer filter cover and the inner cage. The air filter unit is installed in the front of the chassis and is secured to the rack rails by captive screws.

Figure 5: Air Filter Unit

1 — Outer filter cover	3 — Inner cage
2 — Air filter	4 — Side brushes

Note:

You must replace the air filter every 6 months.

Power Supply Cooling System

The power supply modules (PSMs) are self-cooling and are located in the front of the router.

Each PSM has its own fan and is cooled by its own internal cooling system. The PSMs in an ACX7332 router support back-to-front airflow (airflow in or AFI). This is because the PSMs on ACX7332 routers are installed on the front panel of the chassis and the ACX7332 chassis supports front-to-back airflow (airflow out or AFO).The AFI airflow of the PSMs supports the AFO airflow of the ACX7332 chassis.