Juniper EX4650 Series, Руководство по оборудованию, Страница: 23 / 195

The power supplies either have labels on the handles that indicate the airflow direction or they have
color-coded handles with a fan icon.An AFI label or a blue-colored handle indicates back-to-front airflow
while anAFO label or a gold-colored handle indicates front-to-back airflow. See Figure 7 on page 24
Figure 7: Power Supply Handle Detail
1
—
AFI label
CAUTION: Do not mix:
•
AC and DC power supplies in the same chassis.
•
Power supplies with different airflow labels (AFI and AFO) in the same chassis.
•
Power supplies and fan modules with different airflow labels (AFI) and (AFO)) in the
same chassis.
•
Verify that the airflow direction on the power supply handle matches the direction of
airflow in the chassis. Ensure that each power supply you install in the chassis has the
same airflow direction. If you install power supplies with two different airflow directions,
Junos OS raises an alarm.
•
If you need to convert the airflow pattern on a chassis, you must replace all the fans
and power supplies at one time to use the new direction.
Cooling System
EX4650 switches are shipped with five fan modules (4+1 redundancy) located at the rear of the chassis.
These fan modules are designed for one of the two available airflow directions. The fan modules are also
color-coded to indicate the airflow direction.
Figure 8 on page 25 shows the EX4650 fan module.
24