Juniper EX3300 Series User Manual

Cooling System and Airflow in an EX3300 Switch
The cooling system in an EX3300 switch consists of two fans: one along the rear of the
chassis and another along the left side of the chassis. The fans provide front-to-back or
back-to-front chassis cooling depending on the switch model. Table 11 on page 22 shows
the different EX3300 switch models and their direction of airflow.
Table 11: Airflow Direction in EX3300 Switch Models
Direction of AirflowModel
Front-to-backEX3300-24T
Front-to-backEX3300-24P
Front-to-backEX3300-24T-DC
Front-to-backEX3300-48T
Back-to-frontEX3300-48T-BF
Front-to-backEX3300-48P
In front-to-back airflow models, the air intake is located on the front of the chassis. Cool
air is pulled into the chassis and pushed toward the rear of the chassis. Hot air exhausts
from the rear of the chassis. See Figure 10 on page 22.
Figure 10: Front-to-Back Airflow Through the EX3300 Switch Chassis
g021205
Chassis rear
Chassis front
Fan
Fan
Air intake
Fan air
exhaust
Air intake
Air exhaust
Copyright © 2011, Juniper Networks, Inc.22
Complete Hardware Guide for EX3300 Ethernet Switches

Juniper EX3300 Series Specifications

General

Layer Support	Layer 2 and Layer 3
JUNOS OS	Yes
Ports	24 or 48 x 10/100/1000BASE-T ports
Uplink Ports	4 x 1GbE/10GbE SFP/SFP+ ports
Power Supply	AC or DC options
Stacking	Yes, up to 10 units
MAC Address Table Size	32, 000
Operating Humidity	10% to 90% non-condensing
PoE Support	Available on PoE models
Virtual Chassis	Yes, up to 10 units
Operating Temperature	32° to 104° F (0° to 40° C)