Cooling System - Juniper MX204 Hardware Manual

3d universal edge router

Hide thumbs Also See for MX204:

Table of Contents

CHAPTER 3

Cooling System

MX204 Cooling System Description

Fan Trays

MX204 Cooling System Description on page 11

MX204 Fan Status LED on page 13

The cooling system components work together to keep all router components within the

acceptable temperature range.

The cooling system consists of the following features and components:

Fan Trays on page 11

Airflow on page 12

Power Supply Cooling System on page 13

The chassis monitors the temperature of the router components. 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 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.

The router has three fan modules (or fan trays) that install in the rear of the router. Each

fan modules contain one counter-rotating fan. The fan modules are hot-insertable and

hot-removable field-replaceable units (FRUs) (see

Figure 6 on page

12).

Table of Contents