Power; Fans - Juniper ERX - RELEASE 11.1.X HARDWARE GUIDE 03-23-2010 Hardware Manual

Figure 12: Data Flow When a Spare Line Module Is Active
For information about installing modules for line module redundancy, see "Installing
Modules" on page 31. For information about configuring and managing SRP module
redundancy, see JUNOSe System Basics Configuration Guide, Chapter 6, Managing
Modules.

Power

All E Series routers provide a power architecture that distributes redundant –48 VDC
feeds through the router to each line module, SRP module, and fan module where
DC-to-DC converters provide local conversion to the required secondary voltages.
The ERX310 router is available with either DC or AC power inputs. The AC-powered
version can be configured with one or two hot-swappable power supplies for optional
redundancy. (See Figure 5 on page 8 and Figure 6 on page 8.) The power supplies
convert AC power to internal –48 V redundant DC feeds that are then distributed
through the router.

Fans

Forced air-cooling keeps the temperature of the E Series modules and components
within normal operating limits. In ERX14xx models, six cooling fans are located in
a tray at the top of the router (Figure 1 on page 5). In ERX7xx models, four cooling
fans are located in a tray on one side of the router (Figure 3 on page 6). In the
Chapter 1: ERX Overview
17
Redundancy Features