Router User Manual

ERX 8.0.x Hardware Guide
Fans
Forced air-cooling keeps the temperature of the E-series modules and components
within normal
operating limits. In ERX-14xx models, six coolin g fans are located
in a tray at the top of the router (Figure 1). In ERX-7xx mod els, four cooling fans
arelocatedinatrayononesideoftherouter(Figure3). IntheERX-310router,
two cooling f
ans are located in a tray on one side of the router (Figure 5).
The system mo
nitors the temperature of each mod ule. I f the temperature of a
module exceeds the maximum limit, the system imm ediately goes into thermal
protection mode and the m od ules are powered off. The ERX system controller
enters a low p
ower mode, keeps the modules in a power-off condition, and does
not respond to any management interface commands. For information about
troubleshooting high operating temperatures, see “Troubleshooting” on page 103.
In ERX-7xx and ERX–14xx models, the fan tray has two redundant converters
that power t
he fans (for the ERX-14xx models, a –24 V, 50 W converter; for the
ERX-7xx m od el s, a –1 2 V, 15 W converter). If one converter fails, the other
takes over. The ERX-310 router does not have redundant converters.
For all E-series routers, the system software reports an alarm if any
of the fans
or converters fail.
20 Redundancy Features