Mx240 Craft Interface Overview - Juniper MX240 Hardware Manual

Each AC power supply provides power to all components in the router. When two power supplies are
present, they share power almost equally within a fully populated system. If one power supply fails or
is removed, the remaining power supply assumes the entire electrical load without interruption. One
power supply can provide the maximum configuration with full power for as long as the router is
operational.
In the low-line (110 V) AC power configuration, the MX240 router contains either two AC power supplies
(nonredundant), located horizontally at the rear of the chassis in slots PEM0 and PEM1 (left to right); or
four AC power supplies (redundant), located in slots PEM0 through PEM3 (left to right). The low-line
configuration requires two power supplies, and the third and fourth power supplies provide redundancy.
Each AC power supply provides power to all components in the router. When two power supplies are
present in a non-redundant system or when four power supplies are present in a redundant system,
they share power almost equally within a fully populated system. If one power supply in a redundant
configuration fails or is removed, the remaining power supplies assume the entire electrical load without
interruption. Two power supplies provide the maximum configuration with full power for as long as the
router is operational.
Cooling system—The cooling system has redundant components, which are controlled by the host
subsystem. If one of the fans fails, the host subsystem increases the speed of the remaining fans to
provide sufficient cooling for the router indefinitely.

MX240 Craft Interface Overview

The craft interface allows you to view status and troubleshooting information at a glance and to perform
many system control functions. It is hot-insertable and hot-removable. The craft interface is located on
the front of the router above the card cage and contains LEDs for the router components, the alarm relay
contacts, and alarm cutoff button. See
Figure 6: Front Panel of the Craft Interface
NOTE: At least one SCB must be installed in the router for the craft interface to obtain power.
Figure 6 on page 38.
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