Juniper M120 - Chassis Components and Descriptions; M120 Router Chassis Description

CHAPTER 3
Chassis Components and Descriptions
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M120 Router Chassis Description on page 7
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M120 Midplane Description on page 9
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M120 Cable Management System Description on page 10
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M120 Craft Interface Description on page 11
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M120 Alarm LEDs and Alarm Cutoff/Lamp Test Button on page 13
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M120 Component LEDs on the Craft Interface on page 14
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M120 External Clock Interface Ports on the Craft Interface on page 16
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M120 Alarm Relay Contacts on the Craft Interface on page 17
M120 Router Chassis Description
The router chassis is a rigid sheet metal structure that houses all the other router
components (see Figure 1 on page 8, Figure 2 on page 8, and Figure 3 on page 9). The
chassis measures 20.75 in. (52.71 cm) high, 17.43 in. (44.3 cm) wide, and 24.3 in. (61.7 cm)
deep (from the front-mounting flanges to the rear of the chassis). The chassis installs
in standard 800-mm (or larger) enclosed cabinets, 19-in. equipment racks, or telco
open-frame racks. Up to four routers can be installed in one standard (48-U) rack if the
rack can handle their combined weight, which can be greater than 900 lb (408.4 kg).
The chassis includes three electrostatic discharge points (banana plug receptacle). Two
are located in the front of the chassis and one in the rear of the chassis.
CAUTION: Before removing or installing components of a router, attach an
ESD strap to an ESD point and place the other end of the strap around your
bare wrist. Failure to use an ESD strap can result in damage to the router.
WARNING: The router must be connected to earth ground during normal
operation.
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