Chassis Grounding; Power, Connection, And Cable Specifications; Figure 28: Power And Grounding Cable Lug - Juniper Internet Router M160 Hardware Manual

Chassis Grounding

To meet safety and electromagnetic interference (EMI) requirements and to
ensure proper operation, the router must be adequately grounded before power
is connected. A pair of threaded inserts (PEM nuts) are provided on the right
rear of the chassis for connecting the router to earth ground.
CAUTION: Before router installation begins, a licensed electrician must attach a
cable lug to the grounding and power cables that you supply. A cable with an
incorrectly attached lug can damage the router (for example, by causing a short
circuit).
To ground the router, connect a grounding cable to earth ground and then
attach it to the chassis grounding points. The grounding points are spaced at
0.625-in. (15.86-mm) centers. The accessory box shipped with the router
includes the cable lug that attaches to the grounding cable (see Figure 28) and
the UNC 1/4–20 screws (American) used to secure the grounding cable to the
grounding points. (The cable lug shown in Figure 28 is also used for the DC power
cables.) The grounding cable must be able to handle up to 82 A.

Figure 28: Power and Grounding Cable Lug

End view
0.55
0.08
The grounding cable must be 8-AWG (8.4 m 2 ) wire, minimum, or
as permitted by the local code.

Power, Connection, and Cable Specifications

To supply power to the router, connect power cables to a separate, dedicated power
source for each power supply and attach the cables to the terminal studs on the
circuit breaker box. Most sites distribute power through a main conduit that leads
to frame-mounted power distribution panels, one of which might be located at the
top of the rack that houses the router. A pair of cables (one input and one return)
connects each set of terminal studs to the power distribution panel.
CAUTION: There is no standard color coding for DC power cables. The color coding
used by the external DC power source at your site determines the color coding
for the leads on the power cables that attach to the terminal studs on the circuit
2.25
0.28
2 holes
0.25 0.63 0.37
Crimp area
All measurements in inches
Power Guidelines, Requirements, and Specifications
Preparing for Router Installation
67