Juniper Networks M160 manual Chassis Grounding, Power, Connection, and Cable Specifications

Preparing for Router Installation

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	2.25
0.55	0.28
	2 holes
	Crimp area

0.08 0.25 0.63 0.37 All measurements in inches

g002137

The grounding cable must be 8-AWG (8.4 m2) 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

Power Guidelines, Requirements, and Specifications 67