Juniper Networks MX240 manual Power Guidelines, Requirements, and Specifications

Appendix D

Power Guidelines, Requirements, and Specifications

■Chassis Grounding Specifications on page 165

■DC Power Specifications and Requirements on page 166

■AC Power Specifications and Requirements on page 171

■Site Electrical Wiring Guidelines on page 176

Chassis Grounding Specifications

To meet safety and electromagnetic interference (EMI) requirements and to ensure proper operation, the router must be adequately grounded before power is connected. To ground AC-powered and DC-powered routers, you must connect a grounding cable to earth ground and then attach it to the chassis grounding points using the two screws provided.

Two threaded inserts (PEM nuts) are provided on the upper rear of the chassis for connecting the router to earth ground. The grounding points fit UNC 1/4–20 screws (American). The grounding points are spaced at 0.625-in. (15.86-mm) centers.Figure 30 on page 55, or Figure 31 on page 58).

NOTE: Additional grounding is provided to an AC-powered router when you plug its power supplies into grounded AC power receptacles.

Grounding Cable Lug Specification

The accessory box shipped with the router includes one cable lug that attaches to the grounding cable (see Figure 61 on page 166) and two UNC 1/4–20 screws used to secure the grounding cable to the grounding points.

Chassis Grounding Specifications ■ 165