MX480 Chassis Grounding Specifications

MX480 Chassis Grounding Points 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 (see Figure 1 or Figure 2).

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

Figure 1: Connecting AC Power to the Router

Figure 2: Connecting DC Power to the Router

MX480 Router Grounding Cable Lug Specifications

The accessory box shipped with the router includes one cable lug that attaches to the grounding cable (see Figure 3) and two UNC 1/4–20 screws used to secure the grounding cable to the grounding points.

Figure 3: Grounding Cable Lug

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.

Note: The same cable lug is used for the DC power cables.

MX480 Router Grounding Cable Specifications

The grounding cable that you provide must meet the specifications in Table 1.

Warning: The router is pluggable type A equipment installed in a restricted-access location. It has a separate protective earthing terminal (sized for UNC 1/4-20 ground lugs) provided on the chassis in addition to the grounding pin of the power supply cord. This separate protective earthing terminal must be permanently connected to earth.