M40e 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. 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.

To ground AC-powered and DC-powered routers, 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 1) and the UNC 1/4–20 screws (American) used to secure the grounding cable to the grounding points. (The cable lug shown in Figure 1 is also used for the DC power cables.) The grounding cable must be able to handle up to 68 A.

Figure 1: M40e DC Power and Grounding Cable Lug

The grounding cable must be 6-AWG (13.3 mm²) wire, minimum, or as permitted by the local code.

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