Attach a ground wire from one of the threaded studs (A) at the bottom of the housing, to the mounting plate (B). The ground resistance between all system parts shall be < 0. Depending upon the. The correct connection method of Distribution box grounding wire mainly includes the following steps: 1. Preparation: First, you need to prepare some necessary tools, including grounding wire, grounding rod, voltmeter, insulating gloves and insulating tools. Covers wiring, placement, standards, and expert tips for a compliant setup.