Attach a ground wire from one of the threaded studs (A) at the bottom of the housing, to the mounting plate (B). Covers wiring, placement, standards, and expert tips for a compliant setup. The correct connection method of Distribution box grounding wire mainly includes the following steps: 1. Each DISTRIBUTION BOX and controller must be grounded. This helps to reduce the potential difference that exists between conductive parts and the earth. Equipment Protection: Grounding protects substation. Whether you are an electrical contractor or a construction brigade, knowing how to properly and safely install distribution boxes is the basis of ensuring the safe operation of the entire system. Whether you're a seasoned pro or just starting out, this comprehensive guide will give you practical.