The metal box of the distribution box, the electrical installation board, and the metal base and casing of the electrical appliances in the box must be grounded. The protective neutral wire should be reliably connected through the terminal board. Each DISTRIBUTION BOX and controller must be grounded. Grounding of the units: Attach a ground wire from one of. Today, we're diving deep into the world of distribution box grounding, breaking down the standards, and shining a light on those sneaky mistakes that even experienced electricians sometimes make. Preparation: First, you need to prepare some necessary tools, including grounding wire, grounding rod, voltmeter, insulating gloves and insulating tools. Equipment Protection: Grounding protects substation.