Power from factory ground must be installed by a qualified electrician. Each DISTRIBUTION BOX and controller must be grounded. Grounding of the units: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. This helps to reduce the potential difference that exists between.