26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. Power from factory ground must be installed by a qualified electrician. Grounding of the units: Attach a ground wire from one of. The correct connection method of Distribution box grounding wire mainly includes the following steps: 1. The longevity and dependability of essential electrical components are both preserved with the assistance of this protection. Preparation: First, you need to prepare some necessary tools, including grounding wire, grounding rod, voltmeter, insulating gloves and insulating tools. Make sure all tools are intact to prevent accidents during the grounding. Whether you're a seasoned pro or just starting out, this comprehensive guide will give you practical insights into proper grounding techniques, with a special focus on how selecting quality materials from a reliable building material supplier impacts your entire system's safety and longevity.