It is used in power distribution systems and grounding electrical equipment in homes, commercial buildings, and industrial facilities. Each DISTRIBUTION BOX and controller must be grounded. 26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. 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. This helps to reduce the potential difference that exists between conductive parts and the earth. A correct understanding of the basic principles involved will help him/her to avoid mistakes in grounding system design. Protective grounding boxes are essential safety devices used in electrical systems to protect against electrical hazards by providing a low-impedance path to ground for fault currents. While it is a priority to protect the employees who maintain the transmission lines or.