26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. Grounding is a mechanism to protect distribution equipment and people under normal operating conditions, abnormal operational (overcurrent and overvoltage) responses, and hazardous conditions such as shocks. Equipment Protection: Grounding protects substation. Power from factory ground must be installed by a qualified electrician. Each DISTRIBUTION BOX and controller must be grounded. The voltage, system arrangement, loads connected, and continuity of. Any engineer dealing with power supply networks needs to understand the basic principles of grounding system design and its role in ensuring safety of equipment and personnel.