Attach a ground wire from one of the threaded studs (A) at the bottom of the housing, to the mounting plate (B). This helps to reduce the potential difference that exists between conductive parts and the earth. Equipment Protection: Grounding protects substation. 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. Grounding is necessary to assure correct operation of electrical devices, to assure safety. Power from factory ground must be installed by a qualified electrician. 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.