The requirements for equipment grounding electrodes are found in NESC Rule 94. These are installed for each distribution transformer or lightning arrester instal-lation. The NESC requires a minimum electrode nominal diameter of 1/2" or 5/8", depending upon material, and a. 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. If you're working with electrical systems, you know that grounding isn't just some bureaucratic requirement—it's literally the difference between a safe, functional system and a potential disaster. The topic of system grounding is extremely important, as it affects the susceptibility of the system to voltage transients, determines the types of loads the system can. 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. Grounding of the units: Attach a ground wire from one of. IPMENT, STRUCTURES, ETC. IN ELECTRICAL STATIONS INCLUDING TRANSMISSION AND DISTRIBUTION SUBSTAT GR THAN 8 FT FROM THE FENCE. THE FENCE SHALL BE GROUNDED SEPARATELY FROM THE GRID UNLESS OTHERWISE NOTED ON THE A PROPRIATE PROJECT DRAWING. 7 Provide conduit grounding bushings, bonded together and connected to the equipment enclosure on all incoming and outgoing conduits on distribution switchgear and switchboards, distribution panels and on all conduits over 1-1/4” diameter at all panelboards, pull boxes and equipment.