Single-point grounding is the preferred method because it generally yields the lowest potential difference in the work zone and because it usually requires less grounding equipment and effort to install. The protective grounding system, which includes conductor grounds and worker bonding, must be engineered to protect workers from hazardous voltages that can be created by line reenergizing, lightning, or induced oltage. If more than one crew is working independently on the same deenergized line or. 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. The equipment grounding conductor (s).