26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. It looks like two lines, and in fact they are all together. The main functions of repeated grounding are as follows; (1) Reducing the ground voltage of the leakage device housing. Each DISTRIBUTION BOX and controller must be grounded. Grounding of the units: Attach a ground wire from one of. • Good system grounding provides the path for normal load and fault currents while maintaining load and controls temporary overvoltage. Good equipment grounding ensures personnel safety. Most North American distribution systems have a neutral that acts as a return conductor and as an equipment. When lightning strikes or a rogue voltage surge decides to crash the party, proper grounding steps in like a seasoned bouncer, redirecting danger away from sensitive electronics and human lives.