26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. Power from factory ground must be installed by a qualified electrician. Grounding of the units: Attach a ground wire from one of. Whether you're a seasoned pro or just starting out, this comprehensive guide will give you practical insights into proper grounding techniques, with a special focus on how selecting quality materials from a reliable building material supplier impacts your entire system's safety and longevity. Part (1) of Section 370-16 (a) describes in detail the method of counting wires, as well as clamps, fittings, or devices (i., switches, receptacles, combination devices) - by establishing an equivalent conductor-value for each. These values are added together to get a total number of conductors. Ensure safe placement: install in dry, accessible areas with good ventilation and at appropriate height (typically ~1. Practice good wiring: secure. 1) Generally, the incoming line of power distribution box adopts five wire system, that is, a, B and C three-way phase line (the general color is yellow, green and red), one way zero line (the color is light blue) and one way ground line (the color is yellow with green stripes).