26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. On the US market, a 5. Each DISTRIBUTION BOX and controller must be grounded. 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. The National Electrical Code (NEC) provides clear guidelines for ground wire sizing through Table 250. 122, but understanding how to apply these requirements correctly can make the difference between a safe installation and a costly code violation. The EGC is the wire found in branch circuits, typically green or bare, and the GEC is the dedicated wire connecting the main service panel to the physical ground outside. How to make proper & safe electrical ground wiring connections in the box: This article describes options for connecting a metal electrical box to the grounding conductor & connecting the grounding conductor to a fixture such as a ceiling light or ceiling fan. As technology advances, including the rise of smart home devices and renewable energy.