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. Need help?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. Proper grounding conductor sizing is critical for. 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. It ensures safe fault current paths, compliance with NEC codes, and reliable protection for residential, commercial, and industrial installations. Grounding and Bonding and the NEC 250 Training. Here are the steps on how to ground a power distribution box: 1.
[PDF Version]