After any major change to an electrical distribution system, every three years (maximum), or if ground-related issues are suspected, a qualified electrical contractor or professional engineer should verify the grounding system is in accordance with the National Electric Code. After any major change to an electrical distribution system, every three years (maximum), or if ground-related issues are suspected, a qualified electrical contractor or professional engineer should verify the grounding system is in accordance with the National Electric Code. This section applies to grounding of transmission and distribution lines and equipment for the purpose of protecting employees. Paragraph (d) of this section also applies to protective grounding of other equipment as required elsewhere in this Subpart. 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 International Electrotechnical Commission (IEC) has developed standards that guide engineers, installers, and safety officers in designing safe and. Abstract: Discussed in this recommended practice is the system grounding of industrial and commercial power systems. The recommended practices in this document are intended to provide explanations of how electrical systems operate.
