5 is an article in the National Electrical Code that addresses requirements for underground electrical installations, including minimum cover requirements—the measurement used to determine the distance from the top of an underground cable or raceway to the finished grade. Paragraph (d) of this section also applies to protective grounding of other equipment as required elsewhere in this Subpart. 5 (A) for underground installations. Whether you're a seasoned pro or just starting out, this comprehensive guide will give you practical. 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. It can also be an aid to all engineers responsible for the. However, if the conductors are protected by an overcurrent device rated at not more than 20 amperes and provided with ground-fault circuit-interrupter (GFCI) protection for personnel, the burial depth may be reduced to 12 in.