In an agricultural building, where a separate equipment grounding conductor is not part of a listed cable assembly and is installed underground, it shall be?

In agricultural buildings, the installation of a separate equipment grounding conductor (EGC) that is not part of a listed cable assembly and is installed underground must be insulated. The reason for this requirement is primarily for safety and to prevent potential electrical hazards. An insulated grounding conductor helps to ensure that it does not unintentionally come into contact with the grounding system or other conductive materials that could lead to short circuits or electrical shocks.

Additionally, insulation on the grounding conductor provides protection from moisture and corrosive soil conditions that can occur underground. This insulation enhances the durability and longevity of the conductor while maintaining its effectiveness in conducting stray or fault currents back to the grounding system.

In contrast, uninsulated or bare conductors can lead to exposure risks and are not suitable for underground installations where environmental factors can compromise safety. While stranded wire might offer flexibility, the requirement for insulation in underground applications ensures compliance with safety standards. Hence, using an insulated grounding conductor is essential in agricultural settings.