In rocky ground, what is an approved method for installing a temporary ground rod?

• A. Drive a 10' rod vertically
• B. Drive an 8' rod at an angle until flush with the ground
• C. Use a copper grounding plate
• D. Place the rod horizontally

Answer: (B)

In rocky ground conditions, driving an 8' rod at an angle until it is flush with the ground is an approved method for installing a temporary ground rod. This approach allows the grounding rod to effectively make contact with the soil while accommodating the challenging terrain, as driving a rod vertically may not be feasible due to the resistance from the rock.

When the rod is angled, it can bypass some of the rock layers and reach deeper, potentially less resistant soil, thus improving the electrical conductivity for grounding purposes. This method also ensures that the installation meets safety codes while providing the necessary grounding for temporary electrical systems.

Other methods, such as placing the rod horizontally or using a copper grounding plate, may not be as effective in ensuring proper grounding in rocky conditions, and driving a 10' rod vertically could be impractical. Therefore, angling the rod facilitates a balance between achieving adequate grounding and addressing the physical constraints posed by the rocky terrain.