When rock is encountered, ground rods must be driven at an angle not to exceed what degree from vertical?

When installing ground rods in rock, it is essential to drive them at a specific angle to ensure proper grounding and stability. A maximum angle of 45 degrees from vertical is recommended because this angle allows for effective grounding while also accommodating the challenges posed by rocky soil conditions. Driving the rod at too steep of an angle might not achieve the desired electrical connection and could compromise the grounding system's effectiveness. At 45 degrees, the rod can make better contact with the surrounding earth, improving its conductivity and ensuring adherence to safety standards.

If the rod were driven at angles steeper than 45 degrees, such as 30 degrees or less, it could compromise its depth of insertion and contact with the earth, which is crucial in grounding applications. Similarly, angles exceeding 45 degrees—like 60, 75 degrees—could also hinder the grounding capability. Thus, maintaining a 45-degree limit ensures optimal function and safety for the grounding system in the presence of rock.