If the resistance of a ground rod exceeds 25 ohms, what should be done?

When the resistance of a ground rod exceeds 25 ohms, adding another rod or driving one beside the existing one is an effective method to improve grounding. Grounding systems are designed to disperse electrical faults safely into the ground, and a resistance above 25 ohms indicates that the existing ground rod may not provide adequate fault current dissipation.

By introducing an additional ground rod, you create a parallel path allowing for improved conductivity and a lower total resistance. This increased surface area for grounding in combination with potential soil moisture variations provides a more effective grounding solution.

Other approaches like replacing the rod with a larger one or adjusting connection wires may not guarantee a reduction in resistance to below the acceptable threshold. Checking grounding connections is important for the integrity of the system but does not address the fundamental issue of high resistance in the ground rod itself. Thus, adding another rod is the most practical and direct solution to ensure effective grounding.