What should the ground resistance be kept below with a driven ground rod?

The ground resistance with a driven ground rod should be kept below 25 ohms. This is a common standard in electrical safety practices to ensure effective grounding. Maintaining ground resistance at or below this level helps to ensure that in the event of a fault, the electrical current has a safe and low-resistance path to the ground, which helps to protect both equipment and personnel from electrical shocks and ensures that protective devices, like circuit breakers and fuses, will operate properly. Keeping the ground resistance within this threshold improves the overall reliability of the grounding system and enhances safety measures. Higher resistance values can lead to less effective grounding, potentially posing safety risks in case of a fault condition.