What is the recommended extension for a ground bus or grid outside the periphery of a fence in outdoor industrial substations?

The recommended extension for a ground bus or grid outside the periphery of a fence in outdoor industrial substations is 3 feet. This guideline is important for ensuring safety and effective grounding practices.

Extending the ground bus or grid by this distance helps to provide adequate grounding while minimizing the risk of potential fault currents affecting people or equipment outside the fenced area. By having a 3-foot extension, there is sufficient grounding to dissipate electrical energy safely into the earth, helping to prevent electrical hazards that might arise from equipment malfunctions or lightning strikes.

Choosing a distance that is too short, such as 1 or 2 feet, may not provide enough coverage for effective grounding; similarly, extending it to 5 feet may not be necessary or practical, as it could lead to increased installation costs without significantly improving safety. Therefore, 3 feet strikes a balance between effectiveness and practicality in grounding configurations at industrial substations.