The grounding wire is typically left bare and not insulated to maximize its effectiveness in dissipating excess electrical energy into the ground. Here’s why it’s often left bare:

1- Conductivity: A bare wire has direct contact with the ground, allowing for better conductivity. This direct contact ensures efficient dissipation of excess electrical current, especially in the event of a fault or surge, diverting it safely into the ground.
2- Resistance to Damage: Insulation on a wire might deteriorate over time due to environmental factors like moisture, heat, or physical wear. By keeping the grounding wire bare, there’s less risk of insulation breakdown, ensuring consistent and reliable conductivity.
3- Efficiency in Earth Contact: Insulation on the wire could create a barrier between the wire and the surrounding soil, hindering direct contact. The absence of insulation allows the wire to make direct contact with the earth, optimizing the grounding system’s effectiveness.
However, it’s crucial to note that in certain situations or specific environments where there might be a risk of accidental contact or where safety regulations require it, the grounding wire could be insulated for protection against unintended contact, especially in areas accessible to people or animals.