Reducing Earth Resistance: Ineffective Methods

Earth resistance is a measure of how easily electrical current can flow from an earthing electrode into the surrounding soil. Lowering this resistance is crucial for electrical safety, ensuring fault currents can be effectively diverted.

Analyzing Earth Resistance Reduction Techniques

Several factors influence earth resistance. Methods to reduce it typically involve increasing the electrode's contact surface area with the soil, decreasing the soil's resistivity, or improving the electrode's depth.

• Use of large size earth plates: Increasing the surface area of the earth electrode (e.g., using larger plates) enhances contact with the soil. More contact area allows current to dissipate more easily, thus reducing earth resistance. This method is effective.
• Burying the earth plate deep: Placing the earth electrode deeper into the ground can access soil layers with lower resistivity, especially if surface layers are dry or less conductive. This often helps in reducing earth resistance. This method is effective.
• Use of mixture of powder, charcoal and salt: Applying conductive materials like charcoal and salt around the earth electrode significantly lowers the resistivity of the soil immediately surrounding it. This improves conductivity and reduces earth resistance. This method is effective.
• Use of small size earth plates: Conversely, using smaller earth plates reduces the surface area in contact with the soil. This leads to higher resistance to current flow, thereby increasing earth resistance, not reducing it. Therefore, this method cannot be used to reduce earth's resistance.

Conclusion on Earth Resistance

Based on the analysis, using small size earth plates is the method that does not reduce, and actually tends to increase, earth's resistance.