Grounding study has been around ever since the electrical power system started. However, it began with experimental or theoretical analysis on which different authors based their rough expressions. They were carried on a vertical grounding or single horizontal rod. Read further to understand the purpose of grounding grid analysis and why it is necessary.
Grounding Study—Why is it Crucial?
The grounding study aims to limit the accidents related to electric shock. The situations that can otherwise lead to the shock accidents include:
- High fault current reaching the ground
- Large soil resistivity
- Connecting two points of large potential difference
- Lack of adequate contact resistance
This is where grounding studies come to the rescue. They can be designed to keep touch voltages and steps within safe limits. Moreover, through a ground study, you can design time savings as well as material cost savings. This can be done by determining the conductor’s minimum size, and the number of ground rods needed o keep the potential value under the IEEE limit.
Steps Taken During Grounding Study
Here are the following steps that are taken during the grounding study:
- Soil Resistivity
Grounding system resistance is essential to ensure that the current devices are operating at satisfactory levels. This is because the rise of a grounding system in a ground fault condition is directly proportional to the grounding system’s resistance. Therefore, it is vital to predicting the grounding systems’ resistance. - Voltage Gradient Effect
The ground resistance is affected by the voltage gradient if it is higher than 103 Volts/cm. In such a situation, the arcs begin at the electrode surface and then progress into the ground. This increases the electrode size that the soil is able to withstand. - Determine Maximum Ground Fault Current
For this location and the type of ground, faults are expected to generate the greatest current flow between the surrounding earth and the grounding grid, producing the rise in grid potential concerning remote earth.
Nonetheless, the typical applications of this study are at:
- Substations
- Switchyards
- Generation sites
- Communication sites
- Industrial facilities
For more information about grounding study analysis or assistance, contact us today. Let our experts help.
