What is Step Voltage?
The potential range at which a human or animal stands in case of a fault, i.e., the distance to the grounding electrode, is the most important factor. This is called step voltage. Step voltage is considered as the potential difference (voltage) across 1 m for humans and 2 m for animals. Using proper grounding electrodes, touch and step voltages can be reduced.
Typical step voltage
Assuming a soil resistivity of 150 Ω/m, a grounding electrode radius of 0.5 m, and 100 V at the electrode, the resistance at a point 4 meters away from the electrode is calculated as:
Step voltage calculation
During thunderstorms, reducing step voltage minimizes current passing through us.
How to Protect Against Step Voltage?
If we are in open areas during thunderstorms, our heels should be together. The wider the distance between our feet, the more current will pass through us due to the parallel resistance formed.
