This article is about Accidental Ground Circuit or unintentional ground. Here we will define basics of ground fault which states that when straying electrical current (unintentional current) flows to the ground.
Accidental Ground Circuit | What is an unintentional ground?
This article can be explained by following factors.
- Resistance of the Human Body.
- Current Paths Through the Body.
- Accidental Circuit Equivalents.
- Effect of a Thin Surface Layer of Crushed Rock.
Resistance of the Human Body
The human body represents noninductive resistance at normal power frequencies of AC and DC. The resistance is between extremities, that is, from one hand to both feet, or from one foot to the other one. In either case, the value of this resistance is difficult to establish. The resistance of the internal body tissues, not including skin, is approximately 300ohm, whereas values of body resistance including skin, ranging from 500- 3000ohm.
Current Paths Through the Body
It should be remembered that the choice of a 1000 ohm resistance value relates to paths such as those between the hand and one or both feet, where a major part of the current passes through parts of the body containing vital organs, including the heart. It is generally agreed that current flowing from one foot to the other is far less dangerous. Referring to tests done in Germany, Loucks mentioned that much higher foot-to-foot than hand to foot currents had to be used to produce the same current in the heart region, stating that the ratio is as high as 25:1.
Step Voltage Circuit Diagram
Touch Voltage Circuit Diagram
Read Also: Permissible Body Current Limit as per IEEE Std 80
Please read following document reference to understand full about step voltage circuit, touch voltage circuit, human body resistance effect, How current make paths through body, Effect of a Thin Surface Layer of Crushed Rock.
With help of above document you can find following question answers and you can also give answers in comment section.
- What is a ground circuit fault?
- What happens when a circuit is shorted to ground?
- Can a ground fault cause a fire?
- Is a ground intentional or accidental?
- What is the most common cause of ground faults?
- How do you fix a ground fault?
- How do you find a ground fault in a circuit?
- How do we detect ground fault?
- Where does a ground fault go?
- What is the difference between a ground fault and a short circuit?
- Can a ground wire trip a breaker?
- What causes a ground fault circuit breaker to trip?
- What happens if a ground wire touches a live wire?