03-03 Earthing in an AC system
Earth is part of the AC circuit
The ground is part of the AC circuit.
The human body is a #parallel path for electric current.
Current takes the "Path of Least Resistance."
Current flow through human body
Estimated effect of AC current:
| Current | Effect |
|---|---|
| 1mA | Barely perceptible |
| 10mA | Pain |
| 16mA | Max current and average man can grasp and "let go" |
| 20mA | Paralysis of respiratory muscles |
| 100mA | Ventricular fibrillation |
| 20,000mA | Typical circuit breaker trip rating, 20A |
| Most of the electrical resistance of the human body comes from dry skin. | |
| Wet skin has about 1000x less electrical resistance. |
Use an RCD to protect against electric shock.
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