Electrical Accidents: Understanding the Risks and Safety

1. What is an Electrical Accident?

An electrical accident is a process in which a person receives electrical energy, either directly or indirectly. This can range from simple electromagnetic radiation to situations where the victim becomes electrically coupled to the network.

2. Definition of Electrical Contact

Electrical contact refers to the probability of a human body being subjected to a potential difference, resulting in an electric shock due to the passage of current through it.

3. Physiological Effects of Electrical Current Above 5A

When an electrical current exceeding 5A passes through the human body, the following physiological phenomena may occur:

• Less than one cardiac cycle: Ventricular fibrillation, early electrocution (depending on the cardiac cycle phase), unconsciousness, and visible marks on the skin.
• More than one cardiac cycle: Reversible cardiac arrest, burns, unconsciousness, and visible marks on the skin.

4. Influence of Voltage in Electrical Accidents

• For a given state of the human body with a specific resistance value, the intensity of the current that circulates is determined by the magnitude of the voltage.
• The primary factor affecting the human body is the intensity of the electric current passing through it when subjected to a potential difference.
• The Low Voltage Electrotechnical Regulation (REBT) suggests safety voltages of 24V DC and 50V AC.

5. Direct Electrical Contact

Direct electrical contact occurs when a person comes into contact with active parts (phase and neutral) of an installation, or portions thereof, that are normally energized at a low voltage.

6. Indirect Electrical Contact

Indirect electrical contact happens when a person comes into contact with parts that are accidentally energized at a low voltage but are normally not energized.

7. Individual Reactivity to Electrical Accidents

• Healthy individuals generally have a natural resistance to electrical effects, while those with weaker constitutions may be better conductors of electricity.
• Tolerance and effects vary for each person and are influenced by their physical and psychological characteristics.