Electric Shock

 

19 August, 2023.

In this post, we will see the concept of electric shock.

Electricity is a very common element that we see around us. Whenever we deal with electric current, one thing that always worries us is getting shocked by it. It is not an easy task to work with electricity; many factors have to be considered before working with it. We normal people usually just plug on the power supply socket and use devices for it. But, it is the main task of engineers who design it and ensure that power supply is given properly to the user at any moment. If a person accidentally touches a live electric wire, then there are many potential threats that can hamper his life. So, it is necessary to have a proper understanding of the electric shock which occurs. Electrical engineers working in any field, need to take special care on how to deal with electricity. In this post, we will see the concept of electric shock.

·        What is electric shock?

The term shock denotes something which comes suddenly and disturbs us. In the same way, an electric shock is a term which happens due to sudden electric current flowing through the human body and then disturbs us. Simply, consider that a person has accidentally touched a live wire. Live wire means electric current is flowing through it. Now, if that connection is not grounded properly (leakage in ground or no ground connection) or if that particular person has not worn any insulated material on his foot, then that electric current of the wire will immediately flow through the human body. A small level of current in mA (below 30) is manageable, but anything above it can disturb the person. A large amount of current can even cause death of the person. So, an electric shock is a very critical thing which must be handled with care.

Usually, AC voltages above 42V or DC voltages above 60V causes an electric shock or it means a person will start to experience it. Our human body is not able to handle such an amount of electricity flowing through our body and due to this, our internal parts get damaged quickly. There are two main reasons for causing an electric shock - contact with components that are supplied with a voltage in undisturbed operation (direct contact) and contact with components that are supplied with a voltage caused by a fault (indirect contact).

·        Electrical injuries:

1.      The very first thing which happens due to electric shock is burns. As electric current has a large amount of heat in it, our body parts first get internal burns. This is the main reason why our body cannot sustain electric current. A burn can be caused by temperatures that are the result of overloads, component failures, insulation damage or loose connections or those with high transition resistance.

2.      Apart from burns, other major issues that can occur are unconsciousness, muscular spasms, headache, irregular heartbeat, numbness or breathing problems. Also, if the injury was heavy, then there are chances of broken bones in your body.

3.      A person who receives electric shock can get phobia of electricity and he will become afraid lifetime to even go near a power supply or touch a wire. This can have long lasting effects on your brain thus.

·        Electric shock prevention:

1.      The basic step to avoid electric shocks is to provide proper grounding and insulated connections to the electrical equipment and power supply connections. This reduces electric shock by nearly half an amount.

2.      The electrical circuits must be properly separated from each other. This prevents short circuit or leakage chances. Also, the electrical equipment must have proper housing or cover, to prevent human from touching any live part. The active components inside the equipment must be insulated.

3.      Double/reinforced insulation must be given priority to electrical equipment protection class selection. This is the most advanced form of protection class for any electrical equipment. Also, fault current protection circuits must be given importance and tried to design in all the basic circuits.

4.      As soon as the person comes in contact accidentally, try to separate him by using a dry or non-conductive material (wood, plastic, newspaper or rubber). Or else, direct shut off the mains power supply.

5.      Apart from all of these, timely medical attention is a must. Also, preventive sign boards must be present near electrical equipment or wires, warning people of potential danger in touching it.

6.      Follow and read the given electrical standards for safety – IEC 61140 (protection against electric shock), IEC 60364-4-41 (electrical installations of buildings), IEC 62103 and EN 50178 (electronic equipment for use in power installations) and IEC 60204 (safety of machines and electrical equipment).

 

I have covered the general concept of an electric shock. I have also not attempted to cover every theory of these concept deeply; you can learn it easily once you get familiar with them. I have just given you an insight of these types of accidents and malfunctions. A great system understanding is required by the engineer who is designing the electrical circuit. Learn the basics and explore a new type of study in this type of engineering.

Thank you guys; I hope you enjoyed reading the practices normally used for this type of study in industrial automation.