Current Or Voltage That Kills? - Ppt Download

Dear All,

When I search on the internet, I found the following sentence on almost every site: "It's not voltage that kills, it's current!" Without the existence of voltage, current will not produce. So, how can we justify the above? Both are required to kill a person – current as well as voltage.

During my discussion with someone today, I mentioned the sentence: "It's not voltage that kills, it's current!" However, I was unable to justify my answer in the end.

Can 24V kill a person? Normally, we consider a 24V supply as a safe voltage, but can this 24 voltage still kill a person?

Can anyone provide a solution to my query? I hope to receive some solutions to the above two queries.

Thanks in advance.

Dear Mr. Dipil,

Still, I am unable to understand the current, voltage, and ampere. Even though the power supply is 24 volts, if the amperage is higher, it can be lethal. (This was mentioned by an electrical engineer, but I am struggling to grasp it). There are many things in this world that we are unable to comprehend, and this is one of them.

Let us look forward to hearing from our knowledgeable members.

Dear Dipil,

Kindly visit the following links. I hope you can get a satisfactory answer.

- [What kills people: current or voltage](http://wiki.answers.com/Q/What_kills_people_current_or_voltage)
- [Which kills humans: voltage or current](http://wiki.answers.com/Q/Which_is_kill_the_human_voltage_or_current)

Regards,
Sandy

Dilip,

Current never kills a person; it's voltage. Think of a situation where you are hanging in the air with the help of a current wire. The current will move through your body, but it will not kill you because there is no voltage difference between your body parts. You can see birds sitting on a current wire, but they do not die. The same goes if your body is touching the earth or any other electricity conducting materials; it will create a voltage difference between your body parts and can lead to death. So, it's clear that voltage differences kill a person, not current.

If the voltage difference is just 24 V, it can't kill a person but can cause harm.

I hope this clears your query! If not, please respond here.

There are various criteria concerning the causes of fatal effects of electricity, which are relevant to current, voltage, amperes, and the body resistance level of a human being. For the correct answer to your question, you may please try to check the following link that explains in brief different aspects about the fatal effects of electric current: [Electric Current Needed to Kill a Human](http://hypertextbook.com/facts/2000/JackHsu.shtml)

Dear All,

The quantity of current is the one that determines the type of damage caused to the human body. However, the quantity of current is decided by the voltage and resistance of the victim at the time of contact.

The severity of shock is determined by the quantity of current flow:
- 1 milliamp: Skin tingling
- 9 milliamps: Starts freezing of muscles
- 30 milliamps: Breathing difficulty
- 75 milliamps: Breathing stops
- 100 to 200 milliamps: Ventricular Fibrillation of the Heart

BS Gopala Krishna
bskrishnagopala@gmail.com
9731398860
EHS Consultant, Bangalore

Dear Mr. Dipil,

Attached is a PowerPoint presentation which is self-explanatory. I was invited to the Government College of Polytechnic where I delivered this presentation for the professors as part of a "Train the Trainer" session. This was conducted under the Industry/Government Institutes Partnership program.

Thanks, Sudhir

Dear Pon,

I do not think that this is a childish question. If you analyze the replies given by our members, you can find the controversy. If you feel this is a childish question, please come up with an answer supported by technical explanations.

Quoting the following sentence from another website, can you go through it and share your views?

Provided a much lower body resistance figure augmented by contact with a ring (a band of gold wrapped around the circumference of one's finger makes an excellent contact point for electrical shock) or full contact with a large metal object such as a pipe or metal handle of a tool, the body resistance figure could drop as low as 1,000 ohms (1 kΩ), allowing an even lower voltage to present a potential hazard:

E = IR

E = (20 mA)(1 kΩ)

E = 20 volts

Notice that in this condition, 20 volts is enough to produce a current of 20 milliamps through a person, enough to induce tetanus. Remember, it has been suggested that a current of only 17 milliamps may induce ventricular (heart) fibrillation. With a hand-to-hand resistance of 1000 Ω, it would only take 17 volts to create this dangerous condition.

Be specific and try to give a positive response instead of just throwing negative comments. We are here to discuss issues and bring out the best possible solutions that will be beneficial to all. If you still feel it is a childish question, please ignore it and don't waste your precious time replying.

Thank you.

Dear All
Sorry for not responding to any of the reply’s... I will review and replying to all the replies after tomorrow... I am appearing to my exams and little bit busy in my studies... Thanks a lot to all for participation and giving excellent views...
I am very happy to see many reply’s to this thread...
Keep on sharing your expertise...

Dear All,

But Mr. Gopala Krishna, in our markets, the ELCBs are available, which only break the circuits when the leakage is more than 30 milliamps. Will it not cause any damage to the life or body parts of the victim?

The quantity of current is the determining factor in the type of damage caused to the human body. The quantity of current is influenced by the voltage and resistance of the victim at the time of contact.

The severity of a shock is determined by the quantity of current flow:
- 1 milliamp - Skin tingling
- 9 milliamps - Starts freezing of muscles
- 30 milliamps - Breathing difficulty
- 75 milliamps - Breathing stops
- 100 to 200 milliamps - Ventricular Fibrillation of Heart

Best regards,
BS Gopala Krishna
EHS Consultant, Bangalore
Email: bskrishnagopala@gmail.com
Phone: 9731398860

Dear Mr. Sandy,

Thank you for your inputs into the thread and for providing links to the website. I fully agree with the content in the first link you provided, i.e., "Current that kills, not the voltage."

However, the statement in the second link is what confuses me. Can you provide more clarification on the sentence below from the website: "Can this 15mA kill a person, if so, under what conditions? The current through the heart is what kills you. It only takes a few milliamps to disrupt the heartbeat (about 15mA for men and 10mA for women, though this varies from person to person).

Dear Mr. Koshi,

Thank you for your reply to the thread, and I apologize for the delay in responding. I have been actively reading on the topic and engaging in discussions with various individuals, including this forum.

I have posed the questions you raised to experts in the field of Electrical and received the following responses. I kindly request you to review them and share your perspectives:

1. While voltage (potential difference) is necessary for the flow of current, it is the current that is lethal. For instance, if individuals with varying body conditions touch the same voltage, the one with a wet body will experience a stronger shock due to the relationship between current, voltage, and resistance. High current can damage nerves and lead to fatality.

To simplify, consider a tank full of water connected to a pipe. The stored water represents potential voltage, and when the knob is turned on, the water flow symbolizes current. The danger lies in the current, not the voltage.

2. When a bird or a person is on a wire, the potential difference between limbs is minimal or zero, resulting in low current. However, if a person's leg touches the ground or a post, the potential difference increases significantly, leading to dangerous levels of current.

3. In the case of 24V, the risk of Ventricular Fibrillation is minimal, although a jolt is possible. Regarding this voltage level, it seems you share the same perspective.

I eagerly await your feedback to reach a conclusive decision on this matter.

Dear Sir,

Thank you for your participation in the thread. You have provided an informative link that shows the results of various authors' studies. This data appears to be authentic, and according to this website, 24 V cannot kill a person or induce ventricular fibrillation.

"The damage caused by electric shock depends on the current flowing through the body - 1 mA can be felt; 5 mA is painful. Above 15 mA, a person loses muscle control, and 70 mA can be fatal."

During our earlier discussions on this site, we came to the conclusion that "it is estimated that 50 mA is sufficient to cause ventricular fibrillation."

I look forward to hearing more from you and encourage you to continue participating and sharing your expertise with us.

Dear Mr. BS Gopala Krishna,

Thank you for your input into the thread.

I do agree with your statement "QUANTITY OF CURRENT FLOW DETERMINES THE SEVERITY of shock."

According to this link: Which is kill the human voltage or current,

Actually, voltage is the electric potential, or potential energy for each electron, not potential energy. Current is the rate at which the electrons flow. To see the effect it would have on a person, consider this: if you have high current and low voltage, then the electrons would not have much energy, but there would be a lot of them flowing into your body because the current is high. However, if the voltage is high and the current is low, then the electrons would carry more energy, but there would not be many of them flowing into your body because the current is low. Looking at it this way, current and voltage should be equally deadly, but in real life, current is more life-threatening. This is because your heart uses electrical impulses to control how fast your heart beats and if you get a few high voltage electrons, it won't really affect your heart rate, but getting a lot of them at low voltages would.

I hope to receive your comments to reach a common conclusion on this topic.

Dear Sir,

Thank you for providing a nice presentation on Electrical Safety. Can you please give clarifications on the following two points in the presentation:

1. AC reverse polarity is not hazardous. How?
2. It takes high voltage to kill; 120 volts is not dangerous. Why?

Considering the formula I = V/R, and if R = 1000 Ohm = 1 Kilo Ohm, let's consider a wet condition with the least resistance:

I = 120/1 = 120 mA

This 120 mA is enough to cause Ventricular Fibrillation leading to death. In America, I believe 120 V supply exists, and there have been cases of electrocution reported from there. Hence, I think any voltage exceeding 30 Volts is dangerous to human beings as it can produce a current of 30mA, which is perilous to human life.

I would appreciate your comments on the points mentioned above.

Dear Mr. Bhaskar,

Thank you for your participation in the thread and for raising concerns to make the discussions more interesting. I also appreciate your interest in learning more.

I would like to share my comments on the raised concern with you:

1. An ELCB with a 30mA rating will always trip below 30mA current, preventing the flow of current exceeding 30mA.

2. Another factor to consider is the time taken for tripping, which ranges between 0.1 - 0.2 seconds and can be adjusted. During this short duration, if a current below 30mA passes through a human body, only a tingling sensation may occur.

3. If a current of 20-30mA flows through the human body, muscle contraction can cause respiratory paralysis. While this is dangerous, it is retrievable and does not lead to death. This information is based on what I have read and learned from various discussions.

I look forward to hearing your views.

Dear All,

Looking to have a great conclusion to the discussion by bringing clarity to the below point:

1. Whether 24 V can kill a person or not?

In some of the websites and in one book which I read, it is written that "Any current over 8mA is considered potentially dangerous depending on the path the current takes, the amount exposed to the shock, and the physical condition of the person receiving the shock." If the resistance is 1000 Ohms or below, even a current of 24 V can create more than 8mA.

Looking forward to the participation of senior members. Thanks in advance.

Dear Dipil,

First of all, I am very sorry for the late reply. I was quite confused about this topic and not sure about my answer, which is why I did not put any comments on this thread.

Yesterday, I had a discussion with one of my friends. He is an electrical engineer, and he explained it simply and provided me with the attached document and link. Now, I am 100% sure about my answer, Dipil.

You are right, current kills the person, not voltage.

Mr. Sandy, Mr. Joshi, Mr. Ps Dhingara, Mr. Gopal Krishna, Mr. Sudhir, and Mr. Bhaskar, thank you for your inputs on this thread.

Dear Dipil,

Here is the link for the difference between current and voltage: [Difference Between Current and Voltage | Difference Between | Current vs Voltage](http://www.differencebetween.net/technology/difference-between-current-and-voltage/)

I don't have time to go through your previous posts right now, but I will get back to you as soon as possible.

Keep in touch.

Dear all,

The 30 mA current causes breathing difficulty and does not cause fatality. Time taken to trip is also a few milliseconds. Hence, a 30 mA sensitivity ELCB will save lives in case of electric shock.

BS Gopala Krishna
BE, Electrical, DIP In Ind Safety (CLI)
9731398860
EHS consultant, Bangalore

Dear friends,

Electricity in the human body is like toxic chemicals entering the body. We call it a dose, the minimum amount to cause damage.

Consider sleeping pills and their dosage.

You take one sleeping pill a day. It helps you fall asleep, and you experience some effect.

Similarly, with a small amount of current - 10mA, 20mA, or 30mA - there is a sensation of shock, varying in intensity based on factors like physique, gender, humidity, and others.

If you take a dozen sleeping pills at once, the person dies. Similarly, an excessive amount of current at once can be fatal - 50 to 100mA, depending on the individual and circumstances.

Whether you ingest all twelve tablets simultaneously or one after the other, the fatal dose is reached at a specific time, resulting in death. Timing is crucial.

The same applies to voltage.

With low voltage, it takes more time for the current to enter the body if there is continued contact with the circuit.

At a slightly higher voltage, a greater amount of current enters the body, potentially lethal.

With excessive voltage, the current is immense, leading to burns. Death results from burns rather than ventricular fibrillation.

Never underestimate low voltage. Surge voltage, such as 1000 volts in a 230-volt tube light system, can be dangerous and cause the light to illuminate. It is deceptively simple.

Regards,

Kesava Pillai

Dear Kesava Pillai Sir,

Thank you for participating in the thread. You have provided a simple example to help understand the theory of electricity.

From your reply, it is clear that 24V cannot kill a person or induce Ventricular Fibrillation. I would like to request clarifications on the following concerns:

If the human body resistance is 1000 Ohms (in wet conditions) and 24 mA of current flows through the human body at 24V (with the heart in the circuit), how safe is a person in this scenario? How long can this current flow through the human body without causing Ventricular Fibrillation? Is 24V safe for the human body in this situation?

I am unsure if this is a foolish question. If not, I believe that asking questions is crucial for learning. Have you encountered or heard of any cases during your career where 24V has caused death to an individual?

I look forward to hearing from you soon. Thank you in advance.

Dear Mr. Dipil,

I am still unable to understand the concepts of Current, Voltage, and Ampere. Even though the Power supply is 24 Volts, if the amperage is high, it can be fatal for a person. This was mentioned by an electrical engineer, but I am struggling to comprehend it. There are many things in this world that we cannot comprehend, and this is just one of them. I look forward to hearing from our knowledgeable members.

Regarding Ohm's Law, where I = V/R (current = voltage / resistance), we can infer that current is directly proportional to voltage and inversely proportional to the body's resistance. These three factors play a crucial role in causing electric shocks to humans. Voltage represents pressure, current symbolizes the flow of electrons, and resistance signifies the stability of the human body. The minimum current required for electrocution is 10 milliamps.

For example, if the voltage is 24 volts and the human body's resistance is 100 ohms, what would be the current?

I = V/R
= 24/100
= 0.24 amps, and so forth.

Here's another analogy: Picture a water tank with its outlet connected to a pipe and a tap. The pressure inside the tank is akin to voltage, and the flow of water through the pipe is comparable to current.

Thank you.