I will explain, AC or DC voltage, which is a more dangerous electric current to the human body, in this post. Many factors decide the intensity of electric shock on the human body. These other factors also play a vital role in addition to DC or dangerous AC frequency.
In this post, I will explain all these like AC or DC, which is a more dangerous frequency of the electric current on the human body. Further, I also will discuss in detail the other factors affecting the intensity of electrical shock to the human body.
The content of the article is as follows
AC or DC which one is more dangerous to the human body
The AC current of 50 to 60 Hz frequency is the most dangerous. Further, DC is more dangerous than AC of higher frequencies to the human body.
The electrical resistance of the human body
First, we will discuss the resistance components in the electrical circuits. These resistor components limit the current flow in the human body. Please refer to Fig 1.
In addition to the inside body resistance, skin resistance appears 2 times in the circuit model. One resistance indicates the touching point of a conductor by the body. Another resistor indicates the resistance between the feet and the earth’s touching point.
Skin resistance will depend on various conditions like dry or wet skin and sweating. The skin resistance of wet hands is very less. So, if the wet hand touches the live wire, then more electric current flows.
Further, the value of the skin touch resistance itself changes. It goes down with continued contact and the burning of the skin. So touching longer time the live wire is more unsafe.
Then the current flowing in the body will depend upon this equivalent resistance. This current also depends on the voltage level of the DC or AC supply.
Voltage or current (AC or DC), which one is more dangerous
The flow of electric current in the human body decides the intensity of the electric shock. This is applicable at the voltage level available at the homes. However this current depends on the voltage level, as current flow is equal to voltage divided by current.
But, if the voltage level is very high. Then the high voltage applied for a short time also creates harm to the human body.
Effect of the parts of the human body touching the live wire and earth
The path of the current flowing in the body is also important. It depends on touching parts of the body with live wire and earth.
One possibility is that the hand touches the live wire, and the feet are is touching the earth. So current flows from hand to legs.
In the second possibility, one hand touches the live wire, and another touches the earth or neutral wire.
In the second case, current flows from one hand to another hand through the heart. Here more current flows through the heart compared to 1st possibility. So for the AC or DC, this kind of possibility is more dangerous.
Effect of the Frequency of AC or DC, on the Male and female body
Now, we will discuss AC or DC electricity which is more dangerous frequency to the human body
As indicated in Fig 2, the male body has better resistant to electrical shock as compared to the female body. Further, the body is less resistant to electrical shock at frequencies around 50 to 60 Hz of AC.
AC or DC which is the more dangerous frequency
Now, let us see Fig 3. Fig 3 shows the danger zone of electrical current limit in the human body vs frequencies.
The high-frequency current is most safe. The 50 Hz or 60 Hz current range is most critical or unsafe.
And DC current is safer than 50 or 60 Hz Ac currents. But DC current is less safe than high-frequency current.
Let through current vs time in the human body.
Let through current is the safe limit of the current flow in the body. If this current flows in the body and then if we remove the current. Then the person may be able to recover from the dangerous effect of the electrical shock.
Factors affecting the danger of AC or DC electrical shock
There are many other factors, which affect the danger of AC or DC electrical shock to the human body, which are as follows:
- DC offset of waveform DC or AC:
- Percent of ripple current
- Hand-touching pressure
- The health of the person
- Area of conductor
- Age of the person
- Mass of the person
- Dry or wet hand
- Sweating
Note: As the intensity of electrical shock depends on many factors. So it changes from person to person. Thus the value of Fig. 2 to fig. 4 is typical or average values only.
Electrical safety to human precautions & discussion
It is our responsibility to be safe regardless of AC or DC which is more dangerous, There are rules and precautions to avoid accidental risk. Some interesting points and precautions are as follows:
- Plugs and sockets at home are of IP20 class. This means the space available to touch the live wire is less than finger size. So the finger will not touch the live wire by mistake.
- All home electrical appliances follow safety class.
- RCCB breakers at home.
- In some labs, we have to keep one hand in our pocket. So two parts of the body may not touch live and neutral wires together.
- Two people are a must to work on risk areas.
- Only licensed people can work in high-voltage areas.
- Get a licensing system before entering HV areas in some organizations.
- HV areas like the electricity board or HV lab have well-defined safety rules.
- Thick rubber mats are installed on the floor in the risk working area.
Summary
As discussed above 50 Hz AC electric current is the most dangerous for the human body.
But, the intensity of electrical shock on the human body depends on so many factors. It depends on frequency, time, the man or woman’s body, and touching pressure on the conductor.
It also depends on the mass, age, and health of the person. Further, it also depends on the area of the touching point, a ripple in the current, etc.
The working person follows safety rules.
Further, for a detailed discussion on AC or DC which is more dangerous, please watch the below video
I hope that you enjoyed reading this article on “AC or DC which is more dangerous“.
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Further read, why 30 mA RCCB is used in the home.
About the author – G K Agrawal B.Sc and B.Tech (from HBTU Kanpur), Retd. Sr DGM Design (BHEL), the inventor of patents, has lifelong industry experience in the electrical and electronics design field of R&D. He worked for BHEL. He shares his experience and knowledge on blogs and YouTube. Read the profile here.
