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Steve G.
Steve G., Electrical Engineer
Category: Electrical
Satisfied Customers: 17978
Experience:  Spent 20 years as an Electrical Engineer, designing electrical plans and specifications.
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How many volts does it take to damage a human from household

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How many volts does it take to damage a human from household current?

My laptop power cable was plugged in (not connected to my laptop) and I went to unplug it. My finger accidentally touched the metal plug instead of the protective exterior. I got quite a shock from this incidental contact. My hand is still a little numb. How much damage is done to a human body from this minimal contact?

Hello there and welcome to Just Answer. My name is XXXXX XXXXX I will be assisting you today. I am an engineer with over 30 years of electrical and electronic training, repair and installation experience. I will try and answer your question accurately and precisely so that we can get you on your way.

Now..did you get a zap from the 120V side of the adapter or the 19V side that goes into your laptop?

Please let me know so that we can continue.

Regards

Steve

Customer: replied 3 years ago.

I was zapped at the plug into the surge protector--the 120V side

Ok, that's what I thought.

It is not voltage that kills you, it is current (amperage) that stops the heart. You got a zap from 120V and it was enough to prompt you to post a question here however, if you have ever received a jolt from the spark plug wire on a car or lawnmower, you may be surprised to learn that that is about 30,000 volts. But, because there is no current available, it does not make one self combust.

There is current available with house power though and as little as 0.1A can cause death. The higher your resistance, the less of a shock you will receive. Standing on a wet floor for example is going to lower your resistance to ground dramatically which is why GFI receptacles are required in bathrooms.

I hope that helps answer your questions, please let me know if you need more info. I'll be here.

Steve

Customer: replied 3 years ago.

I'm a big, muscular person. I was standing on carpet. What type of resistance would I have?

I can't answer that completely but a rule of thumb is 100 ohms from hand to hand and 500 ohms from hand to foot.

I can tell you that I am 180lbs, 6 ft and have been hit by 120V over 100 times (I'm also old) and a few times by 240V without ill effects except for the one time I bit my tongue as I jumped back.

If you got a 120V jolt for a split second, I doubt very much that you were harmed permanently.

I hope that helps answer your questions, please let me know if you need more info. I'll be here.

Steve

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