ESD Systems - Questions And Answers

Why don't I get killed when I touch a 110V 60 hertz circuit? - David, Chino, CA

Note: Answer below may not be suitable for all audiences. You can. It is the current path. Some people could perhaps die from such contact, but in general, we have enough resistance on our shell (skin) to limit this current. Now, if you had one hand on ground and the other on 110 VAC, while both palms had deep lacerations and bleeding profusely (now you become very conductive) and you had a bad heart, there may be enough current (cause the resistance has dropped severely) to kill or stop your heart. Remember, you need over 100 mA with AC to have a fatal experience. So the fatal resistance level is approximately 1,100 ohms, very rare for people’s skin indeed. And this current needs to get inside you....to your heart and your nervous system. Current always wants to travel on the surface of conductors (due to the electromagnetic forces and repulsion) so it is a rare occurrence to have it travel inside your body. Increase the voltage and your natural resistance also decreases, putting you more at risk. I’ve heard of electricians who have died or had their skin across their chest removed when holding 220 VAC in both hands, usually why you want to keep one hand off.

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