Reciprocating Bill
Posts: 4265
Joined: Oct. 2006
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| Quote (Lou FCD @ Jan. 19 2008,21:41) | | Quote | | How much voltage or current can a human take before he is killed? |
Extremely complex answer - It depends.
From personal experience as an (obviously not too bright) electrician, I've been nailed with 120v more times than I can count. Probably 100 times with 240v. Maybe 10 times with 480v. Once with all three phases of 480v clutched tightly in my bare hand while lying on a concrete floor in a puddle of hydraulic fluid. That hurt like hell. Bounced my head between the concrete and the steel rail of the conveyor belt I was working on, just to add injury to more injury.
Worst of all though was the time I was working in a primary box. Damned PECO wired the box backwards and instead of a three phase 480v set of lines, I put my meter (rated for 600v) on a 4.5kv set of lines. It exploded.
I woke up the next day in a hospital, blind and unable to remember the incident. Apparently I kept assuming that I'd been in a car accident on the way to the job, apologizing to my buddy (the boss' son) for wrecking the truck, being corrected and having the whole thing explained to me, and returning to start. Zero short term memory. The vision took about a week to return enough to be able to function. Best anyone can figure is that my brand new boots' thick rubber soles saved my life, though at that voltage they shouldn't have. (I kept the remains of the meter as a souvenir, and still have them.)
But then there are people who bite the big weenie when they hit a bare spot in the house feed wires with an aluminum gutter. That's only 240v.
I don't recommend experimenting to find out. |
I'd heard (can't recall where) that 80-90 volts is actually the most dangerous range. Shocks in that range can induce cardiac fibrillation, while higher voltages result in cardiac "clamping": the heart simply seizes up in a single tight contraction - then resumes beating once the voltage is removed. Of course, the most serious permanent injuries induced by electric current are caused by the heating of tissues, which is a more severe problem at higher voltages.
When I was in high school some buddies and I had a device for cooking hot dogs by electrocution. The dogs were mounted on prongs which, once the lid was closed, were directly connected to the 120 volt line. The dogs were cooked from inside by the heat generated by the current flowing through them.
The thing worked, but got pretty scuzzy because we rarely cleaned it out.
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