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High-Voltage Fences For Zapping Would-Be Copper Thieves
coondoggie writes "It may be a gimmick or the ultimate answer, but a California city this week okay-ed a draft ordinance that would let businesses install 7,000-volt electric fences to protect sites from rampant copper thieves. As reported by the Sacramento CBS station, the reaction from one business owner to the ordinance says it all: 'It'll be a little fun to watch one of these guys get electrocuted holding my fence trying to rob me.'"
When I was ten (half a century ago), by buddy actually did piss on an electric fence. Poor kid lay there screaming for ten minutes, but there was no permanent damage. I think this is an excellent idea; farmers and ranchers have been using electric fences to keep their animals in for decades, and I have yet to hear of anyone being harmed.
Free Martian Whores!
I'm not a licensed electrician, but 7,000 volts sounds kinda' deadly.
Not really, as they say "current kills", not voltage. Static electric discharges frequently have a higher voltage than that. Lethality depends on a number of different factors. Of course, 7,000 volts of continuous DC current would most certainly be enough to kill most people, but electric fences usually use short pulses rather than continuous flow (at least, animal fences I've worked with, and been shocked by, do).
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
They tested pissing on an electric subway rail and that failed. They then tried the electric fence and it did work. Perhaps you should have watch the WHOLE episode before commenting here.
The busted the third rail, but found electric fence plausible. http://en.wikipedia.org/wiki/MythBusters_(2004_season)#Peeing_on_the_Third_Rail
BTW, if you ever need to determine if your electric fence is switched on or not, without putting your tongue across it, a portable AM radio tuned between stations and held close to the wires will enable the HV pulses to be heard.
Yeah, people keep saying that, but its not true. Have a read of ohms law. E=I*R and P=E*I (e=voltage, i=current, r=resistance, p=power) If you want to put 50ma through a person who has 2ko of body resistance, you need 100V. That'll pull 5 watts from the fence. If your electric fence is 10kv but can only deliver 1 watt, the voltage will drop to 45V and the current will be 22ma with a 2k load.
You're pretty safe with anything less than 30ma. Most RCD safety devices wont trip until there is a 30ma leak.
I once touched an electric fence with a three foot stick. I got quite a jolt. It's current, amps, that are dangerous, but it's volts that jump through insulation, and these things have a lot of volts. If you're unsure whether gloves, say thick leather work gloves, will help, consider this - an electric fence is designed to drop a 2,000 bull. A bull covered in non-conductive hair, and under that, covered in leather. Hmm, I'm giving advice for THIEVES. Come to think of it, everything I just said is a lie. All you have to do is use your T shirt to cover the wire, so your hands don't touch it directly. It'll work, I promise.