Electric Fence Question

[jmh226]

How do I calculate the amperage of the shock received from an electric fence with the following specs?

 

The controller specs:

Voltage: 12 volt DC operated

Current Draw: 0.067 Amps

Output Pulse period: 1.280 Seconds

Pulse On Time (Electricity flowing): 0.000072 Seconds

Time between pulses (Off Time): 1.279 Seconds

Peak Output Voltage (No Load): 11,400 Volts

 

 

Fence Load Peak Volt Pulse Energy

(In Ohms) (in Volts) (In Joules)

2,000 6,560 0.27

500 5,040 0.57

300 4,160 0.60

200 3,360 0.58

100 2,160 0.49

50 1,200 0.34

 

I tried converting the Pulse energy in Joules to Watts by dividing by the pulse on time, and then using Watts=Volts x Amperage to get the amperages, but the amperages come out anywhere between .57 and 4 amps depending on the resistance. I also tried using Ohm's law (dividing the voltage by the resistance) and the amperages come out even higher! Everything safety related that I have read indicates that an amperage this high would be enough to stop the heart and cause severe burns, so I think I am making a mistake somewhere... any help would be appreciated. Thanks!

[tvp45]

You would have to know something about the impedance of the shockee (?) and the output impedance of the fence unit.

[jmh226]

I found a chart for the electrical resistance of human contact points in the safety chapter of an online document entitled "lessons in electric circuits". It indicates that a wire touched by a finger results in 40,000 to 1,000,000 ohms of resistance dry, and 4,000 to 15,000 ohms of resistance wet; a wire held by a hand resluts in 15,000 to 50,000 ohms dry, and 3,000 to 5,000 ohms wet.

 

The basic question that I'm trying to get at here is worst case scenario, what is the maximum voltage/amperage shock that one could receive from this fence. I am attempting to use electric fencing in a nature preserve, but our insurance company is balking...I want to be able to indicate to them that the maximum shock is not going to kill/harm humans.

 

Thanks a lot!

[Mr Skeptic]

Well, the easiest thing to do would be to contact the company you want to buy the fence from, and they should have a very good writeup explaining why their fence is safe (or why it would fry intruders, as the case may be). Why do the work yourself when someone else already did it for you? If anything, you can double check their report.

[jmh226]

I actually tried just that initially, but no one has the exact info that I'm looking for. Contacting the company is how I got the information that I posted above. The company basically gave me the above info and then indicated that their product is safe since it is UL listed (Underwriters Laboratory). I tried to find out what the specific UL specs are, but they want $979.00 for a copy of their specification 69 which pertains to electric fences. Not happening. So anyway, here I am trying to slog my way through figuring it out - hopefully with your help!

[Moontanman]

I've been shocked by an electric fence, it's not something I would do for recreation for sure. It hurts! I saw a pig killed by an electric fence, but it had been modified to give a huge shock by the owner because the pig had learned to resist the effects of the fence and consistently got out. he didn't get out anymore, he didn't go anywhere else again it dropped him like a sack of potatoes but that was 42 years ago, I am sure they have fails safes now to prevent that from being done.