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If my voltage applied is 170v and my resistor is 1M Ohm then my current is what? Only 0.00017 what unit is this measurement?

Pommie

Well-Known Member
Most Helpful Member
#21
When we had horses with an electric fence I would touch it to test if it was working - slight shock but not too painful. One day I accidentally touched it when my bare feet were in mud, never again, worst shock I've ever had in my life and I've had a few. If I remember correctly, in the UK voltages over 50V are not allowed in stables as they can be fatal to livestock. Different conditions (especially wet ones) can result in very different outcomes.

Mike.
 

JonSea

Well-Known Member
#22
Cut skin will also vastly lower resistance.

This is a good topic to avoid experimenting with, particularly when math isn't your strong suit!

Shocks can have some very different effects. A shock may cause your muscles to contract, clamping your fingers to the source and reducing the resistance. But shocks often also result in elbow damage when you reflexively jump back from the source and ram your elbow against something.
 

Tony Stewart

Well-Known Member
Most Helpful Member
#23
The effects of milliamp 60 Hz current flow through a person were first established by Charles Dalziel, who most importantly determined that 99.5% of the population is able to let go of a conductor sourcing 6 mA or less. Tests revealed that on average, perception of current sets in at around 1.1 mA for men, and 0.6 mA for women, pain is first experienced at 9 mA and 6 mA (men and women), and inability to let go at 16 mA and 10.5 mA [1]. Based on this data, current UL standards require "shock prevention", a guarantee that the smallest current which results in the GFCI taking action is "not below 4 mA, and not above 6 mA". In order words, the tripping threshold is set at 5 mA and the system must have milliamp resolution. Shock prevention implies very little possibility of a person becoming 'stuck' on a line, unable to let go. Elsewhere, in places like Europe, the tripping threshold is concerned only with electrocution, and so the threshold is relaxed to 30 mA and higher [2]. This is acceptable, as prolonged current flow at lower levels decreases the body impedance, which in turn increases the fault past the 30 mA threshold. Kouwenhoven and Milnor state that currents 50 mA and less "usually have no serious results, though they may be very painful and may result in temporary loss of consciousness" [3].
 

Nigel Goodwin

Super Moderator
Most Helpful Member
#24
When we had horses with an electric fence I would touch it to test if it was working - slight shock but not too painful. One day I accidentally touched it when my bare feet were in mud, never again, worst shock I've ever had in my life and I've had a few. If I remember correctly, in the UK voltages over 50V are not allowed in stables as they can be fatal to livestock. Different conditions (especially wet ones) can result in very different outcomes.

Mike.
Back when I was a kid we used to go 'beating' for pheasant shooters on a local estate, at one point we had to beat through a field of kale, which cattle absolutely love. So the farmer used to put an electric fence across the field, and allow the cattle to eat up to it, and then move the fence further back every day. However, the cattle love kale so much they weren't impressed by the electric fence, so as it wasn't very far from the farmhouse he ran a mains extension lead to the field, and connected the live wire directly to the fence!! :arghh:

As you can imagine we weren't too keen on climbing under, or over, a live mains electric fence in the pouring rain!.
 

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