Is getting shocked worse on load side?

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K8MHZ said:
The difference in current would be negligible.

If a person has a 1000 ohm resistance, line to neutral on a 120 volt circuit, they would draw .1200 amps. A load that draws 5 amps would be 24 ohms. In series, that gives us 1024 ohms or .1172 amps.
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But many will tell you they can tell the difference, plus you don't want to get nailed by "two twenty", cause it really hurts, and don't even get started with "four forty", but anything on a 15 amp fuse or breaker shouldn't hurt you all that much.:happyyes::(
 
K8MHZ said:
The difference in current would be negligible.

If a person has a 1000 ohm resistance, line to neutral on a 120 volt circuit, they would draw .1200 amps. A load that draws 5 amps would be 24 ohms. In series, that gives us 1024 ohms or .1172 amps.
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Yes, but change that resistance to a more realistic number say 100,00 ohms for a dry human body and then how do the numbers work out?
 
The reason many say getting hit from the load side of a neutral hurts more then if you just got hit from the 120 volts feeding the load is only when you are contacting the load side neutral and ground or the line side neutral on an inductive circuit, it was very common when a person changed out a magnetic ballast when the circuit was still hot, some would think opening the neutral first was safer then opening the hot, of course we know this was a big mistake, I have even been told to do it this way years ago by a boss who had no clue, but it really doesn't matter as the inductive kickback will happen on both sides of the circuit not just the neutral side.

These inductive kickbacks can be as high as few thousand volts and be as high as a half of an amp and can hurt very badly, open the conductors feeding several ballast and the current can be even higher, open the neutral of a multi-wire 277 volt circuit and if you get between the neutrals of ballast being fed from two or more circuits and you will have 480 volts (minus the VD across the loads) hitting you on top of the inductive kickback.

Also the voltage flowing through a load from a hot will be the percentage of the difference of your impedance and that of the load, heres an example:

Lets say your body's resistance is around 1k ohms, and you open a neutral of a ballast that is 100 watts and line voltage is 120vac.
this will give you a 12.6% VD across the load and 87.4% VD across you so with a 120 volt supply you will still receive a 104.88 volt shock, which percentage wise your body will hardly tell the difference, current wise the 104.9ma of current will cause 91.6ma's of current to flow through your body which is enough to kill in the right conditions, and this is not even taking into account of the inductive kickback which only last a few micro seconds, which will more likely hurt more then it has a chance to harm, trust me open a neutral to a ballast and happen to be touching the neutral that goes to the load and it will hurt, been their done that.

But this statement does come from old timers and was the result of opening the neutral on inductive loads, over the years I have heard various similar remarks but they all seem to revolve around ballast changing when magnetic ballast were the norm.

Even a high capacitance circuit can have the same effect as you can spike a cap and get it to charge up in the neighborhood of a couple thousand volts by scraping the supply voltage across the caps terminals, of course we are talking about bi-poler caps without the drain resistor, in many older color CRT TV's the output of the fly-back was doubled or tripled or even a quadrupled by this theory by using electrolytic caps and diodes to get the 25kvdc to 35kvdc to the second anode (the wire that hooked to the side of CRT) from the 9kv from the fly-back transformer.
 
infinity said:
Yes, but change that resistance to a more realistic number say 100,00 ohms for a dry human body and then how do the numbers work out?
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The current will be lower but the percentage of voltage flowing across the body will be higher.

In my example of a 100 watt load which is 144 ohms with a body resistance of 100,000 ohms you will drop 99.9% of the voltage across the body and only .1% across the load, but total current will only be 1.1ma so I don't think this is a realistic value since we know that the current should be much higher if your placing 120 volts across a body, I would say 5k ohms in more closer to the norm.

120 volts can easily cause 20ma's of current to flow across the heart, which is about 6k ohms just in that path but we also must consider that the body will also have parallel paths around and away from the heart which will mean that the total resistance will be much lower to get 20ma's of current across the heart which is considered the level that causes the heart to go in to fibrillation, so 1k ohms is not too out of line, I have measured 500 ohms from fingertip to finger tip at a time when I was wet and sweaty, but add internal high moisture from sickness or fever and I think it could be even lower, of course dehydration can go the other way.
 
My last post was lacking some of the information in my head and I was thinking about a small load. For a small load, say getting hit off of the neutral of a ballast the maximum current will be limited to the current of the ballast, so for a .25 amp ballast that would be the maximum current that the body in series with the load could be subject to. If you went on the line side of the same ballast the only limit besides the resistance of the body would be the resistance of the conductors. Either way you may end up dead but the line side contact has a higher current flow potential through the body.
 
hurk27 said:
The current will be lower but the percentage of voltage flowing across the body will be higher.

In my example of a 100 watt load which is 144 ohms with a body resistance of 100,000 ohms you will drop 99.9% of the voltage across the body and only .1% across the load, but total current will only be 1.1ma so I don't think this is a realistic value since we know that the current should be much higher if your placing 120 volts across a body, I would say 5k ohms in more closer to the norm.

120 volts can easily cause 20ma's of current to flow across the heart, which is about 6k ohms just in that path but we also must consider that the body will also have parallel paths around and away from the heart which will mean that the total resistance will be much lower to get 20ma's of current across the heart which is considered the level that causes the heart to go in to fibrillation, so 1k ohms is not too out of line, I have measured 500 ohms from fingertip to finger tip at a time when I was wet and sweaty, but add internal high moisture from sickness or fever and I think it could be even lower, of course dehydration can go the other way.
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500 - 1500 ohms is typical for a skin to skin contact. 100K ohms would more likely include clothing or footwear.
 
don_resqcapt19 said:
Yes, in both cases you are the load, and in both cases the supply voltage drives the current through the load. There will be no difference in the shock.
I have often been told the shock from an open neutral hurts more, but I think that is only because many think that you should not be able to get shocked from the white wire. It is the same as getting shocked from the hot...the voltage drives the current though the load...you.
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Yes the open neutral would hurt more because then you are in the return path of current, not just the conductor to ground.
 
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