Electrocution ... who's at work ... who does the damage...?

Question

is it the amps or the volts

brief explanation would be appreciated

very interesting debate this, but most of you say amps ... inferring a conductor

do we treat the human body as a conductor or an insulator ??

interesting perspective, thomas
to say that amps does the damage, we infer the body to be a conductor
insulator & di-electric strength would be volts, correct !

Answer 1

Short Answer: "It's the volts that jolt, but it's the amps that kill."

For a given resistance, the voltage determines how many amps will flow through the person. – Basically Ohm’s Law.

The typical human body has a resistance of about 5,000 ohms. But if your skin is wet, the resistance is lower. If the resistance of your wet skin is 1,000 ohms, and you touch a 120 volt wire, the current passing through your body would be 120 volts ÷ 1,000 ohms = 0.12 amps (120 mA). This is more than enough to kill you!

Ohm's Law doesn't care what the item is. If the voltage is high enough, "everything" will conduct electricity. This could be a person, wood, glass, rubber. This is why high voltage equipment has VERY thick insulation.

The amps are doing the damage!

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Here is the water analogy for various electricity attributes.

Volts = Water pressure
Wires = Water pipes and/or hoses
Amps = Flow rate (gallons per minute)
Resistance = Objects resisting the flow of water. Friction in the pipe, etc. Measured in ohms.
Insulation/Dielectric Strength = Strength of the pipes and hoses. If the water pressure is too great, it will burst the pipes.

In the case of electrocution, the person becomes a "hose" and the electricity "flows" through their body. Anything more than 0.1 amps will likely cause death as described in the long answer below.
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Long "Technical" Answer: This answer will assume the question is related to AC power at either 50 or 60 Hz.

IEEE 80 is the standard related to substation grounding. The paragraphs below are from Section 5 of that document. The names and numbers in brackets reference the endnotes of IEEE 80 which is listed in the “Source” section below. Much of the research involved college student “volunteers” during the 1940’s and 50’s.

Humans are very vulnerable to the effects of electric current at frequencies of 50 Hz or 60 Hz. Currents of approximately 0.1 A can be lethal. Research indicates that the human body can tolerate a slightly higher 25 Hz current and approximately five times higher direct current. At frequencies of 3000-10,000 Hz, even higher currents can be tolerated (Dalziel and Mansfield [B33]; Dalziel, Ogden, and Abbott [B36]). In some cases the human body is able to tolerate very high currents due to lightning surges. The International Electrotechnical Commission provides curves for the tolerable body current as a function of frequency and for capacitive discharge currents [IEC 60479-2 (1987-03) [B83])]. Other studies of the effects of both direct and oscillatory impulse currents are reported in Dalziel [B25][B27].

The most common physiological effects of electric current on the body, stated in order of increasing current magnitude, are threshold perception, muscular contraction, unconsciousness, fibrillation of the heart, respiratory nerve blockage, and burning (Geddes and Baker [B74]; IEC 60479-1 (1994-09) [B82]).

Current of 1 mA is generally recognized as the threshold of perception; that is, the current magnitude at which a person is just able to detect a slight tingling sensation in his hands or fingertips caused by the passing current (Dalziel [B27]).

Currents of 1-6 mA, often termed let-go currents, though unpleasant to sustain, generally do not impair the ability of a person holding an energized object to control his muscles and release it. Dalziel’s classic experiment with 28 women and 134 men provides data indicating an average let-go current of 10.5 mA for women and 16 mA for men, and 6 mA and 9 mA as the respective threshold values (Dalziel and Massogilia [B34]).

In the 9-25 mA range, currents may be painful and can make it difficult or impossible to release energized objects grasped by the hand. For still higher currents muscular contractions could make breathing difficult.
These effects are not permanent and disappear when the current is interrupted, unless the contraction is very severe and breathing is stopped for minutes rather than seconds. Yet even such cases often respond to resuscitation (Dalziel [B29]).

It is not until current magnitudes in the range of 60-100 mA are reached that ventricular fibrillation, stoppage of the heart, or inhibition of respiration might occur and cause injury or death. A person trained in cardiopulmonary resuscitation (CPR) should administer CPR until the victim can be treated at a medical facility (Dalziel [B30]; Dalziel and Lee [B31]).


In all these cases, the current flowing through a person is determined by the person’s resistance and the voltage across their body. Ohm’s Law!

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As a final explanation, think about a 12 volt car battery. A typical battery can put out more than 500 amps, however a person can safely put their thumbs on the terminals without injury. This is because 12 volts divided their body's resistance does not produce enough amps to even be felt.

Answer 2

The culprit is the current. The voltage is only needed to break down the resistance of the skin. If you penetrate the skin, a person can be electrocuted with a 1.5 volt dry cell battery; 10 - 50 milliamperes through a persons heart, once it gets through the skin, causes ventricular fibrillation in the heart and causes death.


As an example, a person with dry hands can sustain the shock of an atuo spark plug voltage (thousands of volts) with no ill effects.

Answer 3

It is the amps! A few mili amps across the heart is enough to kill. Without amps people stood 6000 volts using a Wimshurst machine!

Answer 4

Actually both are at work!

But the necessary condition for electrocution is depends on ampere/current (thats the priority order).
Initiation facto is the Potential difference though!

To see a live demonstration, see the Van de Graffs generator at Science City, Kolkata.
Its PD is in the order of 5 megavolts, but the amps is in millis....so barely a shock!

Fatality may result from shocks of from 1 to 2 amperes and 500 to 1,000 volts.
However, the effect of electric shock on the body depends not only on the strength of the current, but on such factors as wetness of the skin, area of contact, duration of contact , constitution of the victim, and whether or not the victim is well grounded. The general range of disturbances include a mild tingling ,spasm of the muscles, loss of consciousness, and sometimes death. In addition, burns occur where the current enters and leaves the body. A lethal dose of electricity may paralyze the respiratory organs and damage the central nervous system; the immediate cause of death, however, is usually an interruption of heart action.

If the values are in the range quoted (which I did above) or more....thats ELECTROCUTION!

Answer 5

The body can stand any number of volts,tens of thousands with no ill effects..
The current.[amps] is what kills.
As little as 50 milliamps can be deadly,but this requires voltage.
As little as 50 volts can overcome the resistance of the skin and if there is a ground path it can be deadly.

Answer 6

It is the volts. This is the reason why we use lower voltage at home.

Imagine if we use higher voltage at home, it will be very dangerous.

The National Electrical Code governs the use of electricity and the appropriate voltage. If it is not implemented or enforced in any establishment there will be a violation and a corresponding penalty.

Answer 7

its the amps that killed the person. the amps caused breathing and heart to fail and result in brain dead.