Why an alternating current is dangerous than direct current?

Answer 1

because it is 2 hot leads of 277vac =480v. not 2 hot leads of 110-120vac=220vac

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The higher the voltage becomes the higher the current becomes through a set resistance.

A normal dry body's resistance from thumb to thumb is about 2.6 meg ohms.

This is the body's outside resistance from point to point and not the body's internal resistance. Once the shock has started the skin becomes burned and this starts to lower the outside body resistance to a lower value. The longer the burning continues the lower the outside resistance becomes until it reaches an inside body resistance.

The body's internal resistance is in the neighbourhood of 1000 ohms.

Using the same formula with the internal resistance and see the drastic current increase that will kill you.

The formula for amperage is Amps = Voltage / Resistance.

Using a secondary voltage of 220 the formula is, Amps = 220/2600000 = .0000846 amps or .0846 milliamps.

Using a secondary voltage of 220, the formula is , Amps = 220/1000 = .22 amps or 220 milliamps

Using a secondary voltage of 480 the formula is, Amps = 480/2600000 = .0001846 amps or .1846 milliamps.

Using a secondary voltage of 480, the formula is , Amps = 480/1000 = .48 amps or 480 milliamps

As you can see, as the voltage become higher so does the current that can flow through your body if you short across an electric potential.

The following list is the tolerances that the body can stand.

Less than 1/2 milliamp no sensation

1/2 to 2 milliamps Threshold of perception

2 to 10 milliamps muscular contraction

5 to 25 milliamps painful shock (may not be able to let go)

Over 25 milliamps Could be violent muscular contraction

50 to 100 milliamps Ventricular fibrillation

over 100 paralysis of breathing.

See sources and related links below.

Answer 2

Direct current energy for domestic use is obtained from batteries and are low voltage. Quad A, triple A, Double A, C and D batteries are commonly used in the home and are very low voltage. Older vehicles, motorcycles, mowers and ATVs use 6 volt batteries. Modern cars and trucks use 12 volt batteries. Heavy duty equipment use 24 volt batteries. Can you see the difference between 220 volts, used for dryers and ovens, and 24 volts? It's not the alternating or direct current that is more dangerous.

Answer 3

It's not. Direct current is more dangerous because it stresses the body more, the body can easier withstand an alternating current. Direct current may fx cause the heart to cook or even explode while alternating current typically won't change it's temperature or size much.