Direct current (DC) or AC

[REZANIKPAYAM]

Which are more dangerous : Direct current (DC) or AC ? Why?

 

[daveede]

Afaik DC is safer because AC affects the heart more, so you can take larger DC currents than AC before you get negative effects or death.

 

[philipb]

Dc is more dangerous,have you seen the film the green mile?dc to the
electric chair,2200 volts ouch! dc is constant,ac goes through zero 50
time a second.

 

[Des 56]

Its current flow that kills, and if it's high enough, DC or AC who cares

This is what I read on the subject

If you happen to survive a shock itself then DC can be more dangerous.
DC current can cause elecrolysis of body fluids which can be poisonous.
Survive the DC shock and die of poisoning

 

[Engineer54]

Both are dammed dangerous, as to which is more, ....Pass, One has a tendency to hang on to you and the other has a tendency to throw you off

 

[Guest123]

DC is the greater of 2 evils IMO as 1. there is no "knock back" or "let go" reflex that you would get with AC. Also, greater internal heat is created with direct currents as oposed to AC so your insides will cook faster.

 

[millwall ken]

Dc is more dangerous,have you seen the film the green mile?dc to the
electric chair,2200 volts ouch! dc is constant,ac goes through zero 50
time a second.

Correct my friend, you beat me to it.

 

[daveede]

In the regs you always seem to be allowed more DC voltage Than AC on for example ELV and LV power bands so does this point to DC being safer?

 

[millwall ken]

DC is the greater of 2 evils IMO as 1. there is no "knock back" or "let go" reflex that you would get with AC. Also, greater internal heat is created with direct currents as oposed to AC so your insides will cook faster.

Any Fireman from the 50s - 70s would confirm this mate. Hence the reason that they would feel their way around buildings using the outside of their hand as opposed to feeling their way around with the palm of the hand facing the wall.

 

[Des 56]

I think its because the levels permitted in AC is Rms values,the peaks would be higher

 

[sparkiegaz]

stick your tonge in a socket then go and put it onto a 750v dc live rail out on track and make your own mind up ,,,,,,

 

[millwall ken]

I think its because the levels permitted in AC is Rms values,the peaks would be higher

THATS it, spot on Des mate, thanks, I couldn't remember the exact reason why as I'm on my 3rd (large) glass of red.

 

[Des 56]

THATS it, spot on Des mate, thanks, I couldn't remember the exact reason why as I'm on my 3rd (large) glass of red.

I'm just partaking of that vile geordie habit of guzzling a couple of bottles of Nuclear brown ale
My posts will start getting slurred soon

 

[millwall ken]

I'm just partaking of that vile geordie habit of guzzling a couple of bottles of Nuclear brown ale
My posts will start getting slurred soon

You're still a fountain of knowledge mate.

 

[MarkieSparkie]

In the regs you always seem to be allowed more DC voltage Than AC on for example ELV and LV power bands so does this point to DC being safer?

Hi dave, If you wish to compare AC and DC values, then you need the AC peak to peak value. Multiply the AC rms by 2.828 to get the equivalent AC peak to peak and you will see they are similar to DC values in the Regs. For example ELV, 50Vrms x 2.282= 141Vpeak-peak similar to the 120Vdc quoted in the regs. The DC values tend to err for safety on the low side because of the potentially more dangerous effects mentioned by others in earlier posts.

 

[Geordie Spark]

I'm just partaking of that vile geordie habit of guzzling a couple of bottles of Nuclear brown ale
My posts will start getting slurred soon

Good Lad !!

Nice to see you've got your priorities in order.

 

[REZANIKPAYAM]

How AC affects the body depends largely on frequency. Low-frequency (50- to 60-Hz) AC is used in US (60 Hz) and European (50 Hz) households; it can be more dangerous than high-frequency AC and is 3 to 5 times more dangerous than DC of the same voltage and amperage. Low-frequency AC produces extended muscle contraction (tetany), which may freeze the hand to the current's source, prolonging exposure. DC is most likely to cause a single convulsive contraction, which often forces the victim away from the current's source.

 

[Guest123]

How AC affects the body depends largely on frequency. Low-frequency (50- to 60-Hz) AC is used in US (60 Hz) and European (50 Hz) households; it can be more dangerous than high-frequency AC and is 3 to 5 times more dangerous than DC of the same voltage and amperage. Low-frequency AC produces extended muscle contraction (tetany), which may freeze the hand to the current's source, prolonging exposure. DC is most likely to cause a single convulsive contraction, which often forces the victim away from the current's source.

Why not just post a link to the whole article. TBH I feel that article is flawed as it contradicts itself on more than one occasion.

At th'end ot'day they're both dangerous but in slightly different ways.

 

[SW1970]

All electricity is dangerous and should be treated with respect at all times. I was surprised to be told this by my 7 year old who was taught this at school. (But my 10 year old was not). Fab! Just the way things should be. So in 15 years or so there'll be a generation who may be a little less inclined to go and buy a B&Q consumer unit and have a go themselves.

 

[baldsparkies]

I saw the results of a 250v dc burn, following an electric shock.
He came out of hospital minus 2 fingers and his big toe, apparently the shock current path arked in and out of his body at those points.
I agree ac can be just as dangerous, but the burns from this dc shock were horrific to say the least.
Not a pretty site and one I won't forget in a hurry.
I think we can all be guilty of taking electricity for granted working with it as we do, but this kind of thing is a wake up call, and reminds you of the dangers that lurk if you take the stuff for granted.

 

[Johnny-G]

AC/DC, it's all the same to me.

 

[IQ Electrical]

AC/DC, it's all the same to me.

You're on a Highway to Hell....