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.