Dangers of amperage

[Toke]

The mandatory household earth-fault relay cuts the power at 50mA leak current, a house's earth connection must have low enough resistance to prevent more than 50V standing voltage on any appliance.
(so if your stove have an insulation error it will cut the power before it reaches 50V difference to ground)

One example from trade school on dangerous currents involves car batteries.
The voltage is nowhere strong enough to kill* anyone, but the amps available can easily start fires and kill people that way.
The example is a wire from the car to lights and assorted 12V appliances in a trailer/caravan, just a regular extension cord, without fuse, and just waiting for a short circuit to burst into flames along its whole length.


*but can be unpleasant depending on where you insert the wires

 

[TheReddish]

I would not be to sure you cant die of shock from a car battery, I have had a few nasty nasty shocks from bad wire harnesses and have welded a few screw drivers in my day esp with dual 12v systems.


My last 12v oops was from a 1000w corsair psu and I think by the feel of it I drew about 60amps, hurt like hell and it realy like I said is winning the Lotto, the heart could could stop from a bad sneeze let alone a 12v 60amp shock.

I bet I could find at least one case of someones pacemaker quiting from a 9v battery.

 

[Cyparagon]

^That's not the 12V rail, that's the voltage doubled mains. I've been bit by that, too. I was touching a heat sink to see if it was warm, and my thumb brushed the case.
It felt like my hand exploded :yabbem:

 

[Toke]

Some UPS units have 36 12V batteries in series, that is +432V.

 

[TheReddish]

Some UPS units have 36 12V batteries in series, that is +432V.

ouch
yep and i bet you could convince it to bite you

another way is a large RF feild, I have had my hair stand up and felt like I was being microwaved before, or the joy of a direct blast of intermittent wave looking into a wave guide

 

[Seoul_lasers]

Well been hit with allot of juice in my day, if it take electricity Ive probably worked on it, I would agree with the W being the danger though, unless its multi phase AC I would say most big AC jolts will knock you back but a strong DC charge hurts, as its hard to let go.

my close calls though, a 4 phase heating circuit, I locked out my box but a practical joke played om me about did me in.

I will tell you that a low amp very high volt jolt can still kill you though, in my teenage years I was soldering a large lead to an antenna for an old friends Ham repeater station, he turned off the radio, but his computer kicked it back on for station identification, low amps but it still put me though a good portion of his drywall and left a hole in my thumb, the shock was not that bad but my head bouncing off a stud sure hurt.

I tend to think of it like water, a small steam moving fast not that scary, a large river moving slow is just as safe, but a large river moving fast is gonna suck.

No way to predict a fatal shock though as its hard to predict the path of current in the body and the resistance of the skin.

Its kinda like winning the lotto but if you win you die.

But in no way a laser driver is gonna do you in imo.

4 phase heating? Not 3 phase?
3 phase is incredibly dangerous because of the extremely high currents and large magnetic fields around the wires, especially in large industrial sites. I saw an accident while working in dockyard here in Victoria. It was workman cutting a cable lying parellel to a hot 1020 3 phase circuit for a massive 100HP winch motor. Outcome was particularly nasty and messy. Worker survived, but was burned severely. The flash from the explosion gave him a perma-tan and 2 left fingers. Lucky he wasn't incinerated!

 

[TheReddish]

you are right it was 3 phase I had gotten 4 phase in my head thinking helicopters.

I was on a ladder to make it even better, Took me 30 min to get off the ground, kinda felt like I donated blood 4 times in one day. I stayed kinda dazed for a week.

Think I was only like 18 though so its been some time ago.

Not to much flash I was installing the heater and grabbed a handfull of ugly. fun times