The Killer - Amps or Volts?

[FMC1959]

I have often heard that amps are the killers, not the volts.

On the other hand, I also heard that in NA we adopted 120 volt for most items, versus 240 volt like most of the planet because it is safer if inadvertently shocked.... which is weird because all those 240 volt items are always 1/2 the amps than their 120 volt counterpart.

Any authorities out there (not "I read it on the internet") know if you get a shock from e.g....a 120 volt 10 amp grinder, or its European model that would be 240 volt 5 amp; which would be worse, or lethal, like if you dropped the grinder in a puddle of water you are standing in? (no need for all the witty comedians about standing in water with a grinder, just trying to put an example together)

Also, anyone no why in the US and Canada we adopted 120 versus 240, was it safety?

 

[MoonRise]

It's the amps through/across the heart that disrupt its beat and kill you.

It's the huge amps pushed by huge voltage in a high voltage situation (powerline, lightning, etc) that can literally cook your body tissues and cause so much damage that you die even if somehow the electricity took a path through the body that didn't include the heart.

Ohm's Law

E = I * R

(or for you young'uns, V = I * R )

The body's resistance is mostly a fixed value (subject to all sorts of variables, but 'mostly' a fixed value for any one specific incidence of electrocution).

The voltage is the 'force (hence the E for "electromotive force" in the original old-school Ohm's Law equation) that is 'pushing the electrons/electricity through the circuit (which could include your body or parts thereof).

And those two values right there determine the current that will flow through the circuit.

And the current to cause your heart to stop or have its rhythm interrupted?

About 5-10 milliamps!!!

So it's not the amps that can kill you, its the MILLIAMPS.

(if the current flowing through the body is in the amps range, there will probably also be the 'cooking' damage to the body tissues, whether or not the heart rhythm was messed up from the current through the heart).

120V-10A USA machine vs 240V-5A European machine? In a puddle?

Good chance to be dead either way.

Worse? Dead is dead, it doesn't matter there.

 

[Trey T]

Both. Neither volt or amp does the "work"; it takes both (aka VA or Watts) to do the "work" to kill.

 

[Old Man Roger]

Considering a tazer hits you with a boatload of voltage, but only a few milliamps.

Taser International says its device can deliver up to 50,000 volts in an open air arc, it does not deliver that much voltage to a person's body. The company says its Taser X26 delivers an average of 1,200 volts.

 

[CJ7VFR]

Both. Neither volt or amp does the "work"; it takes both (aka VA or Watts) to do the "work" to kill.

Considering a tazer hits you with a boatload of voltage, but only a few milliamps.

Exactly. That is also why static electricity does not kill you. When you get "zapped" in the winter when you walk across a carpeted floor, and then you touch someone or something metal, the static charge can be as high as 25,000 volts.

But there is no amperage behind that zap. If just volts could kill you, then everyone who has a carpet in their house would be dead.

Jim

 

[dogdog]

I think this subject have been beaten to death by some youtube guy...

LOL this one actually is really good...@50 sec

 

[Stuart in MN]

Plenty of people get electrocuted each year from 120vac, don't think that it's safe to touch.

 

[rlitman]

Exactly. That is also why static electricity does not kill you. When you get "zapped" in the winter when you walk across a carpeted floor, and then you touch someone or something metal, the static charge can be as high as 25,000 volts.

But there is no amperage behind that zap. If just volts could kill you, then everyone who has a carpet in their house would be dead.

Jim

That's an interesting point. 5000V static charges are not unusual (though 25,000V would be unusual). But the actual voltage across your body is still pretty low. This is because much of the voltage is spent across the arc, your body's resistance is fairly low, and the current is very limited.

 

[Old Man Roger]

Now I'm gonna complicate things..lol Can't a certain hertz stop your heart, at a very low amperage?

 

[Brian_WK]

Both can kill you but you need a certain amount of voltage to actually travel through your body.

As for the safety of the grinder example. The maximum amount of wattage that will be supplied to the tool is determined by the breaker. 120v 15A = 240V 7.5A (I have no idea what breakers in the 240V 50HZ realm are rated at). So to answer your question on the grinder the 240v has more potential but the rated amp draw of the tool has nothing to do with it.

FYI attached is a picture of me holding 2 meter leads at my desk for how much resistance is from fingertip to fingertip one in each hand.

Brian

 

[pancho400cid]

I hate this discussion. It's always the same.

It boils down to this:

Is it bullet velocity or the pressure in the gun barrel that kills you?

 

[Brian_WK]

I hate this discussion. It's always the same.

It boils down to this:

Is it bullet velocity or the pressure in the gun barrel that kills you?

Its more like is it the bullet velocity (Voltage) or the Bullet Mass (Amps) that kills you. Big bullet no speed your fine. Small bullet lots of speed your fine.

Brian

 

[CoogarXR]

The path of the charge is what kills you. If you have your arm on a good ground, and you touch a high voltage + high current source with your hand on the same arm, your arm will blow apart, but you'll probably live. You might even get the benefit of instant cauterization so you don't bleed out while you are in shock.

But, if you touch ground with one hand, and touch the same power source with your other hand, the charge will have to pass across your chest to ground and most likely kill you.

So yeah, as was said, you need BOTH voltage and current, and a critical path. Otherwise, it just hurts a lot.

-Sincerely,
A guy who has been shocked by various voltages, amperages, and frequencies

 

[tapered-pin]

I was under the impression that we use 120 (instead of 240v) here in NA because the higher amperage carries better over long distances than the lower amperage. (ie, it's more efficient to distribute from a utility standpoint)

 

[rlitman]

I was under the impression that we use 120 (instead of 240v) here in NA because the higher amperage carries better over long distances than the lower amperage. (ie, it's more efficient to distribute from a utility standpoint)

Huh? No, higher voltage is more efficient to distribute. But distribution lines are MUCH higher voltages, and transmission lines higher still.

And if you really want to confuse people, large submarine power cables are often high voltage DC.

 

[pancho400cid]

My point above is that there CAN NOT be current without Volts..... so assigning blame to one phenomenon or the other is silly.

 

[exranger06]

I have often heard that amps are the killers, not the volts.

On the other hand, I also heard that in NA we adopted 120 volt for most items, versus 240 volt like most of the planet because it is safer if inadvertently shocked.... which is weird because all those 240 volt items are always 1/2 the amps than their 120 volt counterpart.

Any authorities out there (not "I read it on the internet") know if you get a shock from e.g....a 120 volt 10 amp grinder, or its European model that would be 240 volt 5 amp; which would be worse, or lethal, like if you dropped the grinder in a puddle of water you are standing in? (no need for all the witty comedians about standing in water with a grinder, just trying to put an example together)

Also, anyone no why in the US and Canada we adopted 120 versus 240, was it safety?

The number of amps the appliance uses is irrelevant. Just because the grinder uses 5 amps, doesn't mean 5 amps will flow through you if you get shocked. What determines how many amps go through you is the resistance of your body and the voltage. You can have 5 amps going through the grinder and 11 amps going through you at the same time.

 

[Trey T]

But let's be real and forget about the fundamentals - amps do kills.

I mean ... come'on ... most of the people we know are just regular Joes and we all just need a quick a dirty info to keep ourselves safe around household electrical stuff.

 

[TRWham]

It's not the fall that kills you. It's really the sudden stop at the bottom.

 

[marinusdees]

The electrical current in the body controlling heartbeat (pacemaker) is nominally a sine wave with each part of the wave controlling a specific function. The external sine wave will disrupt the pacemaker's sine wave, depending on which segment of the external wave intersects with which segment of the pacemaker's sine wave. Thus, there is no clear answer. Or, "it depends" is the final answer. This is a gross simplification of the facts, but serves.

 

[chrismenke]

It's the volts that jolts, it's the mils that kills.

 

[Showkey]

Interesting facts and history on defibrillator devices:

https://en.m.wikipedia.org/wiki/Defibrillation

https://hypertextbook.com/facts/1999/CindyAnnRomanowich.shtml

 

[Stuart in MN]

we all just need a quick a dirty info to keep ourselves safe around household electrical stuff.

The simple answer is to shut the power off (and make sure it's off) before working on anything electrical.

 

[FMC1959]

I did not realize this was hotly debated in the past.

GJ is full of auto buffs and wondering about getting zapped by your automotive system. Many items are 12 volt and have heard that in some cases the amps can get up there, 30-50 amps or more. Yet fatalities are much more rare, as well built in safety devices against getting electrocuted (like GFCI's) do not exist or are pretty rare, I suspect because the hazards are less.

I understand many of the responses that state a combination of both is required to be deadly.

I was born here but my family is European. As kid I always heard my father and uncles say that 240 volt was more deadly than 120v we have in NA, though they might have been incorrect with their assessments.

Thing is in Europe a small radio, phone charger or smallest night light to light up a hallway at night, are all items that plug in a wall that carries 240v.
Would that be the key? It doesn't matter how much amperage an item draws, the outlet caries enough for a .5 amp charger to a 15 amp motor, so if either one has a short and you touch it, you get the maximum effect of the supply line?

Does anyone know for sure why we have 120v versus 240v the majority of countries run on?

From what I know 120v is less cost effective. If homes in NA were all wired with 240v, wiring would be so much cheaper because only half the amps are required.

 

[Mr. T]

Does anyone know for sure why we have 120v versus 240v the majority of countries run on?

Because Edison.

If you would like a more detailed explanation I’ll include a link.

www.google.com

 

[Whitworth]

I’ve never seen a “Danger: High Amperage” sign in my life.

 

[exranger06]

I did not realize this was hotly debated in the past.

GJ is full of auto buffs and wondering about getting zapped by your automotive system. Many items are 12 volt and have heard that in some cases the amps can get up there, 30-50 amps or more. Yet fatalities are much more rare, as well built in safety devices against getting electrocuted (like GFCI's) do not exist or are pretty rare, I suspect because the hazards are less.

I understand many of the responses that state a combination of both is required to be deadly.

I was born here but my family is European. As kid I always heard my father and uncles say that 240 volt was more deadly than 120v we have in NA, though they might have been incorrect with their assessments.

Thing is in Europe a small radio, phone charger or smallest night light to light up a hallway at night, are all items that plug in a wall that carries 240v.
Would that be the key? It doesn't matter how much amperage an item draws, the outlet caries enough for a .5 amp charger to a 15 amp motor, so if either one has a short and you touch it, you get the maximum effect of the supply line?

Does anyone know for sure why we have 120v versus 240v the majority of countries run on?

From what I know 120v is less cost effective. If homes in NA were all wired with 240v, wiring would be so much cheaper because only half the amps are required.

Higher voltage is more dangerous. Automotive systems are generally safe because 12v is not enough force to push the electricity through you. 120v or more is more than enough to push an electrical current through you. It's ultimately amperage that kills you, but you need sufficient voltage to push the current through. You can't really have one without the other. And the higher the voltage, the more current will go through you. Twice as much voltage = twice as much current going through you. Let's say the resistance of your body is 100k ohms. 120v divided by 100k ohms = 1.2 milliamps. 240v divided by the same 100k ohms = 2.4 milliamps. That's why high voltage power lines are so dangerous. 13,800 V (typical utility voltage)÷100k ohms = 138 milliamps

 

[Showkey]

I the maximum effect of the supply line?

Does anyone know for sure why we have 120v versus 240v the majority of countries run on?

From what I know 120v is less cost effective. If homes in NA were all wired with 240v, wiring would be so much cheaper because only half the amps are required.

Read about 10 responses down in this link you get the idea......

https://www.quora.com/Why-is-electricity-in-the-USA-110v-when-the-rest-of-world-uses-230v

 

[rlitman]

I’ve never seen a “Danger: High Amperage” sign in my life.

I can't say I've seen such a sign, but the current flowing in superconductors can easily get dangerous, even at low voltages.

 

[Copymutt]

Nichola Tessla used to amaze people by lighting up fluorescents in his hand and absorbing tens of thousands of high frequency AC volts and passing them on to ground. No amperage.
Jim

 

[FMC1959]

Read about 10 responses down in this link you get the idea......

https://www.quora.com/Why-is-electricity-in-the-USA-110v-when-the-rest-of-world-uses-230v

Thanks, and interesting that not all, but many state safety being a reason for 110 over 220.

 

[ard]

Now I'm gonna complicate things..lol Can't a certain hertz stop your heart, at a very low amperage?

zero hertz is bad news.

In simple terms, when the heart muscle is 'held' in a depolarized state it can lose its synchronized beating. A DC current is more lethal at doing this, and in a shock situation it can prevent a normal sinus rhythm from occurring

An automated defibraltor will lock onto the signal from the heart (if any) and time its delivery. It tries to hold the heart 'still' by depolarizing the entire heart muscle, so the cells in the sinus can 'restart' the natural pacing. But it does so only for a short moment.

 

[Matt Matt]

The saying goes it’s amps kill, not voltage. This is not entirely true.....

The average human skin is considered non-conductor at low voltage.

Low voltage is anything under 150 V to ground. This should burn outside of the skin and not jump through.

At 200 V to ground, the arc can jump right through the skin and attacks and travels through the nervous system and microwaves everything in its wake. Enough amperage needs to be present. Just play safe, and know what you’re dealing with.

I work with linesman guys & capacitor banks guys that are both in the above 600 range. No job is a rush and safety is for most!

 

[rick carpenter]

And if you really want to confuse people, large submarine power cables are often high voltage DC.

All this time I thought submarines were cordless.

 

[PhysicsDude]

The amps vs. volts danger thing is a dumb discussion.

Its like discussing what actually kills you, the height from which you fall, or the speed at which you hit the ground. They're related to each other.

12 volts will never kill you. 10+ amps will never run through your body unless there are thousands of volts present.

50ma can kill you if it hits you right, but its not really the current, its the voltage and its effect on your heart/nerves.

10,000V from a taser is much safer than 10,000V from high voltage power lines.

I doubt the US standardized on 120V for safety reasons. No US electrical device from 100+ years ago looks like they were concerned for user safety, hah.

I'm not sure that 120V is really that much safer than 240V. 240V is not enough to "cook" you to death.

If you google it, you'll get all sorts of explanations. The one that makes the most sense to me, is that original Edison light bulbs ran at 110 volts DC, and could also run at 110 volts AC, so they standardized on 110 volts AC so that people didn't need to buy different light bulbs. 240V became standard, like Europe, but with the split phase power distribution to the power sockets, like we know it today.

That's just my opinion though. There's probably more than 1 "correct" answer.

 

[ddawg16]

It's Watt's that matter.....

How many of us have been zapped by the ignition wire on our cars?

In a lot of cases, it's what you do after getting zapped that kills you. Like falling back..or off the ladder.

True story.....

Many years ago went to a call. Dead guy....accidental death.

It seems he had a ****** perversion.

He took a lamp cord, stripped back the ends.....stuck one end up his ***, with the other end wrapped around his pecker.

He would then proceed to ********** while he plugged the lamp cord in and out of an outlet...

Until he got to a point where he couldn't unplug it.

I'm scared for life

 

[laser3kw]

I've been hit by 20,000~ 50,000 volt magneto(s) many times - just not across the chest. I have also gotten a wake up call from a automotive car battery.

All this time I thought submarines were cordless.

da-da-dunt!

 

[CoogarXR]

I’ve never seen a “Danger: High Amperage” sign in my life.

My friend maintained a sound system for a public meeting place. He kept the sound cabinet behind a metal grate that had a sign "Danger- 10,000 Ohms!". I said, "what's up with that sign?". He said, "It keeps the stupid people out".

 

[Trey T]

The simple answer is to shut the power off (and make sure it's off) before working on anything electrical.

that's a better advice!!!

 

[TRWham]

It's Watt's that matter.....

How many of us have been zapped by the ignition wire on our cars?

In a lot of cases, it's what you do after getting zapped that kills you. Like falling back..or off the ladder.

True story.....

Many years ago went to a call. Dead guy....accidental death.

It seems he had a ****** perversion.

He took a lamp cord, stripped back the ends.....stuck one end up his ***, with the other end wrapped around his pecker.

He would then proceed to ********** while he plugged the lamp cord in and out of an outlet...

Until he got to a point where he couldn't unplug it.

I'm scared for life

So he came and went at the same time, huh?