[__ Science __ ] When Does Electrocution Become Fatal?

[HeIsRisen2018]

Sorry for taking over the science section but I feel like this is a very important question that my mother and I were just discussing for too difficult of reasons to get into, but does somebody know the answer to this?

 

[jasonc]

Sorry for taking over the science section but I feel like this is a very important question that my mother and I were just discussing for too difficult of reasons to get into, but does somebody know the answer to this?

Burns,is what kills you in this. Low amps is deadly but people do loose limbs from electrical burns.

 

[HeIsRisen2018]

Burns,is what kills you in this. Low amps is deadly but people do loose limbs from electrical burns.

Oh okay, thanks for letting me know, I really appreciate it. What is an amp again though? A low shock?

 

[jasonc]

Oh okay, thanks for letting me know, I really appreciate it. What is an amp again though? A low shock?

Amperage is the amount of electrons ,the voltage is the pressure.

 

[Bull of the Woods]

I thought the word "electrocution" means killed by electric shock.

 

[Razeontherock]

I thought the word "electrocution" means killed by electric shock.

Well that doesn't sound like any fun at all!

 

[Edward]

It's amps that kills for the most part. Generally the lower the voltage, the higher potential for amps exists. The most deadly voltage is 277 so be careful around it.

 

[jasonc]

I thought the word "electrocution" means killed by electric shock.

https://www.mayoclinic.org/first-aid/first-aid-electrical-burns/basics/art-20056687

 

[WIP]

I thought the word "electrocution" means killed by electric shock.

This is correct. Our muscles can be triggered to react by the use of electric shock. Since our heart is a muscle it can be triggered by electric shock. A defibrillator uses a controlled electric shock to do its job. Typically when a person is exposed to lethal levels of electric current, it will result in cardiac arrest because the electric current interrupts our heart's ability to function properly and this is usually the cause of death from electrocution. At extremely high levels of current, we can be burned to death.

 

[WIP]

It's amps that kills for the most part. Generally the lower the voltage, the higher potential for amps exists. The most deadly voltage is 277 so be careful around it.

I'll have to disagree with you here. With a constant load, in order for the higher current one must apply a higher voltage. This is explained by studying Ohm's Law. E=IR or Volts = Amps x Resistance. Let's put it to real numbers.

Let's assume a constant load of 1000 ohms and let's see what happens to current (amps) when the applied voltage goes lower. For simplification, we'll assume direct current. It works similar with ac voltage but there are other factors that come into play that can add complexity to the math.

90v = A x 1000 ohms. Solve for Amps (A).
90 / 1000 = .09A

Now lets see what happens to the current when we lower the voltage to 50v. As can be seen, the amperage across the load will go down.
50v = A x 1000 ohms.
50 / 1000 = .05A

 

[HeIsRisen2018]

This is correct. Our muscles can be triggered to react by the use of electric shock. Since our heart is a muscle it can be triggered by electric shock. A defibrillator uses a controlled electric shock to do its job. Typically when a person is exposed to lethal levels of electric current, it will result in cardiac arrest because the electric current interrupts our heart's ability to function properly and this is usually the cause of death from electrocution. At extremely high levels of current, we can be burned to death.

That's a very good explanation thanks! And even though being a believer I don't fear death, I don't want to die by being electrocuted either. I prefer old age if I get the choice to pick. :yes

 

[JohnDB]

Your skin has a lot of resistance.
Electricity gets absorbed or blocked by your skin.

But what happens when you have a scrape or cut that removes your skin?

It only takes 0.05 amps to kill you by stopping your heart. And depending upon where the juice starts and stops you could be in serious trouble.

1 volt is all that's needed to push 1 amp across a conductor. And that's why we double and triple ground everything in an operating room from the lights to the x-ray reader and all plugs. Static electricity can kill you there...(cell phones are not allowed)
Even the floor is grounded.

GFI work by reading inbalances between the hot and neutral...and they trip at 0.03 amps these days...(used to be 0.05)

 

[WIP]

Your skin has a lot of resistance.
Electricity gets absorbed or blocked by your skin.

To a point. From my understanding there is more.

• It's the dead cells on the outer surface that provide the insulating value. However, when the outer layer is wet, resistance goes down.
• Also, as you mentioned, a cut or abrasion will also lower the resistance of the skin.
• When an electric shock occurs and causes the skin to burn at the point of contact, the resistance drops.
• Also, with ac current, our skin acts like a capacitor and the resulting capacitance lowers the impedance.

I know when I've measured the resistance using a VOM by pinching the probes, one in each hand, my body's resistance was quite high and approaching 100K ohms but the tighter I gripped the probes, the lower my resistance became.

 

[WIP]

I remember one time, it only took one time , I was working on the batteries for my tractor. I was cleaning the battery clamps and checking the electrolyte levels. I was not wearing a shirt and it was a hot summer day. The battery compartment is just under the floor so I had removed the floor plate so I could access the batteries. I was standing on the ground reaching over the frame of the tractor cab which was about chest high. When I made contact with the positive post on one of the batteries I got what felt like a bee sting under my arm. Looking around I couldn't see any bees or nest so I proceeded to do it again. It was a pretty strong sting for sure. Turned out I was getting bit by a 12v electric shock through the hairs in my arm pits. Not a very pleasant feeling.

 

[HeIsRisen2018]

I remember one time, it only took one time , I was working on the batteries for my tractor. I was cleaning the battery clamps and checking the electrolyte levels. I was not wearing a shirt and it was a hot summer day. The battery compartment is just under the floor so I had removed the floor plate so I could access the batteries. I was standing on the ground reaching over the frame of the tractor cab which was about chest high. When I made contact with the positive post on one of the batteries I got what felt like a bee sting under my arm. Looking around I couldn't see any bees or nest so I proceeded to do it again. It was a pretty strong sting for sure. Turned out I was getting bit by a 12v electric shock through the hairs in my arm pits. Not a very pleasant feeling.

Well I'm so glad that you survived to tell the tale, but next time you should definitely wear a shirt. :yes My mother told me that being electrocuted wasn't a very pleasant feeling, but more than likely I would survive from it so that's good. Your story has reassured me about that. :biggrin

 

[JohnDB]

The biggest problem with juice is usually getting held...or knocked off the ladder from muscle spasms. I've had both happen to me.
Feels bad every time.

 

[Bull of the Woods]

The question should be what kind and amount of electric shock is fatal.

The term "electrocution" means a fatal shock. There are no degrees of electrocution. If you receive enough of an electric shock to be killed than you have been electrocuted.
If you aren't dead you haven't been electrocuted. Just shocked or burned.

 

[Edward]

I'll have to disagree with you here. With a constant load, in order for the higher current one must apply a higher voltage. This is explained by studying Ohm's Law. E=IR or Volts = Amps x Resistance. Let's put it to real numbers.

Let's assume a constant load of 1000 ohms and let's see what happens to current (amps) when the applied voltage goes lower. For simplification, we'll assume direct current. It works similar with ac voltage but there are other factors that come into play that can add complexity to the math.

90v = A x 1000 ohms. Solve for Amps (A).
90 / 1000 = .09A

Now lets see what happens to the current when we lower the voltage to 50v. As can be seen, the amperage across the load will go down.
50v = A x 1000 ohms.
50 / 1000 = .05A

By your numbers it looks ok but something else is coming into play here and I'm not sure what yet.

My 240v window shaker pulls half the amps of the 110v window shaker. Lower voltage higher amps.
It's always cheaper to run a 240v appliance over a 120v appliance. ..so who went wtong here, lol

 

[JohnDB]

By your numbers it looks ok but something else is coming into play here and I'm not sure what yet.

My 240v window shaker pulls half the amps of the 110v window shaker. Lower voltage higher amps.
It's always cheaper to run a 240v appliance over a 120v appliance. ..so who went wtong here, lol

You have a watt meter on your service entrance.
Half the amps on each of the two phases...equals twice the amps on a single side.
You save nothing.

 

[jasonc]

You have a watt meter on your service entrance.
Half the amps on each of the two phases...equals twice the amps on a single side.
You save nothing.

Evil kwh meter,evil very satanic.