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even small voltages can kill as they can throw your heart out of sink, 240 even in small bursts will kill some people
One of my colleagues knows someone who is partly paralysed down one side. His dad had the cover off the washing machine to work on it when he was a kid. He picked up a screwdriver and poked it into the machine when his dad left the room to get another tool and received a shock.
240v killed my mate Chris 🙁
He'd fixed his girlfriend's washing machine, plugged it in to check, all good, realised he'd left screwdriver in the machine reached in to get it. 🙁
WorldClassAccident - MemberUncleFred - What are the chances of that link being worksafe?
Perfectly safe for work, if you work in a "Private Shop"
Mmm, so 240v [i]can[/i] kill you... Is there any way of [i]guaranteeing[/i] it will kill you?
50mA will kill you. 30mA might well do so.
As others have said - its all down to the current (amps). Dry skin is an alright (I use the term loosely) insulator - plenty of resistance, so not much current flow (assuming you're acting as an earth path). You'll probably get away with it. Probably.
Wet or sweaty skin (nerves from working on live electrics maybe?) has a low resistance, so you get a lot of current flow. Bang, you're dead.
If you manage to connect yourself in series with another electric load that's drawing current - you're definitely dead.
A fuse or an MCB protects against overcurrent. If you have a 13A fuse in your plug, by the time it blows, you'll probably be dead (remember 50mA = 0.05A). An RCD measures the difference in current in the live and neutral cores. If they differ by more than the "trip" value, they trip.
I've had a few shocks in my time (I work as a lighting technician). I've had yet more near misses. I could happily live the rest of my life without any more of either
anyway, your very unlikely to come across a 240v supply in the UK, seeing as mains is 230. oh the joys of learning this stuff presently.
UK mains may now be 'officially' 230v, but due to the tolerance band, you'll still see 240v and more at the socket. I'm currently retraining to be a spark so keep up the bodging chaps. Incompetent DIY'ers should keep me in work for years if they can manage to stay alive long enough. 
The flicky switches in your consumer unit are likely to be MCBs, not RCDs, so are designed to protect the wiring installation, not you. RCD protection is a relatively recent thing and many consumer units won't have any fitted. If you have RCD protection (either RCCB or RCBO devices - should say on the front) and they aren't tripping when you give yourself a pisser then you have a problem.
I really dont understand why people WHO HAVE NO IDEA ABOUT ELECTRICITY seem to think that it is ok to work with it. Its a seriously dangerous force. It isnt just your life you are putting at risk, but family and anyone who comes to your house. Why do you think that the electrical instalaton industry is so tightly regulated? I didnt do a 4 year apprenticeship for nothing.
230v can and often does kill. It can also cause fires and explosions. Its not worth the risk and i would say you have been lucky so far.
As said above 240V can and does kill, fact.
I have been told from a reliable source that 60V DC has the capacity to kill as well. Sparky pal of mine told me once that a 13A fuse by the time it blows could be passing 2 or 3 or 4 times that current, and you are fried by the time it does.
I also heard on a static electricity course that 1 joule of electricty in the wrong place on your heart can stop it, that is 1W for 1sec, which is a very small amount of electricity. Static from clothes for example is 1000's of V but very low current so its harmless. Static discharge from a large helicopter grounding however can kill you.
So dont be silly and get a sparky in 🙂
a 13A fuse by the time it blows could be passing 2 or 3 or 4 times that current, and you are fried by the time it does.
Your sparky friend is talking a mild amount of bollocks. You'd be fried without the fuse necessarily blowing at all. 50mA will kill you. That's 0.05A. 0.05A won't blow a 13A fuse.
Dudie - you are right that fuse may not blow, but he is not talking bollocks as you put it, a fuse will pass current a number of times higher than its nominal rating before it blows.
Quite correct. Not disputing that. The insinuation was that you would be fried because of the fuse not blowing at 13A. All I am saying is that you would be fried regardless - you would be dead long before the current got anywhere near level required to blow the fuse. Must dash, got to swot up on me live testing homework!
's fair enuf....
I saw a guy die at a gig. He was a guitarist and as they were tuning up he grabbed the mike stand, did a little shaky dance and fell over, dead.
Turns out he had got fed up with the fuse in the amp blowing so decided to use a paper clip instead.
ive seen peuple use cut down, then soldered on nails as 'fuses' on a lighting circuit 😯
cullen-bay - Member
anyway, your very unlikely to come across a 240v supply in the UK, seeing as mains is 230. oh the joys of learning this stuff presently.
I like that one.
Sorry to do this but when the statutory mains voltage at LV single phase changed from 240V +/-6% to 230V +10%/-6%, what do you think the electricity companies did? Go out and change the voltage at every substation (easier at the primaries but still a git)? Or work out that 240v +6% and 230V +10% are virtually identical and leave well alone? Could it even be that this is why the tolerance band chosen is the one it is? You got it.
And by the way we design to be as close to the upper limit as possible at no load, so that as the load comes on and the voltage drops we have as much room to play with as possible. Saves on copper / aluminium and means you the great British public pay slightly less distribution charges on your electricity bills.
WCA...that downstairs light, try the same trick again but touching an earthed bit of plumbing...you'll get a much bigger bang! This is why its no longer normal practise to earth the kitchen sink as its quite likely you will drop a kettle or electric whisk into the water...the shock will be less severe if the sink is unearthed. Also why plumbing and elecrics are earthed together in bathrooms, so everything is at the same potential. A big plus point for push fit plastic plumbing 🙂
Yeah, yeah, yeah, all very interesting stuff: real men talking about really manly 'lectric and all that but no one's actually told me how to guarantee death using the 230/240/250/whatever volts that my house has got.
Does dropping a toaster into a bath really work [b]one hundred percent[/b] of the time???
Cut the skin on one thigh and the opposite shoulder. Apply phase to one and neutral to the other, both into the cuts.
Please do not do this.
No no no, that sounds painful! I'm looking for a quick 'n' easy way out that can be done at home with minimal preparation. Does electrocution involve lots of pain and thrashing about? Or is it pretty instant?
Thanks for your input though! 🙂
I zapped myself with the mains once whilst working live. I struggled to pull my hand off the wire and the flow went right through my chest ,weird feeling when it hits your heart .
My arm took days to go back to normal what with all the tingling
I've known people killed not just by the 240vac, but the stuff they've fallen on to. Ffs people, be careful.
yeah, i was working at a site, and another electrician (honest) f'ed up. result was a coms engineer grabbed hold of a piece of metal conduit at 230v, 32 amps (yes the amps are the really dangerous part). He was on load of metal racking. Result was he was thrown about 12 foot onto the concrete below. Luckily he was just bruised and shaken. His mate started on me, thought he was going to go for me but some other people calmed him down. Lets just sy it was not a good experience for anyone. Does no one remember that incident with the mp's daughter who died frm a shock in the kitchen. That was more or less what sparked off this whole 17th edition thing i think.
People say amps kill because of the I squared R losses as the current goes through your body, but there are other ways to die.
If your lucky a few milliamps (50 has been quoted on here and I'm not going to argue with that) interfere with your nervous system - heart attack - dead. That's really the voltage signal, which maps onto your natural electrical system fairly well, killing you.
Next up the shock causes trips and falls - and the fall kills you.
A weird classic is the man who jumps on to an overhead line and grabs one of the conductors - but he isn't making a circuit, possibly even the instantaneous protection that they have on that kind of circuit kills the volts, so he just hangs there until his strength gives out and he falls with predictable consequences. Possibly apocryphal that one.
Getting into the nasty ones, the current cooks your flesh - ever seen a bit of meat that's been in the microwave too long? - and you die.
Worse maybe you survive initially but the shock from the burns kills you within a day or two.
But that's better than the cooked flesh slowly going off inside you with the accompanying blood poisoning.
Of course that doesn't consider the various problems caused by electrical flash or fire.
If there are any doctors out there they may wish to correct me on the details.
For everyone else I think it may be time to close this thread.
Don't play with it if you don't know what you're doing - and if you do know what you're doing, play carefully.
240v killed my mate ChrisHe'd fixed his girlfriend's washing machine, plugged it in to check, all good, realised he'd left screwdriver in the machine reached in to get it.
Wasn't down Sussex/Kent way recently was it? There was this exact tale in our local paper not so long ago - someone killed whilst repairing a washing machine.
Any changing of plug sockets / light switches / light roses etc in the house I make sure the power is off at the mains. Not worth the risk IMO...
Someone said "Volts jolt, amps kill". This is very confusing and can give out the wrong message that any voltage is safe if the amps are low. The fact is, it only takes a tiny amperage to kill you. The reason we don't all die when we touch a battery is because it takes a lot of volts to pass though your heart.
Unfortunately, what they teach in schools up to secondary level is wrong. They can't seem to explain the difference between volts and amps and this was one of the first things our lecturer at college put is straight on. Years later, I had an argument and lost a friend over this one evening. She was being paid to mark science exam papers, incorrectly! No wonder people get confused, hate Physics and that this country has so few people wanting to be engineers!
I'll explain why high voltage kills, not high amps: Put simply, you need high voltage to "jump" through you. The higher the voltage the easier this becomes. A deadly shock attacks the heart and the most effective way is to allow current to pass through your rib cage. To minimise this, people having to work on live high voltage equipment will often stand on rubber mats/wear rubber boots (to prevent a route to earth through their feet) and always have one hand only on the equipment.
Alternating current (AC) is used for transmission of power as it looses less energy than DC. In order to efficiently transmit power over distance, we use AC high voltage and low current. That's why power lines suspended across the countryside are at very high voltages. If we used DC and low voltages, the lines would need to be incredibly thick to handle the current, but we'd still loose a lot of power. e.g, double the voltage, halve the current. If you've ever installed a powerful car ausio system, you will have found that the power cable on offer is very thick. It needs to be to handle the current demand of a system powered by just 12-16v.
Back to living creatures... It only takes a few millamps to kill you (I believe the figure to be 1.6 Milliamps or 0.0016 amps ) - it will cause your heart rhythm to be interrupted and if you don't survive, it will be because you've had an heart attack.
Conversely, holding the terminals of a low voltage, high current source, such as a 50Ah car battery, will not even register the slightest tingle and is completely safe.
I can't remember exactly what a safe voltage is, but it's something like 50v, or maybe a bit less. 50v [i]will[/i] give you a nip and it really does depend on moisture (a conductant). Sweat is a good conductor, perhaps due to the salt content. If your skin is bone dry, you are less likely to get a circuit through you.
Conductivity is a big factor in whether you get a shock or not and how bad the shock is. If you are soaking wet, expect a big one. If your dry, you might not even get a shock.
However, if you introduce high voltage and high current over a period of time, you will fry - nasty.
Just don't fxxk with high voltages. Turn the juice OFF, but if this is not posible, proceed with extreme caution (like when diagnosing electonic equipment faults). Better still, get a man who is qualified to deal with it.
I like the quote somebody else made
I think it effectively just rebooted my head lol.
Alternating current (AC) is used for transmission of power as it looses less energy than DC.
AC is easier to convert to high voltage and back than DC - just use a couple of copper coils around a steel core, or transformer to the rest of us.
Also building AC circuit breakers is a sight simpler as you have some zero crossing point where arc extinction is easier.
It is the high voltage and low current that is more efficient as the I squared R losses are lower for any given power, not whether it's AC or DC.
However the next generation of power transmission (and indeed some that already exists - cross channel link anyone) will probably be DC for a number of reasons including ease of insulation and the decoupling of AC systems which can improve stability in large networks - not a problem in the UK as were too small, but in the States or if they ever build the Afro-European supergrid they're talking about.
But that probably won't run at 240V.
I'll explain why high voltage kills, not high amps
We run perfectly safe electric fences round some of our substations - 50,000V I seem to remember (Power fence are one manufacturer - google 'em). But limited to 5 joules (so not enough power to cook you) and not 50Hz so it doesn't mess your nervous system up.
So it's not as simple as Amps kill or Volts kill - it's a combination (they are intrinsically related after all), but frequency also comes into it and it depends on how you want to die. Please don't though.
The rest of what you said I'd not disagree with (except that 240 V is referred to in the industry as Low Voltage).