Why has DIYNOT got a electrics forum?

[Big_Spark]

The idea that you could change the Freq of the supply in the UK is about as practical as changing the side of the road we drive on...

A bad comparison. Sweden used to drive on the left.

Bullshiite..he may get away with it once or twice, but if he went across all three phases he would certainly be killed, probably instantly as his heart would be fed three different frequency supplies 120 degrees out of phase, it would stop his heart DEAD...

Exactly. Bullshite.

The frequency of the phases is the same for each phase.

If it was a 240V 3-phase supply, the phase-phase voltage is 415V. THAT is what kills, it does it by almost instant cooking. The phase angle is irrelevant. Please describe how he could get across 3 phases at once.

Big -spark, slippyr4 has brought up several inaccuracies in your assertions. For heavens sake read through your posts before you submit them.

Oilman, you are correct that the PD across phases is 415V, but your forgetting that you would also be in contact with the general mass of earth, unless levitating, as a result you would be susceptible to the fact that each phase IS 120 degrees out of phase with respect to each other (240V phase-Earth or Neutral) and in this situation it is the effect of the frequency oscillations on the heart, so I am led to understand, that does the damage.

Of course 415V coursing through your body is not going to be a pleasant experience, but the effect of three or even two serices that are both at 50Hz and 120 degrees out of phase will not be good for the heart.

 

[Big_Spark]

Is this the electricians version of who can p*&s the furthest

No - sadly it's another example of Big_Spark coming on here and spouting complete b*llsh*t, trying to back it up with a number of big "I am" statements, and then melting away when pressed to prove it.

A situation which I'm sure is all too familiar.

BAS..your the fecker spouting Bull. All you ever do is attack abd insult people as others have poiinted out. you are the biggest annoyance on these forums, just as you were over the other side, before you were proved to be a liar and you stamped your feet and left with your dummy..

Grow up man.

 

[Big_Spark]

BAS..the point I was making is that there is a significant difference between a shock from Phase to earth, where the current flowing in your body will be determined by your body's resistance, as for any electrical circuit, BUT if you complete a circuit by making the connection ACROSS A BROKEN NEUTRAL, then the shock you recieve will be the current flowing in the circuit at that time..you will effectively become part of the circuit rather than a seperate circuit..(as with a Phase to neutral or Phase to earth shock)

No you won't. No you can't. It is simply impossible for that current to flow through you, a fact which was initially recognised by Georg Ohm.

And anyway - if the neutral had been broken, and therefore the circuit interrupted, the current flowing "at the time" would have been zero, so even if your theory wasn't rubbish it would be rubbish.

If you become part of the circuit then you are an impedance of a few hundred to a few thousand ohms in series with the overall load on the circuit.

So if the load had been 5 ohms, and the current therefore would have been 46A, if you put, for argument's sake, 500 ohms of you across the break in the neutral, the load on the circuit is now 505 ohms, and therefore the current that will flow will be 455mA.

For your theory that 46A would flow, the potential difference across the break in the neutral would have to have risen to 23kV. How is it going to do that?

You seem to be recycling ignorant old wive's tales without any thought to the physics behind them.

BAS, it is obvious to all that if the neutral was broken then there would be no current flowing at that time, I didn't thatink that needed stating..however if the circuit is energised, connecting the neutral would allow the full load being drawn to flow..do you agree with that or do you know something about physics man has yet to discover?

That being the case..IF YOU connected the neutral across your body then you have completed an electrical circuit, the circuit would energise as if you were not forming the bridge (assuming the neutral was intact) and at that time the load of the circuit would flow through you, just as if you were a piece of wire in the circuit..albeit with a lot higher resistance than wire...

I appreciate that this situation is one most people never find themselves in, 95% of electric shocks are phase to earth and in that situation, as everyone agrees, the current flowing would be determined by the resistance of your own body and the potential difference flowing across it, this is the same for Phase to neutral shocks.

In neither situation do you become part of the electrical circuit, you ARE the electrical circuit, but if you bridge the neutral via your body, and the circuit is energised, at the moment of energisation, the full potential current of the circuit will flow across you, although the bodies resistance will have an effect on this as you will simply become a high impedance load on the circuit yourself..............................
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I'm beginning to think I have thought about this wrong, I cannot say i have ever given this a great deal of consideration, but the more I think of this, the less sure I am of what I believed..my last comment has just put a seed of doubt...later i will do a circuit diagram and do a proper calculation...I think the lack of thinking about it has allowed a misnomer to sit in my head for year that I failed to recognise a flaw in..and stubboness has likely prevented me from seeeing that flaw....

One thing I do know, as any spark will tell you, a shock across the neutral is 100% more painfull that phase to earth or phase to neutral...this could be phsychological though and simply enforced what i failed to think about...

I'll post later with a circuit diagram, regardless of the outcome....

 

[oilman]

........................

Oilman, you are correct that the PD across phases is 415V, but your forgetting that you would also be in contact with the general mass of earth, unless levitating, as a result you would be susceptible to the fact that each phase IS 120 degrees out of phase with respect to each other (240V phase-Earth or Neutral) and in this situation it is the effect of the frequency oscillations on the heart, so I am led to understand, that does the damage.

Of course 415V coursing through your body is not going to be a pleasant experience, but the effect of three or even two serices that are both at 50Hz and 120 degrees out of phase will not be good for the heart.

You cannot go around making statements like this and expect to get away with it. Unless you stand on damp earth, in bare feet, you will probably be in reasonably well insulating shoes or boots, and on a floor which will be a poor conductor. In that case the connection to earth will be capacative, and the impedance will mean the phases will be something other than 120 degrees, AND the current and voltage will not be in-phase.

415V does not course anywhere, it is merely the pressure which causes the coulombs to move.

 

[slippyr4]

That being the case..IF YOU connected the neutral across your body then you have completed an electrical circuit, the circuit would energise as if you were not forming the bridge (assuming the neutral was intact) and at that time the load of the circuit would flow through you, just as if you were a piece of wire in the circuit..albeit with a lot higher resistance than wire...

correct

I appreciate that this situation is one most people never find themselves in, 95% of electric shocks are phase to earth and in that situation, as everyone agrees, the current flowing would be determined by the resistance of your own body and the potential difference flowing across it, this is the same for Phase to neutral shocks.

correct

In neither situation do you become part of the electrical circuit, you ARE the electrical circuit, but if you bridge the neutral via your body, and the circuit is energised, at the moment of energisation, the full potential current of the circuit will flow across you, although the bodies resistance will have an effect on this as you will simply become a high impedance load on the circuit yourself..............................

Still a worrying lack of understanding.

 

[ban-all-sheds]

BAS..your the fecker spouting Bull.

So what have I said here that's bs?

All you ever do is attack abd insult people as others have poiinted out.

Do I? Even allowing for the normal generalisation that everybody makes when they say "all you ever do", you must think that a high number of my 7825 posts so far are attacking and insulting. How many do you think you can find?

Are you perhaps remembering just the ones where I've disagreed with you, or pointed out that you are wrong?

And what others have also said the same?

you are the biggest annoyance on these forums,

It seems to me that you find anybody who disagrees with you annoying, particularly if they persist in ignoring your blustering.

just as you were over the other side, before you were proved to be a liar and you stamped your feet and left with your dummy..

I'm sorry - I have absolutely no idea what you're on about. "The other side"???

Grow up man.

It's interesting that you now seem to be coming round to the idea that what I and slippyr4 have been consistently and calmly pointing out is right, and that you have been wrong. But until that realisation dawned you had to go through your usual insulting and "don't argue with me I know far more than you" kind of stuff.

Are you sure that it's I who needs to grow up?

 

[pickles]

Chill out guys. Your taking this just a bit tooo seriously now

Heres a compromise statement that you can all agree on

"Electricity can be dangerous"

 

[Nige F]

So how did the CHAIR work AC or DC and what volts.....been wondering some since I saw the Green Mile

 

[slippyr4]

http://en.wikipedia.org/wiki/Electric_chair

 

[ban-all-sheds]

So how did the CHAIR work AC or DC

Err - not been paying attention? //www.diynot.com/forums/viewtopic.php?p=247760#247760

and what volts.....

Different voltages & durations have been tried. Plenty of info here.

 

[empip]

................. was not right for a couple of weeks...

Certain about that ?

 

[ban-all-sheds]

ps are you sure about your numbers, hse reckon it was 67 fatals and 4000 injuries from falls in 2003 (still far too many)

The figures are from RoSPA/DTI, and they are figures for the home (or possibly home and leisure).

Any HSE figures you have will be for the workplace, and so should be added to home/leisure to get an idea of the total for the whole country...

The figures for 2002 were about 35,000 for the home, and 2,000 for leisure - and that's just injuries, not deaths.

 

[Big_Spark]

Still a worrying lack of understanding.

No slippery it is not, I had a think about this and have realised why I am correct..I'll do a post about it later but I have only just got in after a nearly 2.5hr journey home due to some numpty crash testing their car on the A12...Tis silly season on the roads again...Oh Joy..

Anyway..the reason you will recieve a shock greater than the resistance of the body is due to resistance in series. If your in parallel with the supply, as you and I have agreed on, it is your body resistance that counts, but if your in series with the circuit, and your not grounded out elswhere, then you will be a resistor of 1500 Ohms in series with the supply...and this will be added to the resitance of the rest of that circuit, so you will recieve a shock at the full load of that circuit....which will be the resistance of the circuit added to the resistance of the body...

Work it out and see what you get...let me have a cuppa and my dinner and I will do a longer post on this...Oh, and to make sure I was thinking it correctly, as it is a long time since giving this much thought, I asked about 8 Guys at work today, and one of them is a Consultant Engineer with a Masters in EE and is MIEE, CIBSE and CEng...they all said the same..

 

[slippyr4]

Work it out and see what you get...let me have a cuppa and my dinner and I will do a longer post on this...Oh, and to make sure I was thinking it correctly, as it is a long time since giving this much thought, I asked about 8 Guys at work today, and one of them is a Consultant Engineer with a Masters in EE and is MIEE, CIBSE and CEng...they all said the same..

I already did work it out, in my 9:32pm post yesterday.

I await your proof that ohm's law is incorrect. You know, if you're right you should patent it. You could make a mint.

 

[Big_Spark]

Work it out and see what you get...let me have a cuppa and my dinner and I will do a longer post on this...Oh, and to make sure I was thinking it correctly, as it is a long time since giving this much thought, I asked about 8 Guys at work today, and one of them is a Consultant Engineer with a Masters in EE and is MIEE, CIBSE and CEng...they all said the same..

I already did work it out, in my 9:32pm post yesterday.

I await your proof that ohm's law is incorrect. You know, if you're right you should patent it. You could make a mint.

FFS...work out resistance in series...quicky example for you..

Motor winding has a resistanbce of 30 Ohms

Human Body has a resistance of say 1500 Ohms..

Now you complete the circuit when it is energised but connecting the Phase to Phase or the Neutral to Neutral..so...

1500 + 30 = 1530 Ohms

So the total resistance of the circuit is 1530 Ohms

Now the current5 that will flow in the circuit will be

240/1530 = 0.165A...THIS IS THE FULL LOAD CURRENT OF THE CIRCUIT

Now if you do not understand this, you do not understand electricity...

BTW..I never said Ohms law was incorrect, you did as you failed to read my posts correctly and understand what I said...