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Thread ID: 83272	2007-09-26 00:57:00	Electric shocks	FoxyMX (5)	PC World Chat

Post ID	Timestamp	Content	User
595091	2007-09-28 08:31:00	A toaster element would snap (so it kills the current), if you put something metallic in it . Not so Speedy, so don't try it . You can be killed by even indirect contact with a live conductor, i . e . touching with something wet enough to conduct a lethal current . I've only had two 230 volt shocks in a long electrical career but that was two too many . One of the lesser known risks is a disturbed heart rhythm . You feel a bit crook so you go home and lie down, then cardiac arrhythmia sets in and you never wake up . That nearly happened to me after a live object literally dropped into my hand, I was OK for a while then started to feel crook so I headed for home, then felt worse as i drove so I stopped at a Doctors' surgery where I was kept until medication dealt with the problem . Never take chances with electricity, and don't give or take uninformed advice about the risks . Pardon the pun, but that can be fatal . Cheers Billy 8-{) :stare:	Billy T (70)
595092	2007-09-28 10:00:00	I feel that I should add something here... but maybe not.:waughh:	Shortcircuit (1666)
595093	2007-09-28 11:31:00	Let me see if my Electricians memory is correct . The supply onto the house is two wire . Phase & Neutral . This goes to the meter box then into your fuse board . The Phase/Live goes thro the main switch . From the dead side of this it is looped to one side of all the fuses/circuit breakers . Then out to lights & power points, etc . The Neutral goes to a brass bar . All the neutrals run back to here . There is also an almost identical Earth bar . All the earth wires run back to here . Also from the Same stud as the Main Neutral, an earth wire runs to a 2 metre Earth Rod outside . All copper water pipes had to be connected back to the earth bar, hot & cold pipes bonded together . same for any 'Iron' waste pipes . I also earthed cast iron baths, Shower stainless trays & stainless sink benches . Even tho I did not have to if the waste pipe was plastic . The Earth & neutral bars are about the same length . There is one stud on each, opposite each other, on purpose . Across these is a brass link which physically bonds the Earth & Neutral bars together . So there should not be a difference in potential between them . The test I did on a power point, for instance, with a voltmeter was :- Phase to earth, 230 v . . Phase to Neutral . . 230v . . Earth to Neutral . . Zero . In effect your neutral is your Earth & Your earth is your neutral . All the houses in your street have an earth spike connected to the house Neutral, so you all share the earth network . At the transformer that supplies your street . The supply in will be 3 Phase, Delta connected, high voltage, probably 11,000 volt . On the output side it will be Star connected . But now 230 v per phase . The Neutral is taken from the Star Point of the output windings . The Earth mat around the transformer is also connected to this same Neutral point . If you were to have a fault at home, the fuse would blow due to the high fault current drawn . I was taught that the resistance thro' the ground was less than the resistance of the copper neutral wire . But that it still took a hefty amount of current to flow to blow that fuse . That is why an RTD on your fuseboard is preferable, it only takes a few miliamps for the RTD to sense & disconnect the power . I am sure most people have taken out a blown porcelain fuse to replace the fuse wire . And seen the copper wire splash on the inside?? It takes a bit of power to do that . In the UK I think they still have 240v two wire into the house with a smaller earth spike or the earth connected to the incoming iron water pipe . The water board workers didn't like this idea, they were getting shocks from the pipework . I also believe that RTDs are mandatory on all new jobs (not really sure tho) . Also in the UK their earth pin is at the top . In NZ it is at the bottom . Why? When a three pin plug starts to fall out, it is usually the top pin that lets go first . The UK way means that the Earth pin disconnects possibly leaving the Earth & Neutral connected . Our way means that the Phase & Neutral disconnect first & the earth pin last . In my opinion our Multiple Earthed Neutral System I sthe best way . Here endeth the lesson . PS I am sure someone is going to disagree with me !!!!!! PJ	Poppa John (284)
595094	2007-09-28 11:35:00	Let me see if my Electricians memory is correct . The supply onto the house is two wire . Phase & Neutral . This goes to the meter box then into your fuse board . The Phase/Live goes thro the main switch . From the dead side of this it is looped to one side of all the fuses/circuit breakers . Then out to lights & power points, etc . The Neutral goes to a brass bar . All the neutrals run back to here . There is also an almost identical Earth bar . All the earth wires run back to here . Also from the Same stud as the Main Neutral, an earth wire runs to a 2 metre Earth Rod outside . All copper water pipes had to be connected back to the earth bar, hot & cold pipes bonded together . same for any 'Iron' waste pipes . I also earthed cast iron baths, Shower stainless trays & stainless sink benches . Even tho I did not have to if the waste pipe was plastic . The Earth & neutral bars are about the same length . There is one stud on each, opposite each other, on purpose . Across these is a brass link which physically bonds the Earth & Neutral bars together . So there should not be a difference in potential between them . The test I did on a power point, for instance, with a voltmeter was :- Phase to earth, 230 v . . Phase to Neutral . . 230v . . Earth to Neutral . . Zero . In effect your neutral is Your Earth & Your Earth is your neutral . All the houses in your street have an earth spike connected to the house Neutral, so you all share the earth network . At the transformer that supplies your street . The supply in will be 3 Phase, Delta connected, high voltage, probably 11,000 volt . On the output side it will be Star connected . But now 230 v per phase . The Neutral is taken from the Star Point of the output windings . The Earth mat around the transformer is also connected to this same Neutral point . If you were to have a fault at home, the fuse would blow due to the high fault current drawn . I was taught that the resistance thro' the ground was less than the resistance of the copper neutral wire . But that it still took a hefty amount of current to flow to blow that fuse . That is why an RTD on your fuseboard is preferable, it only takes a few miliamps for the RTD to sense & disconnect the power . I am sure most people have taken out a blown porcelain fuse to replace the fuse wire . And seen the copper wire splash on the inside?? It takes a bit of power to do that . In the UK I think they still have 240v two wire into the house with a smaller earth spike or the earth connected to the incoming iron water pipe . The water board workers didn't like this idea, they were getting shocks from the pipework . I also believe that RTDs are mandatory on all new jobs (not really sure tho) . Also in the UK their earth pin is at the top . In NZ it is at the bottom . Why? When a three pin plug starts to fall out, it is usually the top pin that lets go first . The UK way means that the Earth pin disconnects possibly leaving the Earth & Neutral connected . Our way means that the Phase & Neutral disconnect first & the Earth pin last . In my opinion our Multiple Earthed Neutral System Is the best way . Here endeth the lesson . PS I am sure someone is going to disagree with me !!!!!! PJ	Poppa John (284)
595095	2007-09-29 00:39:00	Funny about that Earth/ground pin on top or bottom thing. I never had any reason other than convention to put the ground pin on the bottom, but I occasionally see them on the top..although I have never seen any code requirements on either position. The UCC (Universal Contractors' Code) requirements might have a preference, but I don't remember it. We just did it that way for- what seems -ever. I personally see a good value to the pin on top, as it might also physically protect the hot blade from getting a hairpin or metallic toy or so across the hot and common at the same time making it a little safer. Our ground/earth lug is longer than the others by a noticeable amount, so it might be safer than the ones you mentioned. Typically, most newer homes require Hospital Code outlets (the wall side) to have five lbs of "hold" onto any one pin, so the combined pull to remove a plug would be fifteen lbs...quite substantial. Not all homes are up to that code, and it's not uncommon to find loose recepticals and plugs that fall out easily. I once had to change out over 11,000 recepticals to get a hospital up to accreditation code for a big federal inspection. I hired six other guys and we spent weeks doing it. We got to sell the old units at a swap meet and made a killing. We had to work them "hot" as they could not afford to shut down any circuits for patient considerations. Thankfully, we had 120 volts to deal with as we got buzzed quite a few times each day.	SurferJoe46 (51)
595096	2007-09-29 02:02:00	joe...The earth pin IS longer than the other two both here & the UK PJ	Poppa John (284)
595097	2007-09-29 02:18:00	joe...The earth pin IS longer than the other two both here & the UK PJ Modern plugs also have the top half of the phase + neutral pins coated in plastic, to prevent something like a knife slipping in between the plug and the socket from shorting across phase + neutral.	somebody (208)
595098	2007-10-01 00:41:00	Having lived in the UK, America & NZ I have experienced all the different types of electrical fittings etc. I like the UK one (well the ring main at least) because all the plugs had their own fuse in them. Good idea - but it does make the plug a bit clumsy for travel. Also the Brits had been through about 5different standards over the years - life got extremely interesting if you changed houses and found all plugs etc had to be changed. One house we lived in for a while seemed to have all the different standards included. Using a vacuum cleaner was quite a challenge! We had more adapters than soft Mick. America we found convenient and having the dual voltage an advantage. You could even get plugs whereby you just inserted the wire for the appliance then closed the plug. It automatically made the connections inside - it worked too. Funny I never got a shock from the 120v supply so I don't know if it was considerably less than the ones I have had from 230v etc. A lesson I soon learned in America was that the average person was very electrical and mechanically literate. I know we claim that here in NZ but many of the things highly illegal here were common to the yank. The first week there (in 1967 I should add) I noticed a machine in our local store for testing radio valves - now who would want or be able to use those? But then I saw little old ladies popping their handbags open - getting a load of valves out and testing them all. I just cannot imagine that in NZ. The NZ electrical system seems to be simple, safe, boring, and reliable. Not a bad result. Pity the electricity is so expensive now. Tom	Thomas01 (317)
595099	2007-10-01 07:43:00	Very Strange. Some of you that have been electrocuted are still posting. Does this mean there is life after death?	gradebdan (2186)
595100	2007-10-01 08:08:00	Very Strange . Some of you that have been electrocuted are still posting . Does this mean there is life after death? The problem is semantic, not electrical . Some people just don't understand or cannot use correct english . Electrocution means "to kill in any way by electricity" . The writers on this forum are presumably still alive, from the neck down anyway, so by definition they have never been electrocuted . What they may have experienced is an electric shock, something that just about every person on this planet will experience at one time or another from static electricity if nothing else . A small number have been careless and have experienced a shock derived from the electrical supply . That shock may or may not have been the full 230 volts, but what is for sure is that it was at a very low current level . Hence they live to write about it from a position of blissful ignorance as to just how close they strayed to electrocution . If they maintain that blissful state, next time it might just get them . Cheers Billy 8-{) :groan:	Billy T (70)
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