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Earthing a kitchen sink - what size cable?
I'm about to install the (stainless steel) sink in my new kitchen, and
of course the spec sheet that came with the sink mentions the need to earth it. However, I can't find any guideline as to what gauge of earth wire I should use: can anyone give me an idea? As a starting-point: I have a lot of gash 1.5mm2 lighting cable: would the earth conductor from that (suitably sheathed of course) be sufficient? Many thanks. Bert http://www.bertcoules.co.uk |
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Bert Coules wrote:
I'm about to install the (stainless steel) sink in my new kitchen, and of course the spec sheet that came with the sink mentions the need to earth it. However, I can't find any guideline as to what gauge of earth wire I should use: can anyone give me an idea? As a starting-point: I have a lot of gash 1.5mm2 lighting cable: would the earth conductor from that (suitably sheathed of course) be sufficient? 16mm2, and it must be earthed withn 2m of the sink, so you may have to take a tile up to get an earth rod in as well. NT |
#3
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NT,
16mm2... OK, thanks for that. ...and it must be earthed within 2m of the sink, so you may have to take a tile up to get an earth rod in as well. There's no earth anywhere near two metres of the sink in any direction including straight down. Does the sink have to have a *direct* independent connection to actual earth? The rest of the internal copper pipework is earthed back to the consumer unit (in very hefty cable, which I take to be 16mm2) and thence to the incoming supply's earth; surely it would be sufficient to bond the sink to the nearest available copper pipe? Bert http://www.bertcoules.co.uk |
#4
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"Bert Coules" wrote in message ... NT, 16mm2... OK, thanks for that. ...and it must be earthed within 2m of the sink, so you may have to take a tile up to get an earth rod in as well. There's no earth anywhere near two metres of the sink in any direction including straight down. Does the sink have to have a *direct* independent connection to actual earth? The rest of the internal copper pipework is earthed back to the consumer unit (in very hefty cable, which I take to be 16mm2) and thence to the incoming supply's earth; surely it would be sufficient to bond the sink to the nearest available copper pipe? Bert Aren't the pipes bonded? Or are they plastic? If the pipework is copper, then they should already have earth straps and green/yellow wire to them. If they have been bonded, then connect the sink to one of the straps. |
#5
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"Bert Coules" wrote in message ... NT, 16mm2... OK, thanks for that. ...and it must be earthed within 2m of the sink, so you may have to take a tile up to get an earth rod in as well. There's no earth anywhere near two metres of the sink in any direction including straight down. Does the sink have to have a *direct* independent connection to actual earth? The rest of the internal copper pipework is earthed back to the consumer unit (in very hefty cable, which I take to be 16mm2) and thence to the incoming supply's earth; surely it would be sufficient to bond the sink to the nearest available copper pipe? Bert http://www.bertcoules.co.uk Yes, 4mm2 between sink and hot/cold pipes. I usualy also go to nearest socket too to be 100%. But in no way is 16mm2 needed to your sink! |
#6
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"BigWallop" wrote in message . uk... "Bert Coules" wrote in message ... NT, 16mm2... OK, thanks for that. ...and it must be earthed within 2m of the sink, so you may have to take a tile up to get an earth rod in as well. There's no earth anywhere near two metres of the sink in any direction including straight down. Does the sink have to have a *direct* independent connection to actual earth? The rest of the internal copper pipework is earthed back to the consumer unit (in very hefty cable, which I take to be 16mm2) and thence to the incoming supply's earth; surely it would be sufficient to bond the sink to the nearest available copper pipe? Bert Aren't the pipes bonded? Or are they plastic? If the pipework is copper, then they should already have earth straps and green/yellow wire to them. If they have been bonded, then connect the sink to one of the straps. Should have added that you use the same gauge cable that is already on the earth straps. :-) |
#7
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"Bert Coules" wrote in message ... I'm about to install the (stainless steel) sink in my new kitchen, and of course the spec sheet that came with the sink mentions the need to earth it. I'm probably being extremely ignorant/innocent here but why do you need to earth a sink? Is it to use with the electric hammer? Mary |
#8
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BigWallop,
Thanks for the reply. Aren't the pipes bonded? Or are they plastic? No, the internal pipework is all copper and it is bonded, but not under the kitchen sink. The connection is in the bathroom. Bert http://www.bertcoules.co.uk |
#9
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Tim,
Yes, 4mm2 between sink and hot/cold pipes. Thanks, Tim. Is that a cable from the sink to, say, the cold pipe and a jumper cable connecting the cold pipework to the hot? But in no way is 16mm2 needed to your sink! It did seem a tad large, I admit. Bert http://www.bertcoules.co.uk |
#10
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Mary,
I'm probably being extremely ignorant/innocent here but why do you need to earth a sink? I agree that on the face of it it seems an odd requirement, but it just seems simpler not to argue, really. I would be interested in an idiot's-guide explanation as to why it's necessary, if anyone would be kind enough... Bert http://www.bertcoules.co.uk Presumably the theory is that it's possible inadvertently to touch something live with one hand and the sink with another, so Is it to use with the electric hammer? Mary |
#11
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"Bert Coules" wrote in message ... Tim, Yes, 4mm2 between sink and hot/cold pipes. Thanks, Tim. Is that a cable from the sink to, say, the cold pipe and a jumper cable connecting the cold pipework to the hot? Yes, I never cut my cables. used to strip off insulation and then fit to earth clamp by removing the screw completely to put wire under efore tightening up again.(if that makes sense!) But in no way is 16mm2 needed to your sink! It did seem a tad large, I admit. Bert http://www.bertcoules.co.uk |
#12
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Tim,
Thanks for the reply. I never cut my cables. used to strip off insulation and then fit to earth clamp by removing the screw completely to put wire under before tightening up again.(if that makes sense!) It does, except for the bit about never cutting your cables. You must cut them to length, surely? Bert http://www.bertcoules.co.uk |
#13
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#14
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Bert Coules wrote:
I agree that on the face of it it seems an odd requirement, but it just seems simpler not to argue, really. I would be interested in an idiot's-guide explanation as to why it's necessary, if anyone would be kind enough... We've been through this multiple times - as a groups.google.com look in uk.d-i-y will show. No-one's yet been arrassed to put the Conclusion in the FAQ. There is NO requirement to earth a kitchen sink. The IEE On-Site guide goes so far as to use almost exactly those words - i.e. it doesn't just not mention sinks under 'things wot must be earthed'; after that list, it gives another list of 'things wot you might think must be earthed but for which there ain't no such requirement'. And kitchen sinks is on that second list. But there's a widely-read trade 'Bible', Whitfield's Guide-to-the-Regs, wot makes a big song and dance about what a good idea it is to earth a kitchen sink. It doesn't put the other side of the case - that providing a well-earthed sink to lean against (especially if you're in bare-midriff mode: middle-aged male uk.d-i-y'er on the rare hot day of summer, or fashion-conscious female young in (actual or virtual) years) you increase the harm from a touch-something-live fault. Bottom line - it's arguable both ways, and with copper piping you're unlikely not to have it earthed thru the taps anyway. If you want to either bond it explicitly to the pipework, or earth it to a nearby socket, go ahead; but you won't find any authoritative cable size to use, because the only authoritative source doesn't require it to be done. Stefek |
#15
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Bert Coules wrote:
NT, 16mm2... OK, thanks for that. ...and it must be earthed within 2m of the sink, so you may have to take a tile up to get an earth rod in as well. There's no earth anywhere near two metres of the sink in any direction including straight down. Does the sink have to have a *direct* independent connection to actual earth? The rest of the internal copper pipework is earthed back to the consumer unit (in very hefty cable, which I take to be 16mm2) and thence to the incoming supply's earth; surely it would be sufficient to bond the sink to the nearest available copper pipe? Bert http://www.bertcoules.co.uk Poor Bert, you took my reply seriously- and that of many other contributors here. There is no requirement or reason to earth a kitchen sink. I thought from my description you'd realise it was not serious. NT |
#16
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"Stefek Zaba" wrote in message ... Bert Coules wrote: I agree that on the face of it it seems an odd requirement, but it just seems simpler not to argue, really. I would be interested in an idiot's-guide explanation as to why it's necessary, if anyone would be kind enough... We've been through this multiple times - as a groups.google.com look in uk.d-i-y will show. No-one's yet been arrassed to put the Conclusion in the FAQ. There is NO requirement to earth a kitchen sink. The IEE On-Site guide goes so far as to use almost exactly those words - i.e. it doesn't just not mention sinks under 'things wot must be earthed'; after that list, it gives another list of 'things wot you might think must be earthed but for which there ain't no such requirement'. And kitchen sinks is on that second list. But there's a widely-read trade 'Bible', Whitfield's Guide-to-the-Regs, wot makes a big song and dance about what a good idea it is to earth a kitchen sink. It doesn't put the other side of the case - that providing a well-earthed sink to lean against (especially if you're in bare-midriff mode: middle-aged male uk.d-i-y'er on the rare hot day of summer, or fashion-conscious female young in (actual or virtual) years) you increase the harm from a touch-something-live fault. I have a metal sink, well two actally, and they are completly isolated from earth for this reason, It's how my dads brother died many many years ago... Sparks... |
#17
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"Stefek Zaba" wrote in message ... There is NO requirement to earth a kitchen sink. The IEE On-Site guide goes so far as to use almost exactly those words - i.e. it doesn't just not mention sinks under 'things wot must be earthed'; after that list, it gives another list of 'things wot you might think must be earthed but for which there ain't no such requirement'. And kitchen sinks is on that second list. Phew! I'll tell Spouse. When I asked him about it he said that neither of ours is earthed and he thought it was a nonsense but, he said, it WAS a requirement. It will be good to tell him that it's not :-) Mary |
#18
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Poor Bert, you took my reply seriously- and that of many other contributors here. There is no requirement or reason to earth a kitchen sink. I thought from my description you'd realise it was not serious. FWIW I didn't see any indication of you joking! A little :-) may have helped a bit! |
#19
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"Sparks" wrote in message .. . Poor Bert, you took my reply seriously- and that of many other contributors here. There is no requirement or reason to earth a kitchen sink. I thought from my description you'd realise it was not serious. FWIW I didn't see any indication of you joking! A little :-) may have helped a bit! No, it's funnier without. Well, the result usually is ... Mary :-) |
#20
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Poor Bert, you took my reply seriously...
Hey, I can't help it if I'm a naturally trusting soul. Anyone want to buy a reel of 16mm2 earth cable? Bert http://www.bertcoules.co.uk |
#21
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Stefek Zaba wrote:
There is NO requirement to earth a kitchen sink... Thanks for that. Assuming, of course, that you're not joking. Bert http://www.bertcoules.co.uk |
#22
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Stefek Zaba wrote:
There is NO requirement to earth a kitchen sink. The IEE On-Site guide goes so far as to use almost exactly those words - i.e. it doesn't just not mention sinks under 'things wot must be earthed'; after that list, it gives another list of 'things wot you might think must be earthed but for which there ain't no such requirement'. And kitchen sinks is on that second list. For the record: Page 26, section 4.6 (refers to regulation 471-08-01) There is no specific requirements in BS7671 to supplementary bond the following Kitchen pipes, sinks, or draining boards metal furniture in kitchens metal pipes and and wash hand basins in domestic locations other than bathrooms -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#23
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"Bert Coules" wrote in message ... BigWallop, Thanks for the reply. Aren't the pipes bonded? Or are they plastic? No, the internal pipework is all copper and it is bonded, but not under the kitchen sink. The connection is in the bathroom. Bert Is there no earth bonding hidden behind kitchen cupboards or even under the floor boards somewhere? The bonding straps could have been placed where the pipework enters the kitchen, rather than being close to the sink itself. Check along the full length of the pipework from the sink to where pipes disappear out of the kitchen. I would advise testing the bonding, but that is not really going to help to much, so I'll just say then, that it's worth placing a bonding strap on each of the cold and hot pipework, and then on to the sink in the kitchen. You say there are bonding points already on the pipework in the bathroom, so this shows that at least some of the pipes are connected, and it means the kitchen might also be bonded but the earthing straps and hidden somewhere. Time to get the torch out. :-) |
#24
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"Bert Coules" wrote in message ... Tim, Thanks for the reply. I never cut my cables. used to strip off insulation and then fit to earth clamp by removing the screw completely to put wire under before tightening up again.(if that makes sense!) It does, except for the bit about never cutting your cables. You must cut them to length, surely? Bert No really Bert, it means just stripping the insulation off at the point on the cable you're going to connect to the clamp. Cut around the insulation about an inch or so apart, then slit the insulation along the length between the cuts, so the insulation can be pulled apart and lifted off. You then bend the bared section of cable around the screw and insert the screw back in to the earth strap. This way the cable is never cut fully through, and so each point benefits from having the full unbroken cable to every point on the bonding loop. |
#25
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wrote in message ... On 15 May, "Mary Fisher" wrote: "Stefek Zaba" wrote in message ... There is NO requirement to earth a kitchen sink. The IEE On-Site guide goes so far as to use almost exactly those words - i.e. it doesn't just not mention sinks under 'things wot must be earthed'; after that list, it gives another list of 'things wot you might think must be earthed but for which there ain't no such requirement'. And kitchen sinks is on that second list. Phew! I'll tell Spouse. When I asked him about it he said that neither of ours is earthed and he thought it was a nonsense but, he said, it WAS a requirement. It will be good to tell him that it's not :-) Didn't edition 15 of the wiring regs insist on /anything/ metal /anywhere/ having to be earthed? Or was that only the general conception of it? We talked over breakfast about this. I hope you're not right or my desk (legs), filing cabinets, birdseed feeders, bed and gardening tools will have to be connected. I'm glad I don't wear jewellery. Now, about my fillings ... Mary -- B Thumbs Change lycos to yahoo to reply |
#26
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Sparks wrote:
NT: Poor Bert, you took my reply seriously- and that of many other contributors here. There is no requirement or reason to earth a kitchen sink. I thought from my description you'd realise it was not serious. FWIW I didn't see any indication of you joking! A little :-) may have helped a bit! I thought the idea of digging up the floor under every sink to put in earth rods, connecting them with 16mm2, and the evident implied illegality of a sink anywhere but on the ground floor would make it all obvious. As usual I was wrong. NT |
#27
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Bert Coules wrote:
Poor Bert, you took my reply seriously... Hey, I can't help it if I'm a naturally trusting soul. Anyone want to buy a reel of 16mm2 earth cable? Bert http://www.bertcoules.co.uk lol! Even funnier. I'm sure you didnt. NT |
#28
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NT,
lol! Even funnier. I'm sure you didnt. You know, thinking about it, I reckon the reason I was taken in is that I have great difficulty in visualising measurements in metric. If you'd told me to use cable that was two-thirds of an inch, I believe I'd have seen the joke straight away. Maybe. Bert http://www.bertcoules.co.uk |
#29
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"BigWallop" wrote in message . uk... "Bert Coules" wrote in message ... Tim, Thanks for the reply. I never cut my cables. used to strip off insulation and then fit to earth clamp by removing the screw completely to put wire under before tightening up again.(if that makes sense!) It does, except for the bit about never cutting your cables. You must cut them to length, surely? Bert No really Bert, it means just stripping the insulation off at the point on the cable you're going to connect to the clamp. Cut around the insulation about an inch or so apart, then slit the insulation along the length between the cuts, so the insulation can be pulled apart and lifted off. You then bend the bared section of cable around the screw and insert the screw back in to the earth strap. This way the cable is never cut fully through, and so each point benefits from having the full unbroken cable to every point on the bonding loop. Better explained than me, I was in a rush! Idea being if one connection comes loose you dont loose the bonding to all parts. |
#31
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John Rumm wrote:
Stefek Zaba wrote: There is NO requirement to earth a kitchen sink. The IEE On-Site guide goes so far as to use almost exactly those words - i.e. it doesn't just not mention sinks under 'things wot must be earthed'; after that list, it gives another list of 'things wot you might think must be earthed but for which there ain't no such requirement'. And kitchen sinks is on that second list. For the record: Page 26, section 4.6 (refers to regulation 471-08-01) There is no specific requirements in BS7671 to supplementary bond the following Kitchen pipes, sinks, or draining boards metal furniture in kitchens metal pipes and and wash hand basins in domestic locations other than bathrooms Nonetheless, kitchen sink bonding is being taught to practicing electricians, probably by NICEIC et al. A few months ago, I was one of those who asked about this, as I was having a kitchen installed and was told it was a requirement. Having asked here and got opinions from people I trust (!), I said I wasn't interested in having it done. The fitter then said he'd quote a private price, not the official one for the kitchen supply company. I bought an On Site Guide, and left it laying around. The fitter pointed out it said 2004 and these were new regulations. I confirmed this edition was the one on the IEE website. We left it at that. My wife still wasn't sure I was right. Eventually the fitter did the work anyway, at no cost, as he said he would not get the work signed off by his visiting inspector if he didn't. He was clearly aware that the work was unnecessary in principle but necessary from the point of view of his getting paid. Sure enough, when the electrician arrived to check some moved sockets, he looked for the bonding. Prompted by the fitter, he told me it was necessary for safety. One assumes that the 'self-certifying' organisations are pushing this kind of thing to increase profits from the unwary. It doesn't say much for their integrity. |
#32
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Joe wrote:
Stefek Zaba wrote: There is NO requirement to earth a kitchen sink. The IEE On-Site guide goes so far as to use almost exactly those words - i.e. it Nonetheless, kitchen sink bonding is being taught to practicing electricians, probably by NICEIC et al. snip Sure enough, when the electrician arrived to check some moved sockets, he looked for the bonding. Prompted by the fitter, he told me it was necessary for safety. One assumes that the 'self-certifying' organisations are pushing this kind of thing to increase profits from the unwary. It doesn't say much for their integrity. I doubt it's as nefarious as that, I think it's just ignorance. When I had a sparks round a few months ago to vet a rewiring job of mine, he insisted upon kitchen sink bonding (I'd deliberately not done it); have to say I didn't argue with him. This guy isn't (or at least wasn't, pre-Part P) a NICEIC member - he hates them with a vengeance actually! He didn't charge me any more for coming back to check it later, so it wasn't a profiteering exercise. David |
#33
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"Stefek Zaba" wrote in message ... There is NO requirement to earth a kitchen sink. Thinking about this, why should there be? The water pipes which are in contactwith the sink are surely earthed? Mary |
#34
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Mary Fisher wrote:
The water pipes which are in contactwith the sink are surely earthed? Unless the are plastic.... or cocooned in PTFE tape! -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#35
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"John Rumm" wrote in message ... Mary Fisher wrote: The water pipes which are in contactwith the sink are surely earthed? Unless the are plastic.... or cocooned in PTFE tape! Or maounted in the worktop like mine are! Sparks... |
#36
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"John Rumm" wrote in message ... Mary Fisher wrote: The water pipes which are in contactwith the sink are surely earthed? Unless the are plastic.... or cocooned in PTFE tape! Hmm. Hadn't thought about that - never seen it... Mary -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#37
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In article , Mary
Fisher writes "John Rumm" wrote in message ... Mary Fisher wrote: The water pipes which are in contactwith the sink are surely earthed? Unless the are plastic.... or cocooned in PTFE tape! Hmm. Hadn't thought about that - never seen it... Mary Pardon me sticking me Oar in, but I could have sworn blind that I read on some IEE website somewhere, not that long ago, that it wasn't good practice to earth the kitchen sink. Something to do with it "might not be a good idea to make a better earth than what otherwise might be" or something like that?. Course that might be total bollox but If anyone can expand on that.... -- Tony Sayer |
#38
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"tony sayer" wrote in message ... Pardon me sticking me Oar in, Oh please don't do that, they'll expect me to! Mary |
#39
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"tony sayer" wrote in message ... In article , Mary Fisher writes "John Rumm" wrote in message ... Mary Fisher wrote: The water pipes which are in contactwith the sink are surely earthed? Unless the are plastic.... or cocooned in PTFE tape! Hmm. Hadn't thought about that - never seen it... Mary Pardon me sticking me Oar in, but I could have sworn blind that I read on some IEE website somewhere, not that long ago, that it wasn't good practice to earth the kitchen sink. Something to do with it "might not be a good idea to make a better earth than what otherwise might be" or something like that?. Course that might be total bollox but If anyone can expand on that.... -- Tony Sayer (IEE Safety Extract) Voltage alone doesn't kill; it is different voltages between different parts of the body, and the resulting currents, that can prove injurious or fatal. As earlier, under certain fault conditions, parts of the earthing system in the house may not be at earth potential but significantly above it. The equipotential bonding system is intended to ensure that, if this happens, the voltage between items of equipment at arm's length never reaches a harmful level. Without equipotential bonding, a serious short circuit in the house could cause a significant voltage on the metalwork of an electric kettle while the kitchen tap close to it remained at true earth. Putting an earthing connection, an equipotential bond, between the kitchen sink and the earth terminal of the kitchen ring main prevents that dangerous voltage occurring and ensures that the tap is at the same voltage as the body of the kettle. There are two aspects to the equipotential bonding; the main bonding where services enter the building and supplementary bonding within rooms, particularly kitchens and bathrooms. Main bonding should interconnect the incoming gas, water and electricity service where these are metallic but can be omitted where the services are run in plastic, as is frequently the case nowadays. Internally, bonding should link any items which are likely to either be at earth potential or which may become live in the event of a fault and which are either gripable or sufficiently large that they can contact a significant part of the body. Small parts, other than those likely to be gripped, are ignored because the instinctive reaction to a shock is muscular contraction, which will break the circuit. |
#40
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On Sun, 15 May 2005 21:24:06 +0100, Stefek Zaba
wrote: providing a well-earthed sink to lean against [...] fashion-conscious female young in (actual or virtual) years) you increase the harm from a touch-something-live fault. Rename that as the Chav-O-Cutor and I think you have a winner! |
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