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boiler earthing?
Hello,
My old (oil fired) boiler had a 4mm^2 (ish) earth wire that ran from the copper oil line back to the CU. When the (non-oftec) plumber recently installed the new boiler, this was not reconnected. I am having an oftec plumber coming to sign everything off. Should I connect the earth before he comes and for my own safety? The boiler is earthed but only through the 6A flex. In my last house the (gas) boiler had all the pipes cross bonded immediately beneath it. None of the pipes going to or from this boiler are. I don't think the CH pipes are earthed anywhere. Should they be? Thanks, Stephen. |
boiler earthing?
In article ,
Stephen writes: Hello, My old (oil fired) boiler had a 4mm^2 (ish) earth wire that ran from the copper oil line back to the CU. That's the service bonding. Nowadays, it should be 10mm˛, IIRC. When the (non-oftec) plumber recently installed the new boiler, this was not reconnected. I am having an oftec plumber coming to sign everything off. Should I connect the earth before he comes and for my own safety? I would have thought so, but I'm not expert in oil fired boiler matters and any special requirements on them. The boiler is earthed but only through the 6A flex. In my last house the (gas) boiler had all the pipes cross bonded immediately beneath it. None of the pipes going to or from this boiler are. I don't think the CH pipes are earthed anywhere. Should they be? They probably are in or adjacent to the bathroom -- that's where it's normally done. -- Andrew Gabriel [email address is not usable -- followup in the newsgroup] |
boiler earthing?
"Stephen" wrote in message ... Hello, My old (oil fired) boiler had a 4mm^2 (ish) earth wire that ran from the copper oil line back to the CU. When the (non-oftec) plumber recently installed the new boiler, this was not reconnected. I am having an oftec plumber coming to sign everything off. Should I connect the earth before he comes and for my own safety? The boiler is earthed but only through the 6A flex. In my last house the (gas) boiler had all the pipes cross bonded immediately beneath it. None of the pipes going to or from this boiler are. I don't think the CH pipes are earthed anywhere. Should they be? Thanks, Stephen. My OFTEC oil installer fitted my boiler but didn't bond the incoming oil pipe, despite me querrying it. My NICEIC electrician certifying the whole electrical installation insisted on 10mm bonding back to the main earth point at the CU. Mind you I can (and actually have in a previous posting) cite several errors of fact on his certificate !!!) The boiler per se is only earthed via the copper plumbing which is bonded and its own electrical connection 2.5mm earth. AWEM |
boiler earthing?
Stephen wrote:
My old (oil fired) boiler had a 4mm^2 (ish) earth wire that ran from the copper oil line back to the CU. That would be the main equipotential bond for the incoming service (i.e. oil pipe) When the (non-oftec) plumber recently installed the new boiler, this was not reconnected. I am having an oftec plumber coming to sign everything off. Should I connect the earth before he comes and for my own safety? All incoming services in metallic pipes should be included in the main equipotential bonding. For TN-C-S and TN-S installations this is usually 10mm^2 earth single. For TT it can be 6mm^2 See: http://wiki.diyfaq.org.uk/index.php?...ng_and_Bonding The boiler is earthed but only through the 6A flex. That is fine. In my last house the (gas) boiler had all the pipes cross bonded immediately beneath it. None of the pipes going to or from this boiler are. I don't think the CH pipes are earthed anywhere. Should they be? Where is the boiler? Where was it in the last place? Generally speaking you would expect to see supplementary equipotential bonding in places that pose an special risk (bath / shower rooms, pool / saunas etc). There is no harm in have supplementary bonding between its connections, however there is in many cases no absolute requirement for it. Note that supplementary bonds do not need to be either earthed, or connected back to the main CU earth terminal. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
boiler earthing?
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boiler earthing?
On Sun, 4 Jan 2009 18:31:05 -0000, "Andrew Mawson"
wrote: My OFTEC oil installer fitted my boiler but didn't bond the incoming oil pipe, despite me querrying it. My NICEIC electrician certifying the whole electrical installation insisted on 10mm bonding back to the main earth point at the CU My OFTEC chap didn't comment that it's not connected. However since the wire is there I will connect it. I'll have to be careful though as I assume the 10mm micorobore pipe is more easily damaged if I overtighten the clamp. Thanks. |
boiler earthing?
On Sun, 04 Jan 2009 21:12:29 +0000, John Rumm
wrote: Where is the boiler? Where was it in the last place? Generally speaking you would expect to see supplementary equipotential bonding in places that pose an special risk (bath / shower rooms, pool / saunas etc). There is no harm in have supplementary bonding between its connections, however there is in many cases no absolute requirement for it. Note that supplementary bonds do not need to be either earthed, or connected back to the main CU earth terminal. It is in the kitchen, exactly where the old one was. Thinking about it it's all copper pipe around the boiler but after 2 metres it turns plastic, so I'm not sure that bonding would do much, except in the immediate area of the boiler. Is supplemental bonding supposed to be 10mm^2 too? I am not going to do it (unless you tell me otherwise) but I ask out of curiosity. Thanks. |
boiler earthing?
Stephen wrote:
On Sun, 04 Jan 2009 21:12:29 +0000, John Rumm wrote: Where is the boiler? Where was it in the last place? Generally speaking you would expect to see supplementary equipotential bonding in places that pose an special risk (bath / shower rooms, pool / saunas etc). There is no harm in have supplementary bonding between its connections, however there is in many cases no absolute requirement for it. Note that supplementary bonds do not need to be either earthed, or connected back to the main CU earth terminal. It is in the kitchen, exactly where the old one was. Thinking about it it's all copper pipe around the boiler but after 2 metres it turns plastic, so I'm not sure that bonding would do much, except in the immediate area of the boiler. In "special locations" (of which a kitchen is *not* one - part P lumps it in with them, but the wiring regs do not), the question to ask, is are the pipes capable of introducing a potential into the room from elsewhere. In you case it sounds like the answer is "no". To quote the OSG (16th edtn): "There is no specific requirement in BS 7671 to supplementary bond the following kitchen pipes, sinks or draining boards metal furniture in kitchens metal pipes and wash hand basins in domestic locations other than bathrooms." Is supplemental bonding supposed to be 10mm^2 too? I am not going to do it (unless you tell me otherwise) but I ask out of curiosity. Where there is no mechanical protection for the bonding conductors, 4.0mm is commonly used. Where you are bonding a circuit protective conductor, then you should not use a smaller CSA wire than that of the CPC - however domestic wires with CPCs larger than 4.0mm are not common (only 16mm^2 for T&E) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
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