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UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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#1
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Continuity between neutral and earth
Hi All
I have broken into a ring main to extend it to another room. Essentially cutting the return from one socket and then connecting each side of the extended ring to one of the cut ends. I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. Any ideas? Thanks Lee |
#2
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Continuity between neutral and earth
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#3
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Continuity between neutral and earth
leenowell wrote:
Live is ok but it seems that neutral (blue) and earth now have continuity. Depending on your earthing arrangement, this is probably normal, do you know type of supply you have? http://wiki.diyfaq.org.uk/index.php/Earthing_Types The type determines whether or where your neutral meets earth ... |
#4
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Continuity between neutral and earth
Thanks both. Looking at the wiki it looks like it is tn C's.
The incoming wire goes to a fused black box and outbof that comes over neutral and earth. Earth goes to cu and the live and neutral go to the meter and then to the cu via a new isolation switch. |
#5
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Continuity between neutral and earth
leenowell wrote:
Looking at the wiki it looks like it is tn C's. The incoming wire goes to a fused black box and outbof that comes over neutral and earth. You're *probably* correct, though depending what connections are made inside the black box (cutout) it could be TNC-S or TN-S, as some of the photos show (those with/without links from N to E inside the box). Earth goes to cu and the live and neutral go to the meter and then to the cu via a new isolation switch. |
#6
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Continuity between neutral and earth
The black box has the electric company fuse in it so don't want to take the cover off to check . The incoming cable comes in from the bottom earth comes out to the right and live and neutral out to the too where the fuse is.. In coming is a single black cable.
Does that help in any way. Would both give the symptoms I describe? |
#7
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Continuity between neutral and earth
Hi
Yes I think it is TN CS. This picture looks very much like my installation http://wiki.diyfaq.org.uk/index.php/File:PME1.jpg So sounds like neutral and earth continuity is correct for my installation. Thanks for your help Lee |
#9
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Continuity between neutral and earth
On Wednesday, 6 December 2017 20:31:35 UTC, wrote:
Hi All I have broken into a ring main to extend it to another room. Essentially cutting the return from one socket and then connecting each side of the extended ring to one of the cut ends. I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. Any ideas? Thanks Lee Neutral and earth are bonded together back at the substation. It's important that this is the only place they are bonded. |
#10
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Continuity between neutral and earth
On 07/12/2017 08:24, wrote:
Hi Yes I think it is TN CS. This picture looks very much like my installation http://wiki.diyfaq.org.uk/index.php/File:PME1.jpg So sounds like neutral and earth continuity is correct for my installation. N&E continuity (of some sort) is correct for the vast majority of installations (assuming you are doing the test with the circuit connected to the CU[1]). With TN-C-S the link is in your property. With TN-S its back at a substation. With TT its via the general mass of the earth, and may have a higher resistance, but is still good enough to make a continuity test "pass" in many cases. [1] If you want to test your "new" combined circuit in isolation, then you need to disconnect it at the CU end and test there. That way you will be free of the influences of the supply itself and any EQ bonding connections. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#11
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Continuity between neutral and earth
On 07/12/2017 09:44, harry wrote:
On Wednesday, 6 December 2017 20:31:35 UTC, wrote: Hi All I have broken into a ring main to extend it to another room. Essentially cutting the return from one socket and then connecting each side of the extended ring to one of the cut ends. I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. Any ideas? Thanks Lee Neutral and earth are bonded together back at the substation. That is true. It's important that this is the only place they are bonded. That is certainly not true for TN-C-S (PME) supplies which are the default "standard" for installs these days. (the clue is in the "M"!) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#12
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Continuity between neutral and earth
In article ,
Brian Gaff wrote: I was always told that Neutral was supposed to be earth, or almost so. Otherwise we would have two lives. Brian It's earth at the substaion, but its volage wrt earth at your home will depend on how evenly the phases are loaded. 10v wrt earth isn't uncommon. -- from KT24 in Surrey, England |
#13
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Continuity between neutral and earth
In article ,
wrote: I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. Assuming you are testing with the main switch off (double pole) you have a fault. If testing with only the MCB etc (single pole) off, normal. -- *Real women don't have hot flashes, they have power surges. Dave Plowman London SW To e-mail, change noise into sound. |
#14
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Continuity between neutral and earth
On Thu, 7 Dec 2017 09:23:40 -0000, "Brian Gaff"
wrote: I was always told that Neutral was supposed to be earth, or almost so. Otherwise we would have two lives. Brian One of which would then be a negative wouldn't it? In the past I think some people referred to the black , later blue wire in domestic wiring as the negative which was wrong but possibly influenced with tinkering with cars where batteries have a positive and negative pole, or maybe for old timers it was a hangover from the days of DC mains. The yellow 110 volt plugs intended for use with transformers in the UK to give a 55-0-55 volt supply usaully have both pins identified with a moulded L rather than an L and an N but I reckon few people using or even wiring one have noticed. G.Harman |
#15
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Continuity between neutral and earth
On Wednesday, 6 December 2017 20:31:35 UTC, wrote:
I have broken into a ring main to extend it to another room. Essentially cutting the return from one socket and then connecting each side of the extended ring to one of the cut ends. I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work and the resulting installation is at risk of being in breach of the Building Regulations. See http://www.gutenberg.org/files/27182...-h/27182-h.htm, VI. -- (c) Dr. S. Lartius, UK. Gmail: dr.s.lartius@ | |
#16
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Continuity between neutral and earth
On Thursday, 7 December 2017 11:10:34 UTC, wrote:
On Thu, 7 Dec 2017 09:23:40 -0000, "Brian Gaff" wrote: I was always told that Neutral was supposed to be earth, or almost so. Otherwise we would have two lives. Brian One of which would then be a negative wouldn't it? In the past I think some people referred to the black , later blue wire in domestic wiring as the negative which was wrong but possibly influenced with tinkering with cars where batteries have a positive and negative pole, or maybe for old timers it was a hangover from the days of DC mains. The yellow 110 volt plugs intended for use with transformers in the UK to give a 55-0-55 volt supply usaully have both pins identified with a moulded L rather than an L and an N but I reckon few people using or even wiring one have noticed. G.Harman Dc mains used the 2 phase 3 wire system, so half of end users got + and half got -ve dc supplied. NT |
#17
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Continuity between neutral and earth
Yes only the MCB was switched off. Rest of the CU was on
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#18
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Continuity between neutral and earth
On 07/12/2017 13:11, wrote:
Yes only the MCB was switched off. Rest of the CU was on Yup, that only isolates the live. N is still connected to the neutral bus bar and hence the supply neutral via the main switch. E would be connected to the supply neutral either at the PME head end (and multiple other places) or at the transformer if your supply was TN-S. (it will also be connected to an independent earth in the case of TT or any installation with main equipotential bonds to incoming metallic services). -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#19
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Continuity between neutral and earth
On 07/12/2017 11:20, wrote:
ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work and the resulting installation is at risk of being in breach of the Building Regulations. See Erroneous statement followed by a non sequitur... Mmmm useful ;-) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#21
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Continuity between neutral and earth
wrote
wrote I have broken into a ring main to extend it to another room. Essentially cutting the return from one socket and then connecting each side of the extended ring to one of the cut ends. I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work Thats wrong when the connection is back in the sub station. and the resulting installation is at risk of being in breach of the Building Regulations. Nope. See http://www.gutenberg.org/files/27182...-h/27182-h.htm, VI. Irrelevant to your claim. |
#22
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Continuity between neutral and earth
On Thursday, 7 December 2017 22:21:49 UTC, Rod Speed wrote:
wrote wrote I have broken into a ring main to extend it to another room. Essentially cutting the return from one socket and then connecting each side of the extended ring to one of the cut ends. I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work Thats wrong when the connection is back in the sub station. You should, before responding, read carefully what has previously been written, and think about it. When neutral and earth are connected together at the sub-station, they are connected together at that place. I did NOT put anything about "connected together within the premises". and the resulting installation is at risk of being in breach of the Building Regulations. Nope. Yes. A person who does not know that the voltage and the resistance between neutral and earth should each be small is a person who is likely not to know all of the proper safe wiring practices that the Regulations require. See http://www.gutenberg.org/files/27182...-h/27182-h.htm, VI. Irrelevant to your claim. -- (c) John Stockton, near London, UK. Using Google, no spell-check. | Mail: - or as Reply-To | |
#23
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Continuity between neutral and earth
Stop bickering. I mean, its supposed to be earthed, where its earthed only
affects the wiring between that earth and the one that should be down the line toward the substation, so who really cares? Brian -- ----- - This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please! wrote in message ... On Thursday, 7 December 2017 22:21:49 UTC, Rod Speed wrote: wrote wrote I have broken into a ring main to extend it to another room. Essentially cutting the return from one socket and then connecting each side of the extended ring to one of the cut ends. I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work That's wrong when the connection is back in the sub station. You should, before responding, read carefully what has previously been written, and think about it. When neutral and earth are connected together at the sub-station, they are connected together at that place. I did NOT put anything about "connected together within the premises". and the resulting installation is at risk of being in breach of the Building Regulations. Nope. Yes. A person who does not know that the voltage and the resistance between neutral and earth should each be small is a person who is likely not to know all of the proper safe wiring practices that the Regulations require. See http://www.gutenberg.org/files/27182...-h/27182-h.htm, VI. Irrelevant to your claim. -- (c) John Stockton, near London, UK. Using Google, no spell-check. | Mail: - or as Reply-To | |
#24
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Continuity between neutral and earth
In article ,
Brian Gaff wrote: Stop bickering. I mean, its supposed to be earthed, where its earthed only affects the wiring between that earth and the one that should be down the line toward the substation, so who really cares? It's not that simple. If you short local earth to neutral here, it will trip the RCD. Neutral and earth should only be connected together where they are designed to be. Which will vary according to your type of mains supply. With my older installation it isn't done in my house. Presumably at the local sub station. -- *(on a baby-size shirt) "Party -- my crib -- two a.m Dave Plowman London SW To e-mail, change noise into sound. |
#25
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Continuity between neutral and earth
On Thursday, 7 December 2017 13:35:22 UTC, John Rumm wrote:
On 07/12/2017 11:20, SL wrote: ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work and the resulting installation is at risk of being in breach of the Building Regulations. See Erroneous statement followed by a non sequitur... Mmmm useful ;-) The OP reported that connectivity had, to his surprise, been found between his neutral and earth wires. It is a requirement that the local neutral wires must, somehow, be electrically connected to the terrestrial Earth, and it is a requirement that the local earth wires must, somehow, be electrically connected to the terrestrial Earth. Therefore the reported connectivity is required to exist, and so should be expected; it occurs due to at least one connection, somewhere; such a connection may be man-made metallic or by way of the terrestrial Earth (or by any other reliable means, if any is possible). -- (c) Dr. S. Lartius, UK. Gmail: dr.s.lartius@ | |
#26
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Continuity between neutral and earth
On Saturday, 9 December 2017 12:46:05 UTC, wrote:
On Thursday, 7 December 2017 13:35:22 UTC, John Rumm wrote: On 07/12/2017 11:20, SL wrote: ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work and the resulting installation is at risk of being in breach of the Building Regulations. See Erroneous statement followed by a non sequitur... Mmmm useful ;-) The OP reported that connectivity had, to his surprise, been found between his neutral and earth wires. It is a requirement that the local neutral wires must, somehow, be electrically connected to the terrestrial Earth, and it is a requirement that the local earth wires must, somehow, be electrically connected to the terrestrial Earth. Therefore the reported connectivity is required to exist, and so should be expected; it occurs due to at least one connection, somewhere; such a connection may be man-made metallic or by way of the terrestrial Earth (or by any other reliable means, if any is possible). In fairness I did once see an installation that must have been relying on an extraterrestrial earth NT |
#27
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Continuity between neutral and earth
On 09/12/2017 12:46, wrote:
On Thursday, 7 December 2017 13:35:22 UTC, John Rumm wrote: On 07/12/2017 11:20, SL wrote: ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work and the resulting installation is at risk of being in breach of the Building Regulations. See Erroneous statement followed by a non sequitur... Mmmm useful ;-) It is a requirement that the local neutral wires must, somehow, be electrically connected to the terrestrial Earth, and it is a requirement that the local earth wires must, somehow, be electrically connected to the terrestrial Earth. That is a somewhat different statement from "neutral and earth MUST be connected together in at least one place". Even then its still questionable. With a TT supply[1] its fair to assume the neutral will be connected to earth at the transformer. However that may be the only place, and there may be no direct connection to the neutral to the customer's earth. Their earth should be independently connected to earth locally, however that may show hundreds of ohms resistance to the earth point on the supply and hence to the neutral at entry to the premises. (and that obviously ignores things like IT setups with gensets etc). [1] Yes, I know the OP does not have one of these, but you made a blanket statement without qualification. Therefore the reported connectivity is required to exist, and so Low impedance connectivity as described by the OP is not *required* to exist (since it may not be possible), and on TT installs may not. should be expected; it occurs due to at least one connection, somewhere; such a connection may be man-made metallic or by way of the terrestrial Earth (or by any other reliable means, if any is possible). Indeed, and that is different from what you said previously. I also took issue with the assertion that someone not intimately familiar with earthing systems would not be "qualified" to work on an electrical system. I have met a number of professionally qualified electricians that only have a tenuous grasp on such things, but they can still produce good quality work by applying the rules as specified. I would assert that its perfectly possible to do a safe and compliant extension to a socket circuit, and know nothing at all about earthing systems beyond the need to connect the wires to the socket and test the continuity when done (as I did many times when I was 12, and would not have known my earth loop impedance from my elbow!) The final "at risk of being in breach of the Building Regulations" was a rather mealy mouthed straw man IMHO. One could argue that everyone is "at risk" of being in breach of one building regulation or another, but there was nothing in the OPs post to suggest that was likely here - the fact that he was asking questions about his observations that obviously resulted from testing his installation should offer reassurance that improper work would be much less likely rather than more. (here endeth the rant about people offering unhelpful criticism in place of useful advice) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#28
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Continuity between neutral and earth
On Thu, 07 Dec 2017 09:51:24 +0000, John Rumm wrote:
On 07/12/2017 08:24, wrote: Hi Yes I think it is TN CS. This picture looks very much like my installation http://wiki.diyfaq.org.uk/index.php/File:PME1.jpg So sounds like neutral and earth continuity is correct for my installation. N&E continuity (of some sort) is correct for the vast majority of installations (assuming you are doing the test with the circuit connected to the CU[1]). With TN-C-S the link is in your property. With TN-S its back at a substation. With TT its via the general mass of the earth, and may have a higher resistance, but is still good enough to make a continuity test "pass" in many cases. [1] If you want to test your "new" combined circuit in isolation, then you need to disconnect it at the CU end and test there. That way you will be free of the influences of the supply itself and any EQ bonding connections. This looks to be another advantage of RCBOs. I had them fitted because I kept knocking the main breaker out with earth/ neutral contact when changing stuff. Isolating both live and neutral can have advantages when you want to keep most of the house powered up when you work on one circuit. Cheers Dave R -- AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64 --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
#29
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Continuity between neutral and earth
David wrote:
This looks to be another advantage of RCBOs Isolating both live and neutral can have advantages when you want to keep most of the house powered up when you work on one circuit. Except most RCBOs only break the live pole, the neutral passes through them, but only for sensing, there are double pole RCBOs but you'd have to go hunting for them |
#30
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Continuity between neutral and earth
On 09/12/2017 12:35, Dave Plowman (News) wrote:
In article , Brian Gaff wrote: Stop bickering. I mean, its supposed to be earthed, where its earthed only affects the wiring between that earth and the one that should be down the line toward the substation, so who really cares? It's not that simple. If you short local earth to neutral here, it will trip the RCD. Neutral and earth should only be connected together where they are designed to be. Which will vary according to your type of mains supply. With my older installation it isn't done in my house. Presumably at the local sub station. If you short Neutral and Earth supply side of the RCD, it should not trip the RCD. |
#31
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Continuity between neutral and earth
On 10/12/2017 14:54, David wrote:
On Thu, 07 Dec 2017 09:51:24 +0000, John Rumm wrote: On 07/12/2017 08:24, wrote: Hi Yes I think it is TN CS. This picture looks very much like my installation http://wiki.diyfaq.org.uk/index.php/File:PME1.jpg So sounds like neutral and earth continuity is correct for my installation. N&E continuity (of some sort) is correct for the vast majority of installations (assuming you are doing the test with the circuit connected to the CU[1]). With TN-C-S the link is in your property. With TN-S its back at a substation. With TT its via the general mass of the earth, and may have a higher resistance, but is still good enough to make a continuity test "pass" in many cases. [1] If you want to test your "new" combined circuit in isolation, then you need to disconnect it at the CU end and test there. That way you will be free of the influences of the supply itself and any EQ bonding connections. This looks to be another advantage of RCBOs. I had them fitted because I kept knocking the main breaker out with earth/ neutral contact when changing stuff. Isolating both live and neutral can have advantages when you want to keep most of the house powered up when you work on one circuit. Take care with that though since most RCBOs are only single pole switches (even if they are connected to neutral to allow for current imbalance sensing). Hence they can't provide isolation of the circuit. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#32
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Continuity between neutral and earth
wrote in message ... On Thursday, 7 December 2017 22:21:49 UTC, Rod Speed wrote: wrote wrote I have broken into a ring main to extend it to another room. Essentially cutting the return from one socket and then connecting each side of the extended ring to one of the cut ends. I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work Thats wrong when the connection is back in the sub station. You should, before responding, read carefully what has previously been written, and think about it. Did that, its stays pig ignorant **** no matter how often its carefully read and thought about. When neutral and earth are connected together at the sub-station, they are connected together at that place. You quite sure you aint actually one of those rocket scientist terminal ****wits ? I did NOT put anything about "connected together within the premises". Yes, you were that pig ignorant and stupid. and the resulting installation is at risk of being in breach of the Building Regulations. Nope. Yes. Nope. A person who does not know that the voltage and the resistance between neutral and earth should each be small You havent established that he doesnt know that. is a person who is likely not to know all of the proper safe wiring practices that the Regulations require. Even sillier than you usually manage, and thats saying something. See http://www.gutenberg.org/files/27182...-h/27182-h.htm, VI. Irrelevant to your claim. |
#33
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Continuity between neutral and earth
Brian Gaff wrote
Stop bickering. Get stuffed. I mean, its supposed to be earthed, where its earthed only affects the wiring between that earth and the one that should be down the line toward the substation, That’s not true of all wiring systems. so who really cares? Yep, perfectly safe even if you don’t understand whether there should be continuity between earth and neutral or not. wrote in message ... On Thursday, 7 December 2017 22:21:49 UTC, Rod Speed wrote: wrote wrote I have broken into a ring main to extend it to another room. Essentially cutting the return from one socket and then connecting each side of the extended ring to one of the cut ends. I test the extended ring and it was sound (ie only continuity between the corresponding pairs of wire). I have just connected it to the main ring and did a quick continuity check. Live is ok but it seems that neutral (blue) and earth now have continuity. Given I tested the extended ring it would appear that the original ring suffered this problem. However if this was the case wouldn't the RCd at the MCU have tripped before. ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work That's wrong when the connection is back in the sub station. You should, before responding, read carefully what has previously been written, and think about it. When neutral and earth are connected together at the sub-station, they are connected together at that place. I did NOT put anything about "connected together within the premises". and the resulting installation is at risk of being in breach of the Building Regulations. Nope. Yes. A person who does not know that the voltage and the resistance between neutral and earth should each be small is a person who is likely not to know all of the proper safe wiring practices that the Regulations require. See http://www.gutenberg.org/files/27182...-h/27182-h.htm, VI. Irrelevant to your claim. -- (c) John Stockton, near London, UK. Using Google, no spell-check. | Mail: - or as Reply-To | |
#34
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Continuity between neutral and earth
wrote in message ... On Thursday, 7 December 2017 13:35:22 UTC, John Rumm wrote: On 07/12/2017 11:20, SL wrote: ISTM that a person who does not know that neutral and earth MUST be connected together in at least one place is a person who is not qualified to do such work and the resulting installation is at risk of being in breach of the Building Regulations. See Erroneous statement followed by a non sequitur... Mmmm useful ;-) The OP reported that connectivity had, to his surprise, been found between his neutral and earth wires. It is a requirement that the local neutral wires must, somehow, be electrically connected to the terrestrial Earth, and it is a requirement that the local earth wires must, somehow, be electrically connected to the terrestrial Earth. Therefore the reported connectivity is required to exist, and so should be expected; it occurs due to at least one connection, somewhere; such a connection may be man- made metallic or by way of the terrestrial Earth (or by any other reliable means, if any is possible). Yes, but when breaking into a ring to add something, he doesnt need to know about the required connection between earth and neutral to do that safely. In spades when it happens back in the sub station. |
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Continuity between neutral and earth
In article ,
Fredxx wrote: On 09/12/2017 12:35, Dave Plowman (News) wrote: In article , Brian Gaff wrote: Stop bickering. I mean, its supposed to be earthed, where its earthed only affects the wiring between that earth and the one that should be down the line toward the substation, so who really cares? It's not that simple. If you short local earth to neutral here, it will trip the RCD. Neutral and earth should only be connected together where they are designed to be. Which will vary according to your type of mains supply. With my older installation it isn't done in my house. Presumably at the local sub station. If you short Neutral and Earth supply side of the RCD, it should not trip the RCD. No **** sherlock? Why would anyone actually do that when fitting a new socket, etc? -- *Why is the man who invests all your money called a broker? Dave Plowman London SW To e-mail, change noise into sound. |
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