Continuity between neutral and earth

Yes only the MCB was switched off. Rest of the CU was on
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 07/12/2017 13:11, snipped-for-privacy@yahoo.co.uk wrote:

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.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@yahoo.co.uk wrote:

If you turn off the main switch (which is double pole) the continuity between earth and neutral should go away. If it doesn't there is probably a fault on a circuit - but not necessarily the one you were working on.
Mike
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wednesday, 6 December 2017 20:31:35 UTC, snipped-for-privacy@yahoo.co.uk wrote:

cutting the return from one socket and then connecting each side of the ext ended ring to one of the cut ends.

corresponding pairs of wire). I have just connected it to the main ring an d 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 a ppear 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 connect ed together in at least one place is a person who is not qualified to do su ch work and the resulting installation is at risk of being in breach of the Building Regulations. See http://www.gutenberg.org/files/27182/27182-h/27 182-h.htm, VI.
--
(c) Dr. S. Lartius, UK. Gmail: dr.s.lartius@ |

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 07/12/2017 11:20, snipped-for-privacy@gmail.com wrote:

Erroneous statement followed by a non sequitur... Mmmm useful ;-)
--
Cheers,

John.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thursday, 7 December 2017 13:35:22 UTC, John Rumm wrote:

The OP reported that connectivity had, to his surprise, been found between his neutral and earth wires. It is a requirement that the local ne utral wires must, somehow, be electrically connected to the terrestrial Ear th, and it is a requirement that the local earth wires must, somehow, be el ectrically connected to the terrestrial Earth. Therefore the reported conn ectivity 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 metal lic 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@ |

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Saturday, 9 December 2017 12:46:05 UTC, snipped-for-privacy@gmail.com wrote:

neutral wires must, somehow, be electrically connected to the terrestrial E arth, and it is a requirement that the local earth wires must, somehow, be electrically connected to the terrestrial Earth. Therefore the reported co nnectivity is required to exist, and so should be expected; it occurs due t o at least one connection, somewhere; such a connection may be man-made met allic or by way of the terrestrial Earth (or by any other reliable means, i f any is possible).
In fairness I did once see an installation that must have been relying on a n extraterrestrial earth :)
NT
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 09/12/2017 12:46, snipped-for-privacy@gmail.com wrote:

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.

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.

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.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
[48 lines snipped]

Precisely.
--
Today is Pungenday, the 51st day of The Aftermath in the YOLD 3183
Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, but when breaking into a ring to add something, he doesn’t 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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That’s wrong when the connection is back in the sub station.

Nope.

Irrelevant to your claim.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thursday, 7 December 2017 22:21:49 UTC, Rod Speed wrote:

You should, before responding, read carefully what has previously been writ ten, 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".

Yes. A person who does not know that the voltage and the resistance betwee n neutral and earth should each be small is a person who is likely not to k now all of the proper safe wiring practices that the Regulations require.

--
(c) John Stockton, near London, UK. Using Google, no spell-check. |
Mail: J.R.""""""""@physics.org - or as Reply-To |
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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...
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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 snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 09/12/2017 12:35, Dave Plowman (News) wrote:

If you short Neutral and Earth supply side of the RCD, it should not trip the RCD.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No shit 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 snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Get stuffed.

That’s not true of all wiring systems.

Yep, perfectly safe even if you don’t understand whether there should be continuity between earth and neutral or not.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote

Did that, its stays pig ignorant shit no matter how often its carefully read and thought about.

You quite sure you aint actually one of those rocket scientist terminal fuckwits ?

Yes, you were that pig ignorant and stupid.

Nope.

You havent established that he doesn’t know that.

Even sillier than you usually manage, and that’s saying something.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.