Sorry, I should have said does the theory say they should go, rather than the regs. But thanks for clarifying as I didn't have the reg wording available.
If high currents were to flow in a bonding conductor, it would presumably be from the provided earth (TN or TT) to an extraneous-c-p. That is a 'one conductor' situation, with no other conductor carrying a 'balancing return current'.
That's not really one conductor if the MET is in the CU, it's two. I don't understand how you can have a one conductor situation at all, the current can't enter the CU without leaving. One conductor is the bonding conductor entering the CU and as you say, the other is the main earth connecting to the supplier earth. They balance each other (I wouldn't like to say which is "flow" and which is "return" though.
I would not have thought that high currents in either CPCs/Earthing Conductors or Main Bonding conductors are likely to persist for long enough for the effects of eddy currents to be an appreciable concern.
I thought that was one of the reasons the bonding in PME had to be large, because some of the neutral current in the whole network may be diverted through the bonding.
That's not really one conductor if the MET is in the CU, it's two. I don't understand how you can have a one conductor situation at all, the current can't enter the CU without leaving. One conductor is the bonding conductor entering the CU and as you say, the other is the main earth connecting to the supplier earth. They balance each other (I wouldn't like to say which is "flow" and which is "return" though.
True - so that's an argument for requiring that the Earthing Conductor and all Main Bonding conductors go through the same hole - but not, from that point of view, necessarily the same hole through which the live (L+N) tails go.
However, given that, as I said before, there is an argument for the main Earthing Conductor going through the same hole as the L & N supply tails, we seem to be moving to a conclusion that all four (L + N + Earthing Conductor + Main Bonding Conductor{s}) should go through the same hole.
All of my comments really only relate to TN installations. With TT, the amount of current that can flow in bonding conductors is usually probably far too small to be of any great concern (in terms of eddy currents in enclosures).
I thought that was one of the reasons the bonding in PME had to be large, because some of the neutral current in the whole network may be diverted through the bonding.
Indeed - but it doesn't necessarily have to be in the external parts of the network - the neutral current arising from just the installation itself could, in some circumstances, be pretty high.
Yes that is what I was also thinking but I think it would require the tails to be a bit longer because of the extra loop to go in from the side, but I can't change the tails with out breaking the new seal on the meter.
It is also possible to come in further to the left from underneath as there are two 32mm knockouts, but the one furthest to the left I would like to use, is sort of in the way between the 2 conduits coming in as it is at the moment.
But these two conduits I want to change to 20mm anyway so I could change them to enter via the next appropriate hole.
Yes that is what I was also thinking but I think it would require the tails to be a bit longer because of the extra loop to go in from the side, but I can't change the tails with out breaking the new seal on the meter.
As I said before, if it were necessary, you could 'extend the tails' (without needing to break any seals) by use of 'Henley blocks' etc. - although such 'unnecessary' additional joints are not ideal.
If you had to go down that route, I suppose you could extend the tails with a Henley block as a temporary measure, and then arrange for new, longer, tails to be substituted when you have your meter replaced.
That is very true and that is why I brought it up here as I don't know the regulations whereas all of you are very experienced in this area and I was wondering what you thought about it.
There is so much misinformation these days on the internet its hard to know what is true and what isn't.
That is why all your feedback on this forum is highly valued
And that does say they have to go through the same hole. I wasn't sure if the regs said that, or if (as they could well have done) they only required conductors to be arranged to avoid problems of electromagnetic heating.
So there's another thing your bungling soi-disant electrician bungled.
Fortunately, as we know, the currents in your cables will never be high enough to cause any significant heating.
I decided to lay a few more data cables to my mini servers in the kitchen and decided to make a small channel in the plaster behind the skirting board.
The plaster was a bit crumbly and came off quite easily but I discovered these 2 electric cables and now that I look at it is is obvious in hind sight as you can see the small patch of plastering that has been redone.
Lucky I didn't cut through them with a chisel.
It's just typical as I take a break from looking at the electrics to do something else and could have ended up with a shock.
God knows where these cables come from or go too as I was sure I had found and traced every socket.
What an IDIOT I am, I should have used a metal/ac finder first to check although I thought just taking off 1 cm of plaster was safe especially since there is nothing in line with this. The only thing on that wall is the light switch which is about 2 feet to the right.
And it is live as well as just tested it.
I wonder what they are? They look horribly like meter tails, which is a scary thought. Looks like your recent bungler was not the first one to bungle in your flat.
I wonder what they are? They look horribly like meter tails, which is a scary thought. Looks like your recent bungler was not the first one to bungle in your flat.
Exactly that is why I thought it was OK as its not a safe zone so not allowed with protective casing.
They are the same as the singles run through the conduit so I don't think they are tails.
Oh well out with my new endoscope I just got from Amazon and have a little explore under the floor near that area to see if I can see where they are going.
The kitchen is really annoying as someone laid a very large sheet of timber on top of the floor and I really didn't want to cut it up but it looks as if I will have too at some point and remove the tiling too.
I know the old lady I bought this flat from had some so called handy man do jobs for her and I am sure it was him who did it.
So unfortunately anything is possible .
Flanged couplers are not supplied with serrated washers but just the lead washer. If you wanted serrated washers you would have to purchase them separately.
Flanged couplers are always used here when entering accessories/trunking.
Thanks I will have a look, the tiles I was thinking will have to come up as I think the wires go vertically up the wall just below the tiles with no protection or earth.
So I can't leave it like that as its not safe so either I can disconnect the cable from the consumer unit or redo it.
Hopefully its only supplying 2 sockets in the kitchen, so it can be disconnected when a new ring is put in for the kitchen.
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