Moving consumer unit more than 3 metres from meter

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Hi all,

I'm looking for some advice.

My consumer unit is in a really awkward place at the moment. It is on the kitchen wall. I'd like to move it if possible because we are having a new kitchen put in and it's not aesthetically pleasing.

I have attached a crude drawing of the consumer unit and where I intend to place it.

As I understand it, if the consumer unit is moved more than 3 metres away from the meter, a switched fuse must be installed. Is this correct?

Looking at my drawing, how would you go about moving the consumer unit?

My thinking is that I run the tails and earth from the meter into a switched fuse unit and place it where the consumer is at the moment (the switched fuse unit can be boxed in with an access door).

I then run SWA from the switched fuse unit outside and then under the floor to the understairs cupboard where I intend to move the consumer unit.

I'd appreciate your thoughts on this.

Many thanks :)


CONSUMER UNIT.png
 
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Since the work is notifiable, you need to decide first if your using a scheme member, or going down the LABC route. And you need to get who ever is signing the paperwork to agree as to where it can go, although at one time under the stairs was common place, today it is not so common and of course there needs to be a route for the cables.

It really does not matter what any one on the forum says, it is down to guy doing the work and if LABC route the LABC inspector.
 
Have you planned how all the other house wiring will be re-routed to the new CU position?
 
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There are maximum lengths for cable runs, the first step is to test the cables to see if they can be extended, a 2.5 mm² ring final has a limit of 106 meters for example, sounds a lot until you realise how cables have to run to comply with rules on drilling beams, so a low ohm ohm meter or a loop impedance meter is required. These tend to be expensive and so not normal to find as DIY tools.

I find the calculations rather complex, so as a result I use a java script program to work it out for me, this shows maximum readings.
volt drop screen shot.jpg

for a ring final, it is the correction factor Ct which is the complex bit, I used Java Script so it would work on my phone, until you have taken the readings and found out if it can be extended or if heavier cable is required etc, it is a non starter. It may be that your well within the limits and you can extend without a problem, but you need to find out before you start, not after completed.

The work is notifiable, and it is very much down to the whim of the LABC inspector, I did a wet room for my mother, and it took some persuading to get the inspector to allow me to DIY, and that is with all the qualifications required to level 5, they wanted me to employ a scheme member to do the work, or at least the inspection and testing, and the problem is the LABC work by the rule book, so not permitted to switch power back on until tested, so you can sit for days without power, clearly you could not live in the house while doing the work.

The main problem is the whim of any inspector, we can tell you what enclosures to use, how to route etc. But if the inspector does not like it, then all to no avail. What I would say is write a detailed application, if you get for example permission to fit an extractor fan at set hight and distance across the wall, then hard for a building inspector to change his mind latter once work started. I had decided not to fit an extractor fan, there were opening windows, then after all the ceiling was in, LABC inspector decided he wanted one. And there is very little you can do.

Work in Liverpool area was easy, the LABC inspectors were very helpful and put in very few demands, Cheshire not quite so easy going, but OK, Flintshire was a real pain, so it does change, so pointless telling you what I found was allowed, it varies from county to county.
 
There are maximum lengths for cable runs, the first step is to test the cables to see if they can be extended, a 2.5 mm² ring final has a limit of 106 meters for example, sounds a lot until you realise how cables have to run to comply with rules on drilling beams
You often say this, but I'd be interested to know how many electricians have actually dealt with a ring final in a 'standard dwelling house' that was anywhere near 106 metres. Even in my (very large, certainly not 'standard') house I don't think that any of my final circuits are anything like like that long.

Kind Regards, John
 
Hands up, yes I have in the past done it wrong, at that time it was 80 meters when we had 4% now we have 5% for most and 3% for lights so it has allowed the 106 meters. But I was lucky I was not caught, I know I did it wrong, but I got away with it.

I am sure there are many times we do it wrong, but get away with it, however where some third party is doing inspection and testing we can't afford to get it wrong.

One job at Jays in Mold I told my boss though cable was too small for volt drop, he told me to carry on, and I latter had to replace it, lucky we were able to hide the error, but it is some thing one learns with time, and I had not calculated volt drop, but guessed it would be on the edge, and most times we have that feeling when cutting it fine and it is more instinct than calculations.

But the DIY man has not done it enough to get the feeling as to when over stepping the mark, and has to rely on calculations.
 
For a standard 2/3 bedroom rewire we used to get sent with 200m 2.5mm² t&e, 200m 1.0mm² t&e, 100m 1.0mm² 3c&e and 50m 10mm² earth and we’d normally have some bits left over at the end.

I’d say the average domestic ring is between 60 to 80m long.
 
For a standard 2/3 bedroom rewire we used to get sent with 200m 2.5mm² t&e, 200m 1.0mm² t&e, 100m 1.0mm² 3c&e and 50m 10mm² earth and we’d normally have some bits left over at the end.
Thanks. I think that's probably roughly as I would have guessed.
I’d say the average domestic ring is between 60 to 80m long.
Again, not a surprise, although I would imagine often much less than that - e.g. with a ground floor (or ground floor kitchen) ring with under-floor (not 'drops from above') wiring.

I certainly can't think of any rings (or radials) in my house that are, per se, particularly long at all - but it's very atypical. Although a very large house, it also has many distributed CUs, so that none of the final circuits are all that long. That obviously means that (both in terms of VD and Zs) the final circuits are not, in themselves, the end of the story, but the distribution circuits are all 16 mm² or 25 mm², and so don't add all that much.

Kind Regards, John
 

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