Want new CU fitted, will old circuits require updating?

[joboatbuilder]

Hi, I would really appreciate the advice of more qualified/knowledgeable people than me about how to go about our house's electrical updating- thanks in advance!
We have a c1860s cottage with c1900 and c1960/70 extensions. At present there are two traditional fuseboxes which look like they are from the 60/70s (am assuming that was done when the last extension was built). The first one after the meter is a Wylex box with a single 60A fuse, no other fuseways. from this a cable runs about 4 metres to another main fusebox which houses 4 fuses; Mains, Lights, Cooker, Garage. The mains is one radial circuit for the entire building, (which I am planning on changing to two ring mains at a later date when lifting floors etc for new central heating). All wiring is PVC insulated. I don't know why there are two fuseboxes, unless it was considered necessary to fuse down to 60A from the 100A coming into the house before it went to the next fusebox . All the fuses in both boxes are cartridge wire type ones which I don't like, I'd rather have MCBs.
So what I want to do is have ONE modern split load consumer unit put in AND certified properly by a qualified electrician, making the whole lot modern, safer, giving scope for future circuits, etc. However as he/she would have to connect all the existing circuits to the new CU would the existing radial main circuit have to be replaced to modern standards - ie replaced by 2+ new rings? Do all circuits have to be tested before they are allowed to be connected to a new CU?
My second question is, I have run new 2.5mm2 cable around for a downstairs ring in the living room and dining room and fitted the knockout boxes for sockets. This was so that we could have the walls replastered neatly following damp proofing - I disconnected at the various junction boxes (radial circuit) and removed all the old downstairs single rusty socket boxes as it was pointless having them plastered back in, and didn't want to create work and have to patch the new plaster after chasing the new socket boxes and cables in. No socket faces have been connected, and the tails/ends of the ring are coiled up safely out of the way waiting to be connected to a new CU one day. NO new electrical connections whatsoever have been made, only disconnections of old sockets. Having read numourous posts on the Part P regs, I think I've probably broken the law already as I haven't told the building inspector or my local authority about the new ring that's partly been installed, plus I've done it and I'm not qualified or certified, merely competent to run cables and fit boxes.. But is there any way I would be able to get the wiring runs tested & ok'd and then all the electrical connections made by an electician and therefore certified? Or should I expect any electrician I ask to put in the new CU to rip it out and start again? I'd like to know what to expect before I talk to any electricians.

 

[Steve]

Given the wiringis a good 40 years old, an electrician would want to thoroughly inspect and test every circuit. Every installation is different, so ring mains may not be practical. There are situations where radial circuits are more convenient. There are also situations where more than one consumer unit is considered nessecary, due to RCD requirements. Main bonding may need upgrading, and supplementary bonding in the bathroom.

 

[Dippy]

So what I want to do is have ONE modern split load consumer unit put in

It might be worth considering a single section CU and using RCBOs for circuits requiring residual current protection. That way you don't lost power to multiple circuits when there is a fault trip in only one circuit.

Do all circuits have to be tested before they are allowed to be connected to a new CU?

Yes. I don't think many competent people would do this work without a proper inspection of the existing installation first. Besides, fitting a new CU requires that the whole installation be tested afterwards. It is pointless to fit a new CU, test the installation, find a fault and then have to rectify it, possibly in such a way as to invalidate the CU design.

My second question is, I have run new 2.5mm2 cable around for a downstairs ring in the living room and dining room and fitted the knockout boxes for sockets. This was so that we could have the walls replastered neatly following damp proofing - I disconnected at the various junction boxes (radial circuit) and removed all the old downstairs single rusty socket boxes as it was pointless having them plastered back in, and didn't want to create work and have to patch the new plaster after chasing the new socket boxes and cables in. No socket faces have been connected, and the tails/ends of the ring are coiled up safely out of the way waiting to be connected to a new CU one day. NO new electrical connections whatsoever have been made, only disconnections of old sockets. Having read numourous posts on the Part P regs, I think I've probably broken the law already as I haven't told the building inspector or my local authority about the new ring that's partly been installed, plus I've done it and I'm not qualified or certified, merely competent to run cables and fit boxes.. But is there any way I would be able to get the wiring runs tested & ok'd and then all the electrical connections made by an electician and therefore certified? Or should I expect any electrician I ask to put in the new CU to rip it out and start again? I'd like to know what to expect before I talk to any electricians.

You've done nothing wrong as you haven't connected it. However if this is simply to be an extension of an existing radial then it is not notifiable anyway. However you clearly intend to get someone in to do the work for you so it is academic.

As I understand it, as long as you don't make the installation worse than it is, you are not obliged to bring it up to today's standards. However I doubt that you'll find a professional electrician who will agree to anything more than minor work without doing exactly that.

However sounds like you do want to update the installation, and it would be wise to get a professional to do it. If your wiring is good, then I would expect any reasonable electrician to agree to use it, subject to it passing his inspection and testing.

(P.S. I am not a professional electrician, just a professional electrical engineer).

 

[joboatbuilder]

Thanks very much for your considered replies.

However if this is simply to be an extension of an existing radial then it is not notifiable anyway

So does that mean I am actually 'allowed' to connect the ring I have started to put in to the existing old radial circuit, presumably by simply connecting the two tails to a nearby junction box? I'm not going to, as it seems silly - I could have just replaced what was rusty and affected by the damp work with new cables & sockets but wired up 1960's style

Re the cabling run I've put in - am I not supposed to have informed the local authority beforehand that a new installation is going in? Plus doesn't the electrician have to 'design' the installation, or am I in fact allowed to do that part (but not actually do the installation work!!!! )

Any registered/qualified/certified electricians out there can tell me where I stand, and what you would say if I asked you to come in and carry out the rest of the work?
Thanks for all your help guys

 

[ColJack]

if the cable runs are still exposed then tell the LABC you WILL be doing some electrics in a week or so, then they will send someone round to inspect your cable runs to check you have put them in the safe zones etc BEFORE you can plaster...

if you already plastered, then you'll have to find as registered sparky who won't mind taking responsibility for the work you have done..

if it's only a few hundred mm up the wall, and he can see the cables at the bottom of the wall where they exit the plaster, then he should be able to see they are run in the zones..

 

[Chri5]

I would suggest you bring in the electrician asap and then he will be okay to work with you.

By keeping the cabling dark (unconnected) you haven't gone over the invisible line of them v us. Get a electrician round, explain that it's a stage job and that due to the slow speed of refurbishment and the consideration of other works you would like to segment the work in to stages of:-

cable runs via you
seperate circuit commissioning
certification

It might be best to consider having old and new side by side, then each time you want the additional area added on to the new CU, he comes in has a quick look at the cable routes (which he will want to see), does the socket and switch termination, test and commissioning.

 

[mdbalson]

The Wylex box after the meter is a switchfuse, it may have put in as your DNO does not like the meter tails to be 4m without having aditional overload protection for the long tails from the meter to the fusebox.

 

[joboatbuilder]

What you say about the Wylex box makes perfect sense as the fusebox is at least 4m away.
So it sounds to me that as long as I find a reasonable (certified/qualified) sparky I should be able to run my own cables circuit by circuit, saving the sparky from doing the time consuming messey but (and saving us some money ) and then get him/her to test & connect them all up as and when, and most importantly issue a certificate! Have I got the right idea?