Relocating a CU

[Gees]

I am having some work done at home and would like to take advantage of this to have my CU replaced.

The main reason to relocate is cosmetic as it looks ugly sitting on the wall, Also the bathroom work I am having done will be much easier to carry out if the CU is by the meter.
I intend running all ccts from RCD's so will need a new CU anyway.

At present the CU is 15m from the meter where there is a 100 Amp switch to isolate the whole house and the rings and lighting circuits all end up at the "remote" location and will need to be extended.

I do not intend doing this myself but want to prepare as much as possible prior to getting someone in to do the work. The existing CU is at ceiling height in a downstairs room and the concentric mains cable comes in upstairs where the meter is located. this feeds the CU via a very thick cable. I have easy access to the void directly above the CU below the upstairs floor.

Can the cables be extended from their present position with the appropriate junction boxes ( located under the floorboards and easily accessible. ) and end up beside the meter where I would like my new CU to be?

One more thing. can cable be run in trunking up a wall from floor to ceiling or is there a regulation to say it cant be this way. ( trunking will be inside a cupboard )

 

[bongos]

I do not intend doing this myself but want to prepare as much as possible prior to getting someone in to do the work.

Best bet - speak to an electrician before starting any work so they will be happy with the installation, as it is them that has to sign it off. Have a look here.

Can the cables be extended from their present position with the appropriate junction boxes ( located under the floorboards and easily accessible. ) and end up beside the meter where I would like my new CU to be?

Yes but it's not ideal to use junction boxes under the floor as people after you won't know they're there. Best to used crimped connections with heatshrink.

One more thing. can cable be run in trunking up a wall from floor to ceiling or is there a regulation to say it cant be this way. ( trunking will be inside a cupboard )

You can use surface mounted trunking as you want.

 

[Gees]

I did not make myself clear.
I do not intend running cables etc but just to make running the cables very easy. Instead of hours maybe 1/2 an hour. IE just getting the physical stuff done. IE floorboards / trunking etc.

As for not knowing where things are.... I dont know where all the boxes ( if any ) are in my house... How many people DO ?? know this?

 

[ban-all-sheds]

Not many people do, but the problem is that not knowing, or at least them not being accessible for inspection, contravenes the Wiring Regulations.

If you want your CU replaced, and you want it all certified and legal, then you must find your electrician now, and you must discuss with him what work he's happy for you to do. Any other approach won't work.

 

[Gees]

Not many people do, but the problem is that not knowing, or at least them not being accessible for inspection, contravenes the Wiring Regulations.

If you want your CU replaced, and you want it all certified and legal, then you must find your electrician now, and you must discuss with him what work he's happy for you to do. Any other approach won't work.

Thanks for the information.

One thing though. If folk dont know if they have junction boxes in their home how are they supposed to know if they are accessable? This must make most of the homes in the UK illegal

 

[ban-all-sheds]

It's not illegal per se to contravene the Wiring Regulations.

 

[chapeau]

This must make most of the homes in the UK illegal

These regulations are not generally retrospective, so if something was done prior to a new regulation coming in, there is no requirement to bring it up to current standards unless it is found to be unsafe. Only exception off the top of my head to that is connecting metal water/gas pipes to the earth in your house if that was not done in the past.

Whether inaccessible junction boxes are unsafe is hotly contested. The statistics would suggest they are safe, theory would suggest they might possibly cause trouble, but people like to argue for the sake of it and to prove how clever they are.

If you get an electrician in to do this then he will have to sign a piece of paper to say he has followed the regulations, so he is duty bound to follow them, so junction boxes have to be accessible. If you did this yourself then it only has to be 'safe', you would have to get the council in to certify it, and if they accepted that any inaccessible junction boxes were safe then that would be all it needed. Electricians are supposed to follow the current regulations as if they do it removes any reasonable doubt the installation is safe and it is also part of the deal if they want to self certify.

In your example, as bongo has already suggested, to extend your current cables to the new consumer unit, crimping would be the solution of choice anyway.

As for your Consumer Unit, get several quotes as you might be surprised at the price range for what is the same job and you would hate to have got one quote and find that was the most expensive. Ask questions and make sure you get an electician you can work with. It is always sensible to have your wiring tested prior to having a CU changed, some will do that 'free', some won't. Again, get several quotes.

 

[Gees]

I have a leccy coming round this evening !!! to have a look.

 

[bongos]

As for not knowing where things are.... I dont know where all the boxes ( if any ) are in my house... How many people DO ?? know this?

Many people don't - I discovered a mass of junction boxes under my landing. All I was suggesting was that if they can be avoided then all the better (whether upto to exisitng regs or not).

 

[chapeau]

What did you do with them?

 

[ban-all-sheds]

He left the floorboards up.

It's a bit tricky stepping from one joist to another, particularly if you've got up in the night, but at least the JBs are accessible....

 

[sjwkmje]

Personally I do not like any JB's during a CU relocate. I tend to test the ring finals first then the legs to the ring final replace these with new cables, so the rest of the cables if they test ok they can stay and you just replace two legs to each ring final.

Same with lighting I would test and then replace the loop in with new cable.

You also need to look at earthing and any PEBs to gas and water as these should be one continuous length.

The only circuits I tend to extend are cookers, showers if the length cannot be extended but in the location of the old CU I tend to cut into the wall, fit a double metal back box and extend in there with crimps and heat shrink and run a new section back to the new CU location. I use a double so there is some space and fit a blanking plate on top. I have in the past used galv loop in loop out boxes with stuffing glands and done the joints under the floor where I have used crimps but I still prefer them been accessible so try to locate them so they can be got to.

It can take some work to relocate a CU but I have done a few where I have not needed any JB's.

Hope this helps.

Adam

 

[Gees]

Had the guy round earlier on tonight and appart from the cost ( ouch ) the job IS simple.According to him anyway.. He is quite happy for me to prepare the way for cables etc as this will save him a lot of time. The only problem envisaged is the 10mm earth bonding to the gas meter pipe as it involved getting the cable down a lath and plaster wall. I may just take the backmold off a doorframe and he can hide the cable behind that.. other than that its a piece of cake ( we will see !!!! )
Cheers guys. As for hidden junction boxes he reckons if they have been there 20 years they will be ok for a few more.

 

[Gees]

I am still no further foreward here.. I have had a few guys round here to have a look and they all reckon its a simple job. However when they estimate the cost it is simply outragous. One of them said £650 !!!!
and when I asked him for a breakdown of the costs he quoted silly prices like .... £65 for 100 metres of 2.5 twin and earth. Thats twice the price it is to buy. When I said I would supply all the hardware he said he " didnt have the time to do the job " Blooming rip off merchant.
Is this normal practice ( upping the cost of supplies ) or did I just get a bad un?
Another one got all coy when I asked to see his registration paperwork!
And one even admitted he could do the work but would have to get BC to check/test it ( at my expense)
I reckon Stetson hats all round for these particular guys!

 

[1john]

a small mark up on materials is ok i think, as the guy has to go and get them and all that. keep getting quotes as you should have some similar prices and then you can go with the guy that you feel most comfortable in doing the job for you. Make sure you are phoning people registered with a competant persons scheme such as the NICEIC. Good luck.