UK Consumer unit relocation

[Riddler]

Sorry, I know this has probably been covered, but I'm struggling to find a recent and specific answer.

Old 1930's bungalow. Really old CU tucked in the corner of the old converted garage, slightly behind a wall, so barely accessible now. Definitely needs moving, but want to move it toward the main building as we're doing a complete rewire inside.
Don't want to pay the DNO £2.5k they've quoted to move the incoming, so want to move just the board away from the meter and CO fuse.

I've pictured an isolator that our supplier fitted when we moved in.
Now, am I right in thinking this isn't enough to allow me to move the board. I need to add a fused isolator after this one?
Or, is this isolator enough, and I can run separate cables from here, to where I want the new board to be? Or even connect it to an SWA cable to run it round.

I'm pretty sure I know the answer, but the chap that fitted the isolator gave me a different one, so wanted to make sure before I make a horlicks of it and do something stupid

 

[mainline]

How far is the board move ?
Would the run from meter to new Cu be through walls etc ?

If the tails are going to be over 2mtrs (most dnos allow 3mtrs) then the best way is a \MFCU and SWA.

 

[Riddler]

Sorry, completely missed that info off. Yeah it's definitely more than 3mtrs. The board is at the furthest forward point of the old garage/front room, and want it to be closer to the main building. So in a straight line (which would pass outside, it's maybe 4mtrs. But as a cable run, possibly 10, either through the house, or run it back outside and round the building

And what's an MDCU sorry?

 

[Taylortwocities]

but want to move it toward the main building as we're doing a complete rewire inside.

I hope you mean that you have an electrician who will be carrying out the rewire?

Now, am I right in thinking this isn't enough to allow me to move the board. I need to add a fused isolator after this one?
Or, is this isolator enough, and I can run separate cables from here, to where I want the new board to be?

It is ok for the short tails that you have, but a switched fuse is required for the distances you have in mind.

Or even connect it to an SWA cable to run it round.

There's no "or even". If you want to extend the main supply any distance through the house then they must be either RCD-protected at the source (you really dont want to do that) or provided in the correct cable which means SWA. So, SWA is your option, and it will be a chunky one. Your electrician is the person who will need to spec the cable, the fuse size and several other things.

 

[mainline]

Sorry, completely missed that info off. Yeah it's definitely more than 3mtrs. The board is at the furthest forward point of the old garage/front room, and want it to be closer to the main building. So in a straight line (which would pass outside, it's maybe 4mtrs. But as a cable run, possibly 10, either through the house, or run it back outside and round the building

And what's an MDCU sorry?

A mains fused connection unit

 

[James]

There's no "or even". If you want to extend the main supply any distance through the house then they must be either RCD-protected at the source (you really dont want to do that) or provided in the correct cable which means SWA. So, SWA is your option, and it will be a chunky one. Your electrician is the person who will need to spec the cable, the fuse size and several other things.

Earthed Metallic conduit is one other choice.
not normally a preferred one as it is more expensive but it is often an option.

p.s. it may well be 32mm or even 40mm diameter conduit depending on what you are pulling through.

I really think you should discuss in detail with your electrician what the options are and how it will look / what the costs are.

 

[Riddler]

Exactly what I was expecting. The guy who fitted the isolator for the supplier said it was sufficient to now have a long run to a new board, so that threw me. And I know there's a few advocates on here saying it's fine. But better safe etc
Fair to say, we'll have a fused mains switch fitted after that isolator then, and run swa to the where the new board will be

either RCD-protected at the source (you really dont want to do that) or provided in the correct cable which means SWA.

Btw, what's the aversion to using an RCD, like one of the FuseBox mains switches?

Appreciate the info and advice guys

 

[Taylortwocities]

Btw, what's the aversion to using an RCD,

Because it is a single point of failure if you have it at the supply input point. One little earth leakage, on any circuit, and you lose power to EVERYTHING.
SWA does not require RCD-protection.
In your new consumer unit, we hope that you are going for RCBOs on each individual circuit?

 

[mainline]

SWA does not require RCD-protection.

Not strictly true,
It would have to meet the disconnection time.
Do we know what earthing system the o/p has ?

 

[mainline]

Fair to say, we'll have a fused mains switch fitted after that isolator then, and run swa to the where the new board will be

I would install the MFS in place of the isolator that's there.

 

[Riddler]

Not strictly true,
It would have to meet the disconnection time.
Do we know what earthing system the o/p has ?

TN-S

 

[Riddler]

I would install the MFS in place of the isolator that's there.

Is there an issue with fitting it after the isolator? I appreciate it looks odd and untidy, but just means the electrician can do it rather than calling our supplier

 

[mainline]

Is there an issue with fitting it after the isolator? I appreciate it looks odd and untidy, but just means the electrician can do it rather than calling our supplier

Not really an issue but as you said looks untidy and more joints to go wrong.

A lot of electricians call the tooth fairy.

 

[Yellowhammer]

I would hazard a guess your electrician may be able to contact your DNO and have the switch swapped to a MFS very quickly..