Meter Moving Away From Consumer Unit

[Evans Electric]

Hi Runner and all those willing to comment and advise. 

Though I'm gradually gaining experience having completed a number of installations, I've often found info on this forum useful but until now haven't needed to ask for specific advice.

Along with a full re-wire, a customer wants their C.U. moving to a point under the hall stairs ( approx 10 meters from meter)

I appreciate that the first thing required will be a fused switch e.g. (excel 80a fused double pole main switch) placed close to the meter.  (Though wouldn't this 80a fused switch make the 100amp switch in the C.U. irrelevant? can you get a 100amp fused main switch?)

My main question though is, is there a preferred option for running from the fused switch to the C.U.?

(Bulk of the run will be visible in the cellar with approx 1.5 meters needing to hide / be buried as it comes up the hallway wall to the C.U.

Would you advise 25mm SWA ? or 25mm tails (16mm earth) with some steel plate (earthed) protection as they become concealed? or any other options??

 
The house is a fair size ( 4 Bed ) with  TN-S earthing.The current installation already has a similar set-up with an old fused switch next to Meter & 16mm tails run approx 15 meters to the old fuse board in the kitchen. However this was possibly done by the old fella that used to live there, and anyway the regs have moved on since this was installed.

I appreciate all advice and comments.

Thanks Switch Snow

The 100A switch in the C/U  is the local isolator ..the 80A sw/fuse is fusing & isolating the sub-main .

The 17th edition has blessed us with the " Cables buried flush in the walls"   business which can cause consternation with sub-mains as no one wants an overall RCD if they can help it. 

Lets have a look at the options open to us , some are bordering on madness but things change and we have to go with it .

So depending upon methods of installation .:-

1)  16mm T/E    could go with a 63A fuse or an 80A depending on method .

2)  16mm   SWA  2 or 3 core  ...armour earthed at mains end /flush in wall/ no gland at C/U .

3)   16mm X 3 core Non-Armoured  Ins/shd run surface , if flush would need an earthed plate over it  or steel conduit 

4)   16mm  Meter tails @ 63A  or clipped direct @ 80A    (the flush business applies the same)

5)   25mm Tails @ 100A   clipped direct. / boxed in / trunking  etc.

6)   Run cable surface outside and straight into  back of board.

7)   Edit :-   Forgot Pyro   Probably 10mm without looking .

The average 3 bed semi will usually function with a 60A  HRC fuse quite happily. 

Is there a ruling in the Regs on the size of a steel plate for covering sub-mains ?    I don't know ...would some 2mm thick seel plate suffice ..who knows ?

 

[Sidewinder]

IIRC, it's 3mm steel plate that is deemed to be the minimum for earthed protective "capping" materials.

 

[Evans Electric]

As always ...thanks again for that heads up Sidey,  I thought I'd  seen reference to it . 

 

[Sharpend]

Concur with the snake !

 

[sprocketflup]

Just as an aside, im doing a rewire at the moment where the meter head is in a wide but not very tall cupboard in the kitchen. Along with this there is also an Off peak meter and switchover timeclock, and two old wylex rewireable boards.

The meters and head are smack bang in the middle, with a wylex board either side. Unfortunately for me, there isn't enough room on either side for my new CU.

The customer/new home owner doesn't want off peak, so removal of the off peak board, meter and timeclock will give me enough space for a decent sized CU.

Im assuming I cant just remove the off peak set up myself, as it belongs to DNO, but does anyone know how much they'll charge to remove it? Its Western Power

 

[Sidewinder]

sproc,

My crystal ball is goosed mate, you'll have to ask WPD, however, they no longer supply electricity for sale, they merely operate the infrastructure.

They are "only" a DNO.

So it could end up being down to the electricity provider in the property.

This is one of those stupid areas thrown up by the fragmentation of the metering/supply etc.

 

[sprocketflup]

sproc,

My crystal ball is goosed mate, you'll have to ask WPD, however, they no longer supply electricity for sale, they merely operate the infrastructure.

They are "only" a DNO.

So it could end up being down to the electricity provider in the property.

This is one of those stupid areas thrown up by the fragmentation of the metering/supply etc.

yeah that's kind of where Im coming from, the DNO is WPD but their 'supplier' is Ovo Energy, whoever the **** that is

 

[Sidewinder]

TBH, I would start with WPD and see what they say.

The call centre is as good a place as any.

 

[Evans Electric]

Just as an aside, im doing a rewire at the moment where the meter head is in a wide but not very tall cupboard in the kitchen. Along with this there is also an Off peak meter and switchover timeclock, and two old wylex rewireable boards.

The meters and head are smack bang in the middle, with a wylex board either side. Unfortunately for me, there isn't enough room on either side for my new CU.

The customer/new home owner doesn't want off peak, so removal of the off peak board, meter and timeclock will give me enough space for a decent sized CU.

Im assuming I cant just remove the off peak set up myself, as it belongs to DNO, but does anyone know how much they'll charge to remove it? Its Western Power

I've done this on numerous occassions Sprocket,  usually when the customer cannot get any sense from their power supplier.   Customer then phones to say they no longer have unused Off Peak metering .

Last time we did it at a Vet's  .  He asked supplier to remove unwanted off peaks  plus other stuff ...they said you have to get your contractor to do it ....so he did ! 

 

[OnOff]

IIRC, it's 3mm steel plate that is deemed to be the minimum for earthed protective "capping" materials.

Does / should that logic not extend then to steel conduit? I've just measured a offcut of 20mm galv in the bag and it comes up 20mm with a 16.5mm internal diameter........so a wall thickness of 1.75mm. Don't know the make (would have to dive to the garage and look at a full length) but came from WF. 

And top hat capping is nowhere near 3mm thick........

 

[Sidewinder]

Conduit is fine as it has a product standard.

Capping is not classed as suitable mechanical protection.