Meter Moving Away From Consumer Unit

[runner]

HI all,

after spending the afternoon reading threads on this site I just wanted to confirm what to do.

A customer is having there incoming supply fuse and meter moved to the front of there bungalow via one of those white boxes set into the wall.

I need to get power back to their consumer unit in the hallway approx. 4 meters away and up above their door.(total approx. 7 meters)

As I understand it I would need to put a MEM 80A fused switch alongside the meter in the white box to protect the cable to the fuseboard, then

I could drop down under the floor to the hallway and then I need to get up the wall. The customer wants the cabling concealed so can I use 16mm

twin and earth from the switch upto the wall and then run it in 32mm steel conduit in the wall along with a separate 10mm earth cable. The bungalow

only has 12 sockets plus kitchen electrics and no electric shower.

The other suggestion appears to be a 25mm SWA cable.

Your thoughts would be appreciated.

thanks

Runner

 

[NozSpark]

Earthed steel conduit, SWA or surface are the only options IMHO,,,, however why would you use 25mm SWA when you would use 16mm T&E????

 

[batty]

Twin & earth is OK as long as the conduit is earthed. It is also easier to work with. Trying to terminate SWA in meter box is never easy and if Switch fuse is to large DNO may say they cannot connect supply. You could probably get away with 16mm SWA on a 80 amp supply.

 

[runner]

Thanks guy, just wanted confirmation.

Nozspark, lots of people keep on about 25mm swa as the armoured cable alternative, I guess they may have been considering heavy ish loading ?

Just need to see if a 16mm t&e and a 10mm earth will fit in a 32mm steel conduit

batty, I agree with the easier to work with when space is an issue.

thankyou both

cheers

 

[Evans Electric]

32mm steel conduit in a house , flush!! .....  cripes,,,   hope the wall isn't just a 4" 

Amazing isn't it ............ if it were pipes going up there , they'd be boxed in and nothing said.

Got to be honest , if I was doing it it would be plastic trunking I'm afraid.

 

[Evans Electric]

Probably demolish the wall chasing that in .

 

[batty]

I would rather put steel plate that is earthed over the tails have done that a few times.

 

[m4tty]

Think I'd just use swa and cut out all the messing with steel etc be a lot easier

 

[Steve3948]

I don't think it's got to be steel plate, just earthed cover, so triple metal capping ??

 

[runner]

Thanks for the comments, a buddy can get me some lengths of steel plate so probably going to do it that way.

Just out of curiosity, why does the cover need to be earthed ?  I assume the earthing is going to the fuseboard and would trip an RCD but

the tails would still be live as they are on the incoming side of the fuseboard and protected by an 80amp switch.

 

[steptoe]

the tails should be protected by a fuse,

use an 80amp switch fuse at the meter for the tails.

 

[Jono Pashley]

Thanks for the comments, a buddy can get me some lengths of steel plate so probably going to do it that way.

Just out of curiosity, why does the cover need to be earthed ?  I assume the earthing is going to the fuseboard and would trip an RCD but

the tails would still be live as they are on the incoming side of the fuseboard and protected by an 80amp switch.

The same reason you would earth steel conduit/trunking/tray/swa

 

[runner]

Steptoe I was going to use a MEM 80amp fused switch in the white box next to the meter.

Jono, I was thinking - when you earth steel conduit/ trunking/ tray / swa etc  it's covered by an rcd so if it was to become live somehow the rcd trips

and problem solved but if the conductors within it are not protected by an rcd then couldn't the metal covering in theory become live but I guess the

main fuse would blow instead

thanks all

 

[NozSpark]

I'm really not being funny here, but from your above replies #11 & #14 you don't seem to understand how the protective devices will work in the given scenario.

Are you sure that you're up to this job?

 

[Steve3948]

+1 to that.

 

[runner]

Sorry just reread my posts, your right, I'm not thinking straight, just finished a 13hr day and brains not functioning,

I do appreciate everyone's comments.

Cheers

 

[batty]

Has DNO provided you with an earth?

 

[runner]

The job isn't being done for a few weeks, installation currently is TNCS and I assume they will just terminate the incoming supply back towards where it enters the property and

it will be the same earthing arrangement.

 

[Switch Snow]

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

 

[steptoe]

first thoughts would be 25mm SWA

have you worked out the actual loading? my house runs off a B63 quite happily,