temporary supply

[1Justin]

I'm arranging to quote for a new build (my first new build). Ultimately will be PME. On plans, the supply head is to be rising in the centre of the property within a plant room.

How/where might you arrange the temporary (TT) supply for the site, when the slab and all the groundworks would be going on all around the final location of the head?

 

[telectrix]

right by the head. mind the incoming cable. 2 screwed rods coupled together and a 30mA RCD covering the wole themporary installation.

 

[Octopus]

I'm arranging to quote for a new build (my first new build). Ultimately will be PME. On plans, the supply head is to be rising in the centre of the property within a plant room.

How/where might you arrange the temporary (TT) supply for the site, when the slab and all the groundworks would be going on all around the final location of the head?

Where will the meter be?

 

[1Justin]

.. Thanks, yes ..but "right by the head" is in the middle of the slab (probably yet to be cast when the site supply needed in the first place).

 

[Bobster]

Concrete foundations with rebar inside?

 

[1Justin]

Hi Murdoch.
The meter will be as far as I can tell from plans, at the head which the centre of the slab. I guess you are saying if there were an external plastic box with tails as normal, that would (I agree) be the ideal place. The customer doesn't want any external plastic boxes on the wall, and as far as I can tell, the meter would be at the head.

 

[1Justin]

Concrete foundations with rebar inside?

I think so, yes. It's a passivhaus so there may be an unconventional/thick insulation/massive slab, but it could well be a raft with rebar.

 

[Octopus]

Hi Murdoch.
The meter will be as far as I can tell from plans, at the head which the centre of the slab. I guess you are saying if there were an external plastic box with tails as normal, that would (I agree) be the ideal place. The customer doesn't want any external plastic boxes on the wall, and as far as I can tell, the meter would be at the head.

I don't think thats a decision he can make. As far as I can remember the meter will need to be on an accessible wall on the outside of the building.

I think your customer needs to check with the supplier

 

[davesparks]

As rob has suggested above, if you are going in before the concrete is poured then it's the perfect opportunity to get an earth onto the reinforcing mesh.
That should give you a lovely earth connection once the concrete is in which can stay in place for the finished job.

 

[1Justin]

Thanks Murdoch. I'll check upon that, and if so, it would, of course also answer the question

 

[1Justin]

As rob has suggested above, if you are going in before the concrete is poured then it's the perfect opportunity to get an earth onto the reinforcing mesh.
That should give you a lovely earth connection once the concrete is in which can stay in place for the finished job.

That would rely on the rebar in the mesh being "concreted" to the sub soil. - It may be quite isolated in this case if there were a thick slab of foam under.
More homework needed.

 

[Bobster]

I think so, yes. It's a passivhaus so there may be an unconventional/thick insulation/massive slab, but it could well be a raft with rebar.

Then look up Ufer Earthing, will provide an really low Ra, and can be left in place to supplement the PME

 

[Octopus]

Thanks Murdoch. I'll check upon that, and if so, it would, of course also answer the question

No problem mate, nice question, good prompt responses,

I do WISH others could have the same approach!

 

[Engineer54]

1 ..... Use the concrete slab as your temporary TT Earth electrode (eg, the miles of rebar that will embeded in the slab) and later use the same connection to the PME supplies MET!!

EDIT.....Looks like i took too long to type and post ...lol!!


2 .... I'd strongly suggest you get a duct or two laid from the direction of the DNO supply to the service cut-out/meter position. I wouldn't be direct burying unless you go ''Deep''!! lol!!

 

[1Justin]

Thanks guys. I just spoke to DNO.
They say their procedure would be (on application).. Shorten existing supply (prior to demolition) to temporary location outside the property.
Cast-in a duct to the new head location (DNO has spec for the duct). After the build, the new supply is shoved up through the duct and old temp supply disconnected.
QED (it seems).