New supply to new build

[davesparks]

Mate the time delayed rcd back in garage will cover the cable ,and yea guys i have a rethink bout cable size and do maths again just in case ,

Why do you need the time delayed RCD?
It won't protect the cable for OL or SC fault

 

[steviethespark]

Why do you need the time delayed RCD?
It won't protect the cable for OL or SC fault

So that if the 30ma trips in the house trip it wont trip out in garage all the time

 

[davesparks]

So that if the 30ma trips in the house trip it wont trip out in garage all the time

I mean why does the sub main require an RCD?

 

[telectrix]

I mean why does the sub main require an RCD?

it shouldn't if it's installed properly.

 

[steviethespark]

I was covering the sub mains because the cable will be live from a very early stage and there will be quite a bit of digging around it for sewers ect at a later date

 

[Leesparkykent]

I was covering the sub mains because the cable will be live from a very early stage and there will be quite a bit of digging around it for sewers ect at a later date

smacks of bad design though to have an upfront RCD don't you think?

 

[steviethespark]

smacks of bad design though to have an upfront RCD don't you think?

No i dont think ,can u explain

 

[davesparks]

I was covering the sub mains because the cable will be live from a very early stage and there will be quite a bit of digging around it for sewers ect at a later date

It's a few years since I last worked on a new build house, but when I did they always completed that kind of ground works a lot earlier in the job than the point when we started livening up the circuits. We only had the temp supply board live at that time.

And if it's being buried then split con doesn't comply as it doesn't have a complete earthed metallic layer,

 

[davesparks]

No i dont think ,can u explain

Leaving the whole installation with overall RCD protection for no other reason than poor coordination and project planning during the construction stage is not good installation design.

 

[steviethespark]

It's a few years since I last worked on a new build house, but when I did they always completed that kind of ground works a lot earlier in the job than the point when we started livening up the circuits. We only had the temp supply board live at that time.

And if it's being buried then split con doesn't comply as it doesn't have a complete earthed metallic layer,

U might want to check that because split does comply

 

[davesparks]

U might want to check that because split does comply

Split concentric does not, a buried cable should have an earthed metallic sheath or armour. Split con does not as over 50% of the outer layer is neutral, not earth

 

[Leesparkykent]

U might want to check that because split does comply

check what? you want to feed a new board with a cable that has an RCD at the front of it...........

edit: just realised the quoted is on about split concentric cable lol

 

[HandySparks]

Split concentric does not, a buried cable should have an earthed metallic sheath or armour. Split con does not as over 50% of the outer layer is neutral, not earth

The OP says it's in 4" soil pipe, not buried direct.

 

[HandySparks]

It won't protect the cable for OL or SC fault

Indeed, hence my question. No answer on that one yet.

 

[davesparks]

The OP says it's in 4" soil pipe, not buried direct.

But still underground and needing an earthed armour or similar