Hi, Please help............
Up until now I have been lucky enough to install CU's almost directly side by side to the main incoming supply/meter. I have just been asked to wire a new build from scratch and my lack of experience in this situation has raised a question...
The plans show the Consumer unit positioned approximately 10 meters away from the meterbox. (The main incoming TNC-S supply and meter box is on the outside front wall of the building and the CU is proposed to go under the stairs).
I have always worked on the rule that if the meter tails are no longer than 3 meters and clipped direct to a surface wall then there is no need for any additional protection or a 100amp main switch between the two, but this job does not fall in this category.
My questions are how would you best advise me to run the meter tails from the meter to the CU?
Do I need to fit a 100amp DP main switch next to the meter?
Is the 100amp DP main switch fitted for maintenance purpose or does it hold any other values? (ie a better choice rather than henleys.)
Do I need to fit the 100 amp DP switch between the meter and CU at all?
What would you advise is the best way to run the supply tails to the CU?
Should I run the supply tails through the cavity of the wall because there will be no RCD protection, and therefore they are buried more than 50mm? If so where should they run internally of the installation (ie when they pass behind the plaster board)? If I am to run them through a partition (buried less than 50mm) then from my understanding they will either need to be RCD protected (which would cause a discrimination issue between an RCD main switch at the origin and at the CU) or mechanically protected eg 25mm SWA (which I have never come across and seems over the top) to comply with 17th edition.
Sorry to sound incompetent, but I have checked the regs and can't find an answer. This is my 1st new build so im unsure. It is an install that I am not familiar with and would rather ask the question now and avoid problems in the future.
Your advice would be very much appreciated...................
Up until now I have been lucky enough to install CU's almost directly side by side to the main incoming supply/meter. I have just been asked to wire a new build from scratch and my lack of experience in this situation has raised a question...
The plans show the Consumer unit positioned approximately 10 meters away from the meterbox. (The main incoming TNC-S supply and meter box is on the outside front wall of the building and the CU is proposed to go under the stairs).
I have always worked on the rule that if the meter tails are no longer than 3 meters and clipped direct to a surface wall then there is no need for any additional protection or a 100amp main switch between the two, but this job does not fall in this category.
My questions are how would you best advise me to run the meter tails from the meter to the CU?
Do I need to fit a 100amp DP main switch next to the meter?
Is the 100amp DP main switch fitted for maintenance purpose or does it hold any other values? (ie a better choice rather than henleys.)
Do I need to fit the 100 amp DP switch between the meter and CU at all?
What would you advise is the best way to run the supply tails to the CU?
Should I run the supply tails through the cavity of the wall because there will be no RCD protection, and therefore they are buried more than 50mm? If so where should they run internally of the installation (ie when they pass behind the plaster board)? If I am to run them through a partition (buried less than 50mm) then from my understanding they will either need to be RCD protected (which would cause a discrimination issue between an RCD main switch at the origin and at the CU) or mechanically protected eg 25mm SWA (which I have never come across and seems over the top) to comply with 17th edition.
Sorry to sound incompetent, but I have checked the regs and can't find an answer. This is my 1st new build so im unsure. It is an install that I am not familiar with and would rather ask the question now and avoid problems in the future.
Your advice would be very much appreciated...................