Cable type to use

Hi,

A relatively minor issue but your thoughts will be appreciated.

An existing domestic installation is to have the internal service head moved to a new external meter box. A new 10m long 80-100A 1ph distribution cct will therefore be run from a switch fuse in the meter box (contentious, perhaps) to the CU.

The meter box will be approx 2-3 feet off the ground. The proposed cable route is to drill through the wall below the meter box up to approx a foot of the ground, that will go through into the basement.

The distr cct will be in the order of a 25mm2 cable. The issue is then the type of cable to use?

- A 3 core SWA will be difficult to use because its bending radius will be too great to get into the meter box; and drilling downwards to lessen the angle is inadvisable given water could track down the cable into the basement even after packing with sealant but which may deteriorate.

- Tails could be used, that are mechanically protected in e.g. conduit emanating from an adaptable box.

- Of interest though (due to not having used it before) is thoughts on using split-concentric in this scenario (which table F5 of GN 1 lists for general use) - given the short distance between the hole and the bottom of the box, perhaps it will be easier to bend up into box.

So thoughts please on using split-concentric.

Thanks.

Parents
  • Looking at Cleveland splitcon 25mm is 18.3mm diameter. Minimum bending radius is 6x18.3°=109.8 so it sticks out from the wall by 109.8+18.3=128.1mm, which is quite a chunk.

    Drilling diagonally allows a small portion of the cable to be buried within 50mm of the surface, on both sides of the wall.

    Clipping to the basement joists might be method C now, but will it be method B after it is plasterboarded?

Reply
  • Looking at Cleveland splitcon 25mm is 18.3mm diameter. Minimum bending radius is 6x18.3°=109.8 so it sticks out from the wall by 109.8+18.3=128.1mm, which is quite a chunk.

    Drilling diagonally allows a small portion of the cable to be buried within 50mm of the surface, on both sides of the wall.

    Clipping to the basement joists might be method C now, but will it be method B after it is plasterboarded?

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