J
John1981
Hi.
We're currently carrying out an installation in a large steel framed building on an agricultural property.
Supply in, is TNS. Supply intake is approx 225m from the new building. We require an 80a 3 phase supply, which has been sized at a 95mm SWA with a 25mm CPC. 300ma TD RCD on main board in new build. Due to it's steel frame nature we're intending to bond the S/Steel work, but we've now just found out there's going to be steel Biomass pipes entering the building from underground. I know on a TNS supply, maximum equipotential bonding CSA is 25mm. Anyone any idea on how to treat this whole earthing situation before i drive into the regs. Are we to bond the extraneous conductive parts with a separate bonding conductor back to the MET? Technically the building itself is an earth electrode. My concern is of that the earthing and bonding conductors via the SWA and 25mm will be undersized? Any opinions would be greatly appreciated.
We're currently carrying out an installation in a large steel framed building on an agricultural property.
Supply in, is TNS. Supply intake is approx 225m from the new building. We require an 80a 3 phase supply, which has been sized at a 95mm SWA with a 25mm CPC. 300ma TD RCD on main board in new build. Due to it's steel frame nature we're intending to bond the S/Steel work, but we've now just found out there's going to be steel Biomass pipes entering the building from underground. I know on a TNS supply, maximum equipotential bonding CSA is 25mm. Anyone any idea on how to treat this whole earthing situation before i drive into the regs. Are we to bond the extraneous conductive parts with a separate bonding conductor back to the MET? Technically the building itself is an earth electrode. My concern is of that the earthing and bonding conductors via the SWA and 25mm will be undersized? Any opinions would be greatly appreciated.
