dinbatwrote in an earlier mail:
"547-03-03 - A supplementary bonding conductor connecting two extraneous-conductive-parts shall have a cross sectional area not less than 2.5 sq mm if sheathed or orherwise provided with mechanical protection or 4 sq mm if mechanical protection is not provided..."
6 sq mm does not come into it unless you are complying with 547-03-01 and 02, which deals with the situation where one or both of the extraneous-conductive-parts is an exposed-conductive-part. The requirement here is that the supplementary bonding conductor must be not less than half that of the protective conductor connected to the exposed conductive part/s. Both of these regs also state, "If mechanical protection is not provided, its cross-sectional area shall be not less than 4 sq mm."
And 547-03 is the regulation referred to in 601-01-01, dealing with supplementary bonding in bathrooms.
I still cannot see where the 6mm comes into the equation. For the cable to be 6mm and not less than half the csa of the "protective conductor" then we must be looking at some main bonding. However the main bonding cable would have to be 10mm and the main bond to my consumer unit is 16mm so this would not be adequate.
I can only find info that says that 4mm is the min. for bonding bathrooms without mechanical protection.
I seem to be chasing my tail with this one, so any help would be very much appreciated!
"547-03-03 - A supplementary bonding conductor connecting two extraneous-conductive-parts shall have a cross sectional area not less than 2.5 sq mm if sheathed or orherwise provided with mechanical protection or 4 sq mm if mechanical protection is not provided..."
6 sq mm does not come into it unless you are complying with 547-03-01 and 02, which deals with the situation where one or both of the extraneous-conductive-parts is an exposed-conductive-part. The requirement here is that the supplementary bonding conductor must be not less than half that of the protective conductor connected to the exposed conductive part/s. Both of these regs also state, "If mechanical protection is not provided, its cross-sectional area shall be not less than 4 sq mm."
And 547-03 is the regulation referred to in 601-01-01, dealing with supplementary bonding in bathrooms.
I still cannot see where the 6mm comes into the equation. For the cable to be 6mm and not less than half the csa of the "protective conductor" then we must be looking at some main bonding. However the main bonding cable would have to be 10mm and the main bond to my consumer unit is 16mm so this would not be adequate.
I can only find info that says that 4mm is the min. for bonding bathrooms without mechanical protection.
I seem to be chasing my tail with this one, so any help would be very much appreciated!