Gas bonding

[Ian1981]

I too was taught this, and had no idea it wasn't the case until I read this thread. Chris Kitcher also teaches it in his book Guide to Inspection, Testing and Certification, even going as far as to give a table of max lengths for different CSA bonding conductors, so easy to see why we're all getting it wrong:
View attachment 54609View attachment 54610

Well bs7671 only gives 2 regulations on sizes, either it is sized to table 54.8 or where non pme conditions apply its to be no less than half the size required of the earthing conductor and not less than 6mm and the key point is that if it’s copper it need never exceed 25mm2.
As protective bonding conductors are not sized to carry fault current then it’s stands to reason that their sizes need only be what is set out in the regulations.
It does seem to be an industry thing this 0.05 figure.