An End to Protective Equipotential Bonding?
There are some significant changes being introduced by the 18th Edition of the Wiring Regulations BS 7671:2018.
Chapter 41 has arguably one of the most controversial…
“Metallic pipes entering the building having an insulating section at their point of entry need not be connected to the protective equipotential bonding (411.3.1.2 : BS 7671:2018)”
For example; a ‘plastic’ supply water pipe entering a building goes up to the stop tap where it is then copper pipework throughout the rest of the building. Applying this regulation there is no need to run a protective bonding conductor to this pipework.
I suppose they are saying that due to the plastic section coming into the building that this pipework is not an extraneous-conductive part and as such does not require a protective bonding conductor.
But, wouldn’t whether it was extraneous or not depend on the resistance of the pipework to earth?
Again for example; let’s suppose that the non-bonded internal copper pipework comes into contact with a section of structural steelwork. Wouldn’t the copper pipework then become an extraneous-conductive part?
More to follow…