Careful_Bodger said:
I was also confused since SS uses 'Supplementary Equipotential Bonding', whereas the IEE shorten it to 'Supplementary Bonding'.
Careful, one of the first things I said was that the phrases "Main Bonding" and "Supplementary Bonding" should have the word "Equipotential" inserted in the middle.
Therefore, the phrase 'Supplementary Bonding' is a legitimate replacement for 'Supplementary Equipotential Bonding'.
Both the IEE and the NIC recognise this.
The IEE's definition of extraneous conductive part is: A conductive part liable to introduce a potential, generally earth potential, and not forming part of the electrical installation.
So, taps and pipes come under this description.
Where have you found the definitions?
You also say that "The IEE's definition puts this into the Supplementary Bonding category."
So why do I see in the regs, a diagram showing a main equipotential bonding conductor feeding a main water pipe and an extraneous conductive part?
Furthermore, regulation 413-02-02 states that main equipotential bonding conductors shall connect to the MET extraneous conductive parts including:
water service pipes, gas installation pipes, other service pipes and ducting, central heating and air-con systems, exposed metallic structural parts of the building, and the lightning protective system.
NOT just "services such as water and gas".
Have a look at a copy of the OSG (On-site Guide). This should help.