An extraneous conductive part is a conductive part liable to introduce a potential, generally earth potential, and not forming part of the electrical installation.
According to the IET it should be noted that the term extraneous-conductive-part is hyphenated, which means it is a single term which has a specific meaning. It can sometimes be difficult to determine if a part meets this requirement, therefore it is sometimes easier to break the definition down into three separate parts.
- A conductive part
- Liable to introduce potential, generally earth potential, and
- Not forming part of the electrical installation.
The statement “Liable to introduce potential, generally Earth potential” is where it can sometimes be difficult to assess by visual inspection alone. Earth potential is generally assumed to be 0 volts introduced by the general mass of Earth more commonly known as the planet we stand on.