TN-C-S

Protective Multiple Earthing (PME)

The most common modern UK supply arrangement: the distributor combines neutral and earth in a single conductor (the PEN) up to the service head, where it splits into separate neutral and earth for the installation. Its weakness is a broken PEN conductor, which can put the whole installation's earthed metalwork at a dangerous voltage — the reason special rules apply to EV charging and other outdoor equipment on PME supplies.

Taught and practised in the Installation section.