A PEN conductor combines the neutral (N) and protective earth (PE) functions, saving a core in distribution cables, and is earthed at many points along the network. Loss of continuity in it can lift every connected metal case toward line potential, so a PEN conductor must never be switched or fused, has minimum sizes (10 mm2 copper in fixed wiring) and is generally banned inside final circuits.
Lost the PEN on the overhead in the storm and every kitchen tap on the street was giving people a tingle, crew found a burnt joint at the pole.
Also heard as
- combined neutral and earth
- CNE conductor
Related terms
TN-C-S system
Supply earthing in which a combined neutral and earth conductor splits into separate ones at the installation.
TN system
Earthing arrangement where the source is earthed and installation metalwork connects back to it by a protective conductor.
Equipotential bonding
Connecting metal parts together so they sit at one potential and no dangerous voltage appears between them.