5.7.1 - What is earthed concentric wiring?
This is the TN-C system {5.2.5}
where a combined neutral and earth (PEN) conductor is used
throughout the installation as well as for the supply. The
PEN conductor is the sheath of a cable and therefore is
concentric with (totally surrounds) the phase conductor(s).
The system is unusual, but where employed almost invariably
uses mineral insulated cable, the metallic copper sheath
being the combined neutral and earth conductor.
|