Industry jargon
Open PEN fault
Also called broken PEN conductor · open PEN conductor
An open PEN fault is a break or loss of continuity in the combined protective earth and neutral conductor used on a TN-C-S distribution network.
In this condition, conductive parts connected to the installation's protective conductors can rise to a dangerous voltage relative to the ground. The risk is important for EV charging because a person can be standing on the ground while touching the vehicle body.
UK charging-installation requirements therefore include protective measures for situations where a PME earthing facility is used. An Open PEN Detection Device is one recognised way of detecting symptoms of this distribution-network fault and disconnecting the vehicle in accordance with its specification.
Read more Standards, Safety & Compliance