Information
Definition
Internal PE breakage refers to a charger design where the charger has a means of interrupting or isolating the protective earth path internally as part of its response to a detected PEN fault condition.
Why it matters
This is a sensitive design area. BS 7671 allows PEN fault protection to be integrated into the charge point, while EN 61851 is commonly understood to prohibit interruption of the protective earth conductor within EV charging equipment. Where a charger relies on internal PE interruption, care should be exercised and it may be beneficial to request manufacturer evidence explaining how the PEN protection arrangement, switching components and associated safety functions have been tested and how the design aligns with both installation requirements and product standards.
References
Standards and regulations
BS 7671
BS 7671 is the UK national standard for electrical installations, covering the design, erection, inspection, testing and verification of low-voltage electrical systems. Section 722 contains specific requirements for supplies to electric vehicles.
EN 61851
EN 61851 is the UK-relevant BS EN IEC standard series for conductive EV charging systems, covering EVSE requirements, charging modes, control functions and safety principles for AC and DC charging. In UK terminology it is often referenced through BS EN IEC adoption and manufacturer compliance declarations.
IET 01
IET 01:2024 is a non-statutory IET standard and technical specification for Open combined Protective and Neutral conductor Detection Devices used with EV charging equipment. It sets out definitions, requirements and tests for how discrete or integrated OPDD functions should respond to open PEN conductor faults.