Information
Definition
TN-S earthing is an arrangement where the neutral and protective earth conductors remain separate from the supply source to the installation. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.
Why it matters
It affects fault paths, protective device operation and how EV charger earthing is assessed during design. For UK users, it supports safer specification decisions and reduces the risk of misunderstanding how a charger should be protected or installed.
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.