Terms in Power Supply Topology category referencing BS 7671
Standard or regulation
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.
A
Active Load Management (ALM)
Active Load Management (ALM) is a load control approach that monitors available electrical capacity and actively adjusts EV charging demand in response to changing site conditions. It may use live measurements, control rules or backend commands to reduce, increase or redistribute charger output.
C
Configurable Current
Configurable current allows the maximum charging current to be set or limited during installation or configuration. It is normally assessed against site capacity, maximum demand, charger grouping and the behaviour expected when electrical demand changes.
E
Earth Electrode
An earth electrode is a conductive part placed in the ground to provide an electrical connection to earth. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.
I
Individual Supply Per Outlet
Individual supply per outlet means each charging outlet has its own dedicated electrical supply or separately protected feed. It is normally assessed alongside phase availability, circuit capacity, protective devices, cable sizing and DNO/site constraints.
Internal PE Breakage
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.
IT Earthing
IT earthing is an arrangement where the supply has no direct connection to earth or is connected through a high impedance. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.
O
Overcurrent Protection Rating
Overcurrent protection rating is the current value assigned to a protective device, normally stated in amps. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.
P
PEN-Fault Protection (PEN)
PEN-fault protection is protection against hazards caused by a broken or open combined protective and neutral conductor in PME/TN-C-S supplies. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.
PME Earthing
PME earthing is an earthing arrangement where the supply uses Protective Multiple Earthing with a combined neutral and protective function upstream. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.
PME Protection
PME protection refers to protective measures used to address risks associated with Protective Multiple Earthing supplies, especially open PEN faults. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.
Power Daisy Chaining
Power daisy chaining uses a supply arrangement where power is routed from one charger or connection point to another in a chained layout. It is normally assessed alongside phase availability, circuit capacity, protective devices, cable sizing and DNO/site constraints.
Power Supply
Power supply refers to the electrical supply arrangement feeding a charger or group of chargers. It is normally assessed alongside phase availability, circuit capacity, protective devices, cable sizing and DNO/site constraints.
R
Rated Current
Rated current is the maximum current a charger or electrical component is designed to carry under specified conditions. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.
S
Single-Phase Charging
Single-phase charging uses a single-phase AC supply, commonly found in many UK domestic and small commercial installations. It is normally assessed alongside phase availability, circuit capacity, protective devices, cable sizing and DNO/site constraints.
T
Three-Phase Charging
Three-phase charging uses a three-phase AC supply and can support higher AC charging rates where the vehicle and charger are compatible. It is normally assessed alongside phase availability, circuit capacity, protective devices, cable sizing and DNO/site constraints.
TN-C-S Earthing
TN-C-S earthing is an arrangement where neutral and protective functions are combined in part of the supply and separated within the installation. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.
TN-S Earthing
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.
TT Earthing
TT earthing is an arrangement where the installation uses its own earth electrode rather than relying on the distributor's protective conductor. It is normally assessed during product selection, circuit design, installation verification and maintenance of EV charging equipment.