Technical Specification – Compliance
TechProServ™ initially undertook a survey to define the metering and adequacy of supply, earthing arrangements and simultaneous contact assessment.
We completed a risk assessment on the building for its potential Installation of a vehicle charging application, this specifically identifies and evaluates the PME supply and vehicle charging equipment to be installed indoor or outdoor and if a potential TT System (earthing arrangement) is required for the charging equipment only. In the event of an open-circuit neutral in the PME supply system (T-C-NS), all conductive parts connected to the main PME earthing terminal, e.g. any exposed or extraneous conductive parts that maybe directly, or indirectly, or otherwise connected to this earthing terminal, may become raised to a dangerous voltage relative to true earth.
TechProServ™ assessed the current demand of the existing installation and verified compliance for the new load.
Design and implementation – Electrical and Physical installation requirements
Our design reviewed and defined compliant locations, impact protection, ventilation, trip/fall hazards and obstructions. We confirmed conformity to BS EN 61851 Electric Vehicle Conductive Charging System, BS 7671 Requirements for Electrical Installations, including particular requirements in section 722: Electric Vehicle Charging Installations.
We reviewed the manufacturer’s instruction for the intended design, and its implication of the installation, following these requirements to ensure the equipment works as intended and meets the regulations.
The charging equipment at City Hub is located indoors with a tethered non-extending cable that only allows the vehicle to be charged inside, then the PME earth (T-N-CS) can be used without the need for a separate TT earthing arrangement and/or PEN monitoring. If the vehicle was to be charged outside, then a separate TT system and/or PEN monitoring should be adopted as well as other measures.
The Risk Assessment shows that it is not currently necessary to take any precautions to avoid an open-circuit neutral fault as the charging equipment is within the same equipotential zone which is permitted to use the current T-N-CS earthing.