Fitting electric vehicle (EV) chargers – What installers need to know

Offering a clean, low carbon alternative to petrol and diesel models, electric vehicles (EV) are an increasingly common sight. With growing demand for domestic charging points, Rob Shepherd takes to the road to find out more about the opportunities for electrical contractors in this area and what to consider when installing them.

Figures from the Society of Motor Manufacturers and Traders (SMMT) show that Britain’s millionth EV hit the road in January 2024. Given that registrations of EVs numbered just 3,500 in 2013, it shows just how far this sector has come in a relatively short time. This bodes well for electrical contractors, who stand to benefit from the installation of domestic charging points that will be necessary to make the successful transition to electric motoring.

Opportunity knocks

Most EVs have a range of 100-200 miles before their batteries run flat, while some top end cars can run for over 300 miles. This doesn’t sound much but is adequate for most journeys. Although an accessible public charging point network is vital, the Energy Saving Trust estimates that 80 per cent of EV charging takes place at home due to its affordability, convenience and safety.

It’s tempting to think that having a dedicated charging station at home is unnecessary, as a standard domestic three-pin socket can be used. While this suitable for overnight charging during visits to friends or relatives, it’s not recommended for regular use at home. Using a standard domestic socket for charging an EV can lead to slower charging speeds and may not provide the necessary safety features and reliability compared to a dedicated EV charging point. Regular use of a standard plug for EV charging can also put additional strain on household wiring and increase the risk of overheating or electrical faults.

There are numerous opportunities for electrical contractors in the installation and maintenance of domestic charging points, as many large EV charging companies are concentrating on commercial and public sector projects. Before taking the plunge though, contractors need to familiarise themselves with the growing range of charging technology that is currently available.

Need for speed

Charging technologies can be classified into three key groups – slow, fast and rapid. Slow charging units, typically up to 3kW, are suited for a 6-12 hour overnight charge, 7-22kW fast chargers can complete a charge in 3-4 hours, while 43-50kW rapid charging units are able to provide an 80 per cent charge in around 30 minutes.

Then there’s the decision to be made about whether to use a tethered (attached cable) or untethered (unattached cable) charge point. This ultimately boils down to personal preference, but there are important factors to consider. Opting for a tethered charger means a cable for a Type 1/Type 2 socket is readily available, however, there are drawbacks to consider. With a tethered charger, you might face the risk of your home charge point becoming obsolete if the industry shifts away from Type 1/Type 2 sockets in the future.

Under the Electric Vehicles (Smart Charge Points) Regulations 2021, every EV charger is required to be equipped with smart technology. This allows charging during periods of lower grid demand or when more renewable energy is accessible. Additionally, charge points must adhere to specific device-level standards, ensuring consumers have access to a minimum level of security, information and functionality. For an EV charger installation, a Wi-Fi connection or a dependable 4G network is essential to enable the charger to link up with a central server, facilitating functions like receiving instructions, regulating the charging rate and logging energy consumption.

Just a phase

It is vital to carry out a comprehensive evaluation a home’s electrical set-up to assess its capacity and suitability for an installation. This will verify that the charger is linked to a dedicated circuit with the correct voltage and amperage ratings – a critical step for ensuring the safe and effective functioning of the EV charger. A fundamental aspect of EV charger installation involves confirming that a home’s electrical infrastructure can manage the added load – typically, Level 2 chargers operating at 230V demand a dedicated circuit with a minimum of 40A.

In the UK, single-phase electricity supply is the standard for residential properties, offering up to 7.4kW for EV charging. If a faster charger is required, contacting the distribution network operator (DNO) for a fuse upgrade is necessary, which can be a lengthy process. Properties equipped with three-phase power are typically larger and while three-phase charging is faster than single-phase, upgrading to this system is costly and time-consuming.

Rules and regulations

Installing a domestic EV charger involves adhering to specific wiring regulations to ensure safety and compliance, and ensure proper electrical connections, cable routing and circuit protection. Any EV charger installation must adhere to the minimum technical requirements specified by the Electric Vehicle Homecharge Scheme (EVHS) and comply with the electrical safety standards outlined in Building Regulations Part P.

Additionally, the charger must meet the IET Wiring Regulations as specified in BS 7671. It must be on a new and dedicated circuit, be individually protected by a residual current device (RCD) of Type A minimum, and have adequate electrical supply potential to operate at its rated capacity. To comply with BS EN 61851, the charge point must meet a minimum ingress protection (IP) rating of IP65 to shield it from water and dust.

There are also rules about where an EV charging unit can be placed. An EV charger is typically installed on the wall of a driveway or in a garage, offering convenience as it provides easy access to mains electricity and allows for parking nearby. However, it should not be within 2m of a public highway, scheduled monument or the land surrounding a listed building. EV chargers cannot be installed within 2.5m of any metal object linked to the electricity supply. This includes household fixtures like lights with metal casings or streetlamps.

Once the installation is completed, documentation of compliance with the relevant regulations is essential for record-keeping and future reference.

This may include electrical installation certificates, test reports and manufacturer’s installation instructions.

One direction

The next few years promise to be exciting times for the EV sector, with several factors that will help drive demand including increased production helping to lower vehicle prices, a greater choice of EVs, improved battery technology and more incentives for drivers to purchase these vehicles. This is a growing market and there is a lot of potential within it for specialised electrical contractors.