# How to Run a Cable for an EV Charger By EV Charge Cables · Published 17 October 2026 **The short version** Running the supply cable for an EV charger is notifiable work a qualified installer carries out from the consumer unit to the wallbox, to BS 7671. - SWA for outdoor, buried or exposed runs; twin-and-earth only for protected indoor runs - Typical 7kW supply cable is 6mm2 or 10mm2, but the size is the electrician's call - Part P notifiable: DIY is strongly discouraged for EV circuits Running the cable for an EV charger means getting the fixed supply wiring from your consumer unit (fuse box) to the wallbox, and in England and Wales that is notifiable work a qualified EV installer must carry out, not a DIY job. The route, cable type and size are all chosen by the electrician to BS 7671, based on the run length, how the cable is installed and your existing supply. This guide gives a plain-English overview of what that work involves, and clears up the common mix-up between the supply wiring and the [charging lead](https://www.evchargecable.co.uk/collections/ev-charging-cables) we actually sell. [[QUOTE_CTA:Thinking about installation?|Start my quote]] ### Supply cable or charging lead: which "cable" do you mean? The word "cable" trips a lot of people up when they search, so let us separate the two meanings before anything else. The **supply cable** is the fixed wiring an electrician runs from the consumer unit to the wallbox. It is measured in mm² (cross-sectional area), buried or clipped in place, and never touched by you once it is installed. The **charging lead** is the Type 2 (or Type 1) lead that plugs between the car and the charge point. It is measured in length (metres) and current (amps), and it is the part you unplug and coil up each day. We make the charging lead, not the installation wiring. For the supply cable and the install itself, use a qualified EV installer. If you came here because you want the right lead for your car, the sizing you care about is length, so see our [length guide](https://www.evchargecable.co.uk/blogs/guides/what-length-ev-charging-cable-do-i-need) and [shop charging leads by car](https://www.evchargecable.co.uk/collections/ev-charging-cables) instead. ### How does the supply cable get from the fuse box to the wallbox? The installer starts by planning the shortest sensible route between the consumer unit and the wallbox position. Shorter runs tend to be simpler and help keep voltage drop within the limits in BS 7671, though the neatest path is not always the shortest if it means fewer wall penetrations or a tidier finish. From there the cable may run clipped along indoor surfaces, through trunking, through a wall to the outside, and then along an external wall or buried underground to reach the charge point. The method changes along the way, and so does the cable type used for each section. #### SWA for outdoor, buried or exposed runs Where the cable is outdoors, buried or otherwise exposed to damage, installers typically use steel-wire armoured (SWA) cable. The steel armour gives mechanical protection and a robust finish for external conditions. For a 7kW single-phase install (7kW is 32A on single-phase 230V, sometimes rounded to 7.4kW), the conductor size is commonly 6mm² for ordinary run lengths, with 10mm² used for longer runs or to keep voltage drop within limits. The exact size depends on the run length, the installation method, grouping, ambient temperature and is determined by the installer to BS 7671, so treat those figures as typical rather than a spec for your home. #### Twin-and-earth for protected indoor runs Twin-and-earth (T&E) cable is only suitable for protected indoor runs, for example clipped inside a garage or routed through trunking where it is not exposed to the weather or to knocks. As soon as the cable goes outside or underground, the design moves to SWA. #### Going through walls, clipping and trunking Where the run passes from inside to outside, the installer drills through the wall and seals the penetration. Along the way the cable is either clipped neatly to the surface at regular intervals or run inside trunking or conduit for a cleaner, better-protected finish. The choice is practical: trunking looks tidier and shields the cable, while direct clipping can be quicker on simple runs. #### Burying the cable If the route crosses a driveway or garden, the cable is usually buried. Buried cable must sit at an adequate depth, with warning tape above it and mechanical protection, all in line with the regulations. We will not give a depth here because the correct figure is set by the regs and the installer's assessment of the ground and what runs over it. SWA is the normal choice for buried sections because of its armour. ### Where does the circuit start: the consumer unit and RCBO The supply cable starts at a dedicated protective device in or beside the consumer unit. An EV charge point is given its own circuit, typically protected by an RCBO sized and specified by the installer, so it is independent of the rest of the house and has the right fault and shock protection for an outdoor charging point. If your existing board has no spare way or is an older type, the installer may fit a small additional enclosure rather than replacing the whole unit. What matters is that the EV circuit is dedicated and correctly protected, not shared off an existing socket ring. ### What does install day actually involve? A typical single-charger install is usually completed in a day, though awkward routes, long buried runs or board changes can extend that. The broad shape of the day looks like this. 1. The installer confirms the wallbox position and the cable route, then isolates the supply to work safely. 2. The supply cable is run from the consumer unit to the wallbox using the methods above, with the dedicated protective device fitted at the board. 3. The wallbox is mounted, connected and the circuit is tested, inspected and certified. 4. You get a demonstration of the charger and your certification and notification paperwork. For a fuller walk-through of the visit, including the survey beforehand, see [what to expect from an EV home charger installation](https://www.evchargecable.co.uk/blogs/guides/ev-home-charger-installation-what-to-expect). ### Why running your own EV circuit is strongly discouraged Installing or altering an EV charge point circuit in England and Wales is notifiable work under Part P of the Building Regulations. It must be carried out by a registered competent person, for example through NICEIC, NAPIT or Stroma, or notified to building control. Scotland and Northern Ireland have their own equivalent requirements. DIY is only lawful if the work fully complies with BS 7671 and is properly notified and inspected, and it is strongly discouraged for EV circuits. These are high-current outdoor circuits with specific earthing and shock-protection requirements, and getting them wrong is a genuine safety and insurance risk. The sensible route is a qualified EV installer who certifies the job. The installer also notifies your Distribution Network Operator (DNO) for the charge point. Some supplies or higher outputs need prior DNO approval before work can go ahead, which can add time to the project. ### What about load management and 22kW? If your main fuse or supply cannot comfortably take the extra current of around 32A, the installer may fit a CT-clamp load manager. This lets the charger back off automatically when the house is drawing heavily, which often avoids a costly supply upgrade. A 22kW charger is a different proposition. 22kW is three-phase, at roughly 32A per phase, and most UK homes are single-phase, so they cannot run 22kW at home without a three-phase supply upgrade. That is uncommon, expensive and needs DNO involvement. A 22kW install uses a multi-core SWA cable, for example a 5-core, sized to the installer's design. For whether the faster output is worth it, see [7kW vs 22kW](https://www.evchargecable.co.uk/blogs/guides/7kw-vs-22kw), [do I need a 22kW cable](https://www.evchargecable.co.uk/blogs/guides/do-i-need-a-22kw-cable) and [single-phase vs three-phase charging](https://www.evchargecable.co.uk/blogs/guides/single-phase-vs-three-phase-ev-charging). ### Route and method at a glance | Route type | Typical method | Notes | | --- | --- | --- | | Protected indoor run (e.g. garage) | T&E clipped to surface or in trunking | Only where the cable stays indoors and protected | | External wall run | SWA clipped to the wall or in conduit | Armour handles outdoor exposure and knocks | | Buried across a drive or garden | SWA underground | Adequate depth, warning tape and mechanical protection per the regs | | Through a wall | Drilled penetration, sealed | Transition point between indoor and outdoor methods | | Longer overall run | Often a larger conductor | Helps keep voltage drop within BS 7671 limits; installer confirms the size | ### What does the cable sizing depend on? For a 7kW home charger the supply cable is commonly 6mm² for ordinary run lengths, with 10mm² used for longer runs or to manage voltage drop. We are deliberately not telling you the size for your install, because the correct figure depends on the run length, the installation method, grouping, ambient temperature and is determined by the installer to BS 7671. A longer run often means going up a size to keep voltage drop within the regulation limits. That is exactly the kind of judgement your electrician makes on site, so treat typical sizes as background, not a shopping list. For more on the sizing question, browse our [EV charging guides](https://www.evchargecable.co.uk/blogs/guides). **Quick tool:** not sure how long a lead you need? Our free [EV charging cable length calculator](https://www.evchargecable.co.uk/tools/ev-charging-cable-length-calculator) turns your parking setup into a recommended length. ### Frequently asked questions #### Can I run the cable for an EV charger myself? It is strongly discouraged. Installing or altering an EV charge point circuit in England and Wales is notifiable work under Part P, so it must be done by a registered competent person or notified to building control. DIY is only lawful if it fully complies with BS 7671 and is properly notified and inspected, and the safety and insurance risks make a qualified EV installer the sensible choice. #### What size cable do I need to run to a 7kW EV charger? For a 7kW single-phase charger the supply cable is commonly 6mm² for ordinary run lengths, with 10mm² used for longer runs or to keep voltage drop within limits. The exact size depends on the run length, installation method, grouping and ambient temperature, and is confirmed by your electrician to BS 7671. #### Does the cable have to be armoured? For outdoor, buried or exposed runs installers typically use steel-wire armoured (SWA) cable because the armour gives mechanical protection. Twin-and-earth is only suitable for protected indoor runs, for example clipped inside a garage. Once the cable goes outside or underground, SWA is the normal choice. #### How deep does the cable need to be buried? Buried cable must sit at an adequate depth with warning tape above it and mechanical protection, all in line with the regulations. We will not quote a figure because the correct depth is set by the regs and the installer's assessment of the ground and what passes over it, so your installer determines it on site. #### Is the charging cable the same as the supply cable? No. The supply cable is the fixed wiring an electrician runs from the consumer unit to the wallbox, measured in mm². The charging lead is the Type 2 or Type 1 lead between the car and the charge point, measured in length. We make the charging lead, so if you want the right length for your parking, see our length guide and shop leads by car. #### Can I have a 22kW charger at home? Usually not without a supply upgrade. 22kW is three-phase, and most UK homes are single-phase, so running 22kW at home needs a three-phase supply upgrade, which is uncommon, expensive and needs DNO involvement. A 22kW install also uses a multi-core SWA cable sized to the installer's design. #### How long does it take to install an EV charger cable? A typical single-charger install is usually completed in a day, though awkward routes, long buried runs or a consumer unit change can extend that. The installer also notifies the DNO, and some supplies or higher outputs need prior approval before work, which can add time to the project. [[QUOTE_CTA:Thinking about installation?|Start my quote]] --- Canonical version: https://www.evchargecable.co.uk/blogs/guides/how-to-run-a-cable-for-an-ev-charger EV Charge Cables, EV charging cables matched to your car: https://www.evchargecable.co.uk. Some links in this article are Amazon affiliate links; as an Amazon Associate we earn from qualifying purchases at no extra cost to you.