Wallbox Installation – Electrical installation for EV charging stations
E-mobility is booming, and more homeowners are choosing their own wallbox for convenient, fast charging. But a wallbox is not a simple household device – it places high demands on the electrical installation. This guide covers technical requirements, cable sizing, RCD protection, grid registration and costs.
Quick info Wallbox
- 11 kW wallboxes are standard for homes (16A, 3-phase)
- Separate supply line from meter cabinet to wallbox required
- RCD Type B or EV (with DC fault current protection) is mandatory
Why a wallbox instead of a standard socket?
Theoretically, an electric car can also be charged from a standard household socket. In practice, however, this is problematic: Standard sockets are not designed for continuous loads of 10-16 A over several hours. There is a risk of overheating, cable fire and tripping of the circuit breaker.
Faster charging
11 kW wallbox charges 5-7x faster than standard socket (2.3 kW). An EV with 50 kWh battery charges in 4-5 hours instead of 20+ hours.
Maximum safety
Integrated residual current protection, overload protection, temperature sensors and tested connectors according to IEC 62196 (Type 2).
Comfort & control
App control, charging schedule, load management, PV surplus charging, RFID access control and energy metering.
Technical requirements for wallbox installation
1. Power connection and performance
Most wallboxes for private use have a charging capacity of 11 kW (3-phase, 16 A). This usually requires a dedicated circuit from the meter cabinet to the wallbox.
| Charging power | Power connection | Circuit breaker & RCD |
|---|---|---|
| 3,7 kW (16A, 1-phasig) | 230V, 1-phasig | 16A Typ B/EV |
| 11 kW (16A, 3-phasig) | 400V, 3-phasig | 16A Typ B/EV |
| 22 kW (32A, 3-phasig) | 400V, 3-phasig | 32A Typ B/EV |
2. Cable cross-section and wiring
For an 11 kW wallbox, a cable cross-section of at least 5× 2.5 mm² is required. For longer lines (>25 m), 5× 4 mm² or 5× 6 mm² should be used.
3. RCD protection for wallboxes
Wallboxes generate DC fault currents that are not detected by a standard Type A RCD. Therefore, either an RCD Type B or a Type A with additional DC fault current protection (6 mA) is required.
Wallbox installation process – Step by step
Location selection and planning
Determine mounting location (garage, carport, exterior wall), consider distance to vehicle (cable length!), check weather protection.
Commission electrician
Installation check by electrician: check house connection, inspect meter cabinet, plan cable route, obtain cost estimate.
Grid registration with network operator
Wallboxes from 3.7 kW must be reported, from 12 kW require approval. Registration usually carried out by electrician.
Installation and commissioning
Install line from meter cabinet to wallbox, install RCD and circuit breaker, mount and connect wallbox.
Testing and documentation
Measurement of insulation resistance, verification of protective measures, RCD trip test.
Wallbox installation costs
Total costs comprise hardware, installation effort and any extensions to the meter cabinet.
Wallbox (hardware)
11 kW wallbox: 400–1,200 €, depending on manufacturer, features and quality.
Material costs (cable, RCD, breaker)
Cables, RCD Type B or EV, circuit breaker: 150–400 €.
Electrical installation (labor)
Electrician work (mounting, connection, commissioning): 300–800 €.
Use funding
Check current funding programs! Often several hundred euros subsidy available.
Practical tips for your wallbox installation
1. Future-proofing: Preparation for second wallbox
Plan ahead: If a second EV might be added later, install a second conduit right away.
2. Plan for PV surplus charging
If you have a photovoltaic system: Choose a wallbox with PV surplus charging function.
3. Smart wallbox with network connection
Wallboxes with LAN/WLAN offer app control, energy metering and updates.
4. Permits and landlords
Tenants have had a legal right to a wallbox since 2020 – but costs must be agreed.
Conclusion: Wallbox installation is worthwhile – but only with a professional
Your own wallbox makes charging comfortable, fast and safe. However, installation requires proper electrical work and the correct RCD.
Important: Wallbox installation is not a DIY task! Always commission a qualified electrician.