Wallbox installation and inspection: what the law requires, who may install and what the technician checks

"My neighbour will wire it, he's an electrician." A sentence that can get expensive. A wallbox is reserved electrical equipment, and without professional installation and an inspection you risk your insurance, your subsidy and your safety. Clearly, what the law and the standards require.

A wallbox is not an appliance, it is an electrical installation

You plug a kettle into a socket and nobody asks. A wallbox is a permanently connected electrical device with 11 to 22 kW of power that runs for ten hours at a stretch at 16 to 32 A per phase. The same rules therefore apply as for a distribution board or a heat pump: only a qualified person may install it and it must pass an inspection before it is put into service. The article describes the Czech rules; the underlying European standards (IEC 60364-7-722, EN 61851) are the same across the EU.

Which regulations apply

What the installation must include

• A dedicated circuit from the switchboard. The wallbox must not share a circuit with another appliance. For 11 kW a 3× 16 A breaker with B or C characteristic, for 22 kW 3× 32 A.
• Type A or B residual current device at 30 mA and 6 mA DC residual current protection (RDC-DD). The standard explicitly prohibits a type AC RCD. e:car WALL wallboxes have the AC 30 mA + DC 6 mA protection integrated, so only a breaker is needed in the board.
• Supply cable 5× 6 mm² up to 30 m, 5× 10 mm² for longer runs, in conduit, outdoor runs buried to the standard depth.
• Surge protection at the building supply; for outdoor installations also recommended on the wallbox circuit.
• Bonding and earthing per IEC 60364-4-41, loop impedance check.
• Location: the e:car WALL has IP54 protection and works from −30 to +50 °C, so it can be installed outdoors. Connector at 0.5 to 1.5 m height, away from gutter run-off.

The initial inspection step by step

1. Visual check. Cable routing, breaker, RCD, IP rating, labels and conformity with the design.
2. Measurements. Insulation resistance, fault loop impedance, continuity of the protective conductor, RCD function (trip current and time), DC residual current detection test.
3. Functional test. Charging simulation with an EVSE tester: states A, B, C, PE fault, diode fault, PWM current control verification.
4. Inspection report. Contains identification of the equipment, measurement results, the conclusion "capable of safe operation" and the date of the next inspection.

The inspection report is also the basis for the EV electricity tariff from the distributor, for the subsidy application and for the insurer in case of a claim.

Periodic inspections

The interval is set by the inspection technician according to the environment and use. For a home installation in a garage it is usually 5 years, for outdoor installations or company and public stations with high turnover 2 to 3 years. The operator of a public station also carries out regular checks under its operating rules. The wallbox monitors itself between inspections: the e:car WALL has a temperature sensor, monitors fault states and reports faults in the IONT.info app.

What if "a friend who is an electrician" installs the wallbox without an inspection

• The insurer may reduce or refuse a payout after a fire or damage to the car. An undocumented installation is the most common cause of disputes.
• The subsidy is not paid without an inspection report, which is a mandatory attachment.
• The EV tariff is not granted; the distributor requires the inspection.
• The warranty on the wallbox may be conditional on professional installation.
• Safety. Missing DC residual current protection means that a fault in the car's on-board charger will not trip an ordinary RCD.

What the inspection and installation cost

Checklist before the inspection technician arrives

• Design or at least a wiring diagram: breaker type, cable cross-section and length, route.
• Declaration of conformity and data sheet of the wallbox (for the e:car WALL downloadable from the website).
• Access to the main switchboard and any sub-board.
• A car or an EVSE tester for the functional charging test.
• The previous inspection report of the house installation, if you have it; the technician builds on it and need not inspect the whole building.
• Details for the report: address, owner, serial number of the station, installation date, installer.

Special cases

• Garage in an apartment building. The inspection covers the new part of the installation from the connection point. Basis: consent of the owners' association and a diagram of the connection to the shared board or the flat's meter. See charging in apartment buildings.
• Outdoor pedestal. A station on a pedestal by the driveway is exposed to weather and mechanical stress. It needs a buried cable in conduit, a foundation and surge protection; the technician checks the IP rating and earthing of the pedestal.
• Old aluminium wiring. Connecting a wallbox to aluminium wiring from the 1970s and 80s is usually not approved. The solution is a new dedicated copper supply straight from the main board, which is the most common installation anyway.
• Two wallboxes on one supply. The standard allows several charging points on one circuit only with load management. The dual-outlet e:car WALL double shares power between cars and has an RCD for each outlet.

Summary in five points

1. A wallbox is reserved electrical equipment; only a person licensed under Act No. 250/2021 Coll. may install it in the Czech Republic.
2. Each charging point needs its own circuit, a 30 mA type A or B RCD and 6 mA DC protection, never a type AC RCD.
3. An initial inspection is mandatory after installation; periodic ones follow the technician's determination, usually 2 to 5 years.
4. The inspection report is the basis for the subsidy, the EV tariff and the insurer.
5. Installation with inspection for a family house costs CZK 8,000 to 16,000 (EUR 320 to 640) excl. VAT; longer runs and trenching more.

Často kladené otázky