Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
IEC TS 63049: Installation Guidelines for Electric Vehicle Wireless Power Transfer
Technical Specification — EV WPT System Installation, Safety, and Commissioning
IEC TS 63049 provides technical guidelines for the installation of wireless power transfer (WPT) systems for electric vehicles. As a Technical Specification (TS), it serves as a pre-standard that consolidates best practices for site assessment, ground assembly embedding, coil alignment procedures, safety clearances, and electromagnetic field (EMF) exposure management. With the global EV market expanding rapidly and wireless charging emerging as a convenience differentiator, installation consistency is critical for interoperability, safety, and user acceptance.
Wireless EV charging operates in the 79–90 kHz band (aligned with SAE J2954). At these frequencies, the magnetic field decays rapidly with distance — but misalignment of just a few centimetres can reduce coupling efficiency from over 90 % to below 70 %, directly impacting charging time and thermal management.
Installation Requirements and Site Planning
The standard divides the installation process into four phases: site survey, ground assembly installation, vehicle-side assembly mounting, and system commissioning. Each phase has specific requirements for mechanical tolerances, electrical safety, and EMF measurement. The table below summarises the key installation parameters.
| Parameter | Requirement | Inspection Method |
|---|---|---|
| Ground clearance (top of pad to road surface) | 0 ± 2 mm (flush), or ≤ 15 mm proud | Dial gauge / laser profilometer |
| Lateral misalignment tolerance | ≤ ±75 mm (X/Y) for rated power | Alignment target + camera or inductive sensor |
| Vertical air gap range | 100–250 mm (class 1), 140–210 mm (class 2) | Gap measurement tool |
| Concrete cover over ground pad | ≥ 50 mm (reinforced), ≥ 80 mm (unreinforced) | Cover meter / core sample |
| EMF at bystander position (50 cm from edge) | ≤ 27 μT (ICNIRP 2010 reference level) | Isotropic field probe |
| Ingress protection (ground assembly) | IP67 minimum, IP68 recommended | Pressure test + immersion |
| Cable bend radius (power feeder) | ≥ 10 × cable outer diameter | Visual + gauge |
| Ground fault protection | RCD Type B, 30 mA trip threshold | RCD tester |
A frequently overlooked issue is the presence of buried metallic objects (rebar, utility conduits, ground grids) within the magnetic flux path. Eddy currents induced in these structures cause localised heating and reduce efficiency by 5–15 %. A ferromagnetic survey of the installation site is strongly recommended before committing the ground pad location.
Engineering Design Insights
Ground Pad Embedding and Thermal Management
The ground assembly (GA) is typically embedded in a concrete or asphalt pavement. IEC TS 63049 emphasises that the GA must be thermally coupled to the surrounding ground to dissipate the heat generated by I²R losses in the coil and ferrite shielding. Finite element analysis (FEA) simulations show that for a 11 kW system with 90 % efficiency, approximately 1.2 kW of heat must be dissipated. Without adequate thermal coupling, coil temperature can exceed 120 °C within 15 minutes of continuous operation, triggering power derating or shutdown. The standard recommends thermally conductive grout with a minimum thermal conductivity of 1.5 W/(m·K) around the GA.
Alignment and Communication Systems
The standard requires a secondary communication channel (typically using Bluetooth Low Energy or ISO 15118 PLC) between the vehicle assembly (VA) and GA for alignment guidance, power negotiation, and fault reporting. For automated parking systems, the alignment tolerance of ±75 mm must be maintained under all vehicle loading and suspension conditions. Active alignment systems using multiple small auxiliary coils on the GA can detect the VA position with ±5 mm accuracy and guide the driver via an HMI interface.
Proper installation documentation is as important as the physical work. IEC TS 63049 mandates a commissioning report that includes EMF survey results, ground resistance measurements, torque values on all fasteners, and photographic evidence of the cable routing. This documentation is essential for warranty validation and future maintenance.
Safety and EMF Compliance
ICNIRP 2010 guidelines limit public exposure to 27 μT at 85 kHz. The standard specifies measurement distances of 50 cm from the GA perimeter and 80 cm above the road surface. Active foreign object detection (FOD) using a balanced coil array is required to detect metallic objects (e.g., drink cans, tools) in the air gap that could heat up rapidly. If a foreign object is detected, the system must reduce power to below 100 W within 1 second.
Frequently Asked Questions
Q: Can wireless charging systems be installed in residential garages with existing concrete slabs?
A: Yes, but the slab thickness and reinforcement must be evaluated. Retrofitting typically requires coring a recess for the GA and ensuring adequate drainage. A pre-installation site survey per IEC TS 63049 is mandatory.
A: Yes, but the slab thickness and reinforcement must be evaluated. Retrofitting typically requires coring a recess for the GA and ensuring adequate drainage. A pre-installation site survey per IEC TS 63049 is mandatory.
Q: Does the standard cover bidirectional (V2G) wireless charging?
A: The current TS primarily addresses unidirectional grid-to-vehicle (G2V) charging. Bidirectional operation introduces additional safety, metering, and grid code requirements that are expected in a future amendment.
A: The current TS primarily addresses unidirectional grid-to-vehicle (G2V) charging. Bidirectional operation introduces additional safety, metering, and grid code requirements that are expected in a future amendment.
Q: What is the typical lifetime of an embedded ground pad?
A: With proper installation and IP68 sealing, the expected service life is 15–20 years, comparable to the pavement structure itself. The most common failure mode is water ingress through the cable gland, so meticulous attention to the gland sealing is essential.
A: With proper installation and IP68 sealing, the expected service life is 15–20 years, comparable to the pavement structure itself. The most common failure mode is water ingress through the cable gland, so meticulous attention to the gland sealing is essential.
Q: How does the system handle misalignment beyond the ±75 mm tolerance?
A: The control system will reduce power proportionally to maintain safe operating temperatures. If misalignment exceeds ±150 mm, coupling becomes too weak to sustain charging, and the system will shut down with a visual/audio alert to the driver.
A: The control system will reduce power proportionally to maintain safe operating temperatures. If misalignment exceeds ±150 mm, coupling becomes too weak to sustain charging, and the system will shut down with a visual/audio alert to the driver.
