What Size Cable Do You Need for a 22kW EV Charger?
For a 22kW three-phase EV charger drawing 32A per phase, use 6mm² 5-core cable on a dedicated 32A three-phase Type A RCBO circuit under BS 7671 Section 722. Under NEC, the 125% continuous load rule applies — use 8 AWG on a 40A three-phase circuit. For SWA installations, 6mm² 5-core SWA is standard.
Quick Reference: Cable Size for 22kW Three-Phase EV Charger by Standard
| Standard | Cable Size | Conditions | Reference |
|---|---|---|---|
| BS 7671 | 6mm² per phase | 32A three-phase, Type A RCBO per phase, Section 722 | Table 4D1A |
| NEC | 8 AWG | 40A three-phase circuit (125% rule), NEC 625 | Table 310.16 |
| AS/NZS 3008 | 6mm² | 32A three-phase dedicated circuit | Table 13 |
| IEC 60364 | 6mm² | 32A three-phase per IEC 61851 | Table B.52.4 |
Values shown are for copper conductors in typical domestic/commercial conditions. Actual size depends on installation method, ambient temperature, and cable length. Use our free cable sizing calculator for your exact scenario.
Typical Applications for a 22kW Three-Phase EV Charger
- 22kW three-phase commercial charger
- Workplace EV charging
- Fleet depot charger
- Multi-bay charging station
Calculate Your Exact Cable Size
These are general guidelines. Your specific installation needs exact calculation accounting for cable route length, installation method, ambient temperature, and cable grouping.
Frequently Asked Questions
Does a 22kW charger need three-phase supply?▼
Yes. 22kW at 230V single-phase would draw 96A, which is impractical. At 400V three-phase, the current is only 32A per phase — manageable with standard 6mm² cable and 32A MCBs.
What cable type for an outdoor 22kW charger?▼
Use 6mm² 5-core SWA (steel wire armoured) cable for outdoor installations. SWA provides mechanical protection for underground or surface-mounted runs. For indoor commercial car parks, 5-core PVC cable in conduit is acceptable.
Can all EVs charge at 22kW?▼
No. Most EVs have an onboard charger limited to 7kW (single-phase) or 11kW (three-phase). Only some models (e.g., Renault Zoe, Tesla Model 3 with upgrade) accept 22kW AC. The charger automatically limits to the vehicle's maximum.
What protection device for a 22kW charger?▼
A 32A three-phase Type A RCBO is required per BS 7671 Section 722. Some installations use a Type B RCD where the charger lacks built-in DC fault detection. Each phase requires individual overcurrent protection.
How many 22kW chargers can a 100A supply support?▼
A 100A three-phase supply can theoretically support three 22kW chargers (32A each = 96A). In practice, load management systems are used to share available capacity dynamically, allowing more chargers at reduced power.
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