Step 5 – High Voltage Wiring System

Procedure

1. Map all HV cable routes on diagram before cutting any cable
2. Select cable size: 35mm² for under 200A, 50mm² for 200–300A
3. Cut cables to length with 15cm service loops at each end
4. Crimp copper lugs using hydraulic crimper — 30+ tonnes force
5. Heat-shrink double-wall adhesive tubing over all terminations
6. Route cables in orange split-conduit, minimum 25mm diameter
7. Secure conduit every 300mm — never use zip ties on HV
8. Route HV cables away from 12V wiring by minimum 100mm
9. Avoid routing near sharp edges or moving suspension components
10. Install pyrofuse in positive cable for crash isolation
11. Install Hall-effect current sensors for BMS monitoring
12. Insulation resistance test: >1 MΩ between HV and chassis

Safety Warnings

1. Extreme Danger: 400V DC can kill instantly – no exceptions.
2. Use IEC 61482 arc flash PPE when working on HV
3. Insulation resistance test MUST pass before vehicle is powered
4. Inform emergency services: orange cable = high voltage vehicle

Pro tip

Keep a wiring diagram in the vehicle’s documentation wallet. Emergency services need to know where the manual service disconnect is. Orange cables are internationally recognised for HV in EVs.