High-Voltage Wiring Harness Routing Requirements for New Energy Vehicles: Ensuring Safety & Efficiency
In the world of new energy vehicles (NEVs), high-voltage wiring harnesses are the lifelines that power electric motors, batteries, and critical systems. But their performance depends on more than just quality components—how they’re routed and installed directly impacts safety, electromagnetic compatibility (EMC), and long-term reliability. Whether you’re designing a pure EV or a hybrid, here’s your guide to optimal high-voltage harness routing.
High-voltage harness routing starts with two golden rules, shaped by vehicle layout and electrical system needs:
- Proximity Priority: Minimize cable length by routing harnesses as directly as possible between components. This reduces material use, weight, and energy loss.
- Structured Routing: Choose between two primary layouts—layered routing or parallel routing—based on your vehicle’s electrical architecture.
High-voltage harnesses carry powerful currents, which can generate electromagnetic interference (EMI) that disrupts sensitive low-voltage systems (like control units or sensors). Layered routing solves this by physically separating them:
- Hierarchical Layout: High-voltage harnesses are routed on one layer (e.g., upper), and low-voltage harnesses on another (e.g., lower), creating a vertical barrier against EMI.
- Critical Spacing: The gap between layers depends on current levels, but a proven range is 200–300mm. Real-world testing confirms this distance effectively blocks EMI from high-voltage currents, keeping low-voltage signals stable.
- Why It Works: This layout acts like a shield, preventing cross-talk between systems—a must for vehicles with complex electrical setups.
When high and low-voltage harnesses must follow similar paths (common in hybrids), parallel routing keeps them organized without crossing:
- Side-by-Side Placement: Route harnesses alongside each other, 依附于 vehicle structures (e.g., frame rails or chassis brackets), but ensure they never overlap or cross.
- Hybrid-Friendly Design: Perfect for hybrids, where high-voltage battery cables and engine EFI (electronic fuel injection) 线束 often share space. Parallel routing isolates high-voltage EMI from engine control signals.
- EMC Protection: By avoiding intersections, this layout minimizes EMI leakage, ensuring both high-voltage power delivery and low-voltage control accuracy.
- Connector Access: Leave at least 200mm of clearance around all connectors. This makes plugging/unplugging easier during assembly, repairs, or replacements.
- Stress Relief: Ensure connections between harnesses and components have enough slack to absorb vibrations—no tight pulls that strain wires or terminals.
- High-Low Voltage Separation:
- For commercial vehicles: Keep parallel high- and low-voltage harnesses over 400mm apart.
- For passenger cars: Maintain a gap of over 200mm.
- If space is tight, route them perpendicular to each other to reduce EMI risk.
High-voltage harnesses are thick and rigid—poor securing leads to wear, noise, or even short circuits. Follow these steps:
- Smooth, Burr-Free Hardware: Use brackets, 线槽 (trunking), clips, or zip ties with rounded edges to avoid cutting into cables.
- Strategic Spacing: Fixing points (clips, brackets) should be no more than 400mm apart to prevent sagging or vibration-induced damage.
- Avoid Moving Parts: Keep harnesses at least 50mm away from moving components (e.g., suspension parts, pedals) to prevent snags or abrasion.
- Underbody Protection: For battery cables routed under the vehicle (common in pure EVs), add corrugated sleeves to shield against road debris, stone impacts, and water splashes. Where sleeves won’t fit, use plastic trunking to enclose and secure harnesses.
NEV high-voltage harnesses face harsh conditions—moisture, heat, dust, and mechanical stress. Here’s how to protect them:
- Sealing for Safety: Use gaskets and O-rings at connector interfaces and cable entry points. This blocks water and dust, preventing short circuits, arcing, or corrosion.
- Targeted Shielding:
- Engine Bay & Undercarriage: These areas need extra tough protection. Use plastic trunking or metal elbows to guard against water immersion, mud, and road scrapes. Trunking should be easy to assemble (e.g., snap-on lids) for quick maintenance.
- Heat & Flame Resistance: Harnesses near engines or radiators demand high-temperature, flame-retardant materials. Opt for orange corrugated sleeves or flame-resistant fabric sleeves—their bright color also serves as a visual warning for high voltage.
- Multi-Purpose Coverings: Beyond protection, coverings reduce noise from vibration, block radiant heat, and keep the engine bay looking neat.
Poorly routed high-voltage harnesses aren’t just a hassle—they risk EMI interference (disrupting sensors or controls), short circuits, or even thermal runaway. By following these guidelines, you ensure:
- Safety: Prevent electrical hazards and protect passengers.
- EMC Compliance: Avoid signal interference that could derail vehicle performance.
- Durability: Extend harness lifespan, reducing warranty claims and maintenance costs.
Whether you’re engineering a pure electric SUV or a plug-in hybrid, high-voltage harness routing is a critical detail that elevates your vehicle’s quality. Need help optimizing your design? Our team specializes in NEV electrical systems—let’s build safer, more efficient vehicles together.
Ready to perfect your high-voltage harness layout? Contact us for tailored solutions!
