As the architecture of new energy vehicles (NEVs) evolves toward higher voltage, lightweight construction, and greater system integration, the reliability and safety of wiring harnesses have become a critical engineering focus. Acting as the “neural network” of the vehicle, harness systems require comprehensive protection against mechanical, electrical, and thermal challenges.
Within this context, braided sleeving has evolved from a simple harness organizer into a system-level protective component that directly impacts electrical safety, EMC performance, and long-term durability.
1.Key Application Areas — Where & Why
In NEVs, braided sleeving is deployed across multiple key harness zones, each with specific engineering objectives:
- High-Voltage Harness (Battery ↔ Inverter / Motor / DC-DC)
- Battery Module and Pack Internal Harnesses
- On-Board and External Charging Cables
- Power Electronics and Motor Bay (Inverter, PDU, DC-DC)
- Body Control and Signal Harness (CAN / LIN / Sensor)
2. Common Challenges & Engineering Responses
Wiring harnesses in NEVs face unique stresses such as high voltage, EMI interference, thermal aging, vibration, and maintenance complexity. Braided sleeving provides practical engineering countermeasures:
| Challenge | Engineering Response |
| High Voltage / EMI Risk | Use conductive or tinned copper wire braided shields with proper grounding and terminal treatment. |
| Thermal Cycling & High-Temperature Aging | Select high-temperature materials such as fiberglass, PTFE, or aramid blends; apply thermal insulation where needed. |
| Vibration & Mechanical Abrasion | Employ dense or dual-layer constructions (outer abrasion-resistant layer + inner warning color). |
| Assembly & Maintenance Efficiency | Use side-entry or zipper-style sleeves to reduce disassembly and rework time. |
| Compliance & Certification | Ensure materials meet UL94, IEC 60332, RoHS, and REACH standards. |
3. Material & Structural Trade-offs
Choosing the right material and structure helps balance cost, protection, and assembly efficiency:
- PET (Polyester) Braided Sleeve — Lightweight, abrasion-resistant, cost-effective, recyclable; ideal for low-heat areas.
- Fiberglass Sleeve — Excellent thermal resistance (up to 250°C short-term) and flame retardancy.
- Aramid / Kevlar® Reinforced Sleeve — Exceptional cut and tensile strength; ideal for critical high-protection zones.
- PTFE / Fluoropolymer Sleeve — Superior chemical and thermal resistance, low friction coefficient.
- Metallic / Tinned Copper Braid — Provides EMI shielding; requires proper grounding to ensure effectiveness.
Structural Options:
- Full Braided for continuous protection.
- Split or Side-Entry for easy installation and service.
- Dual-Layer for extreme abrasion zones.
- Self-Closing or Zipper Type for quick assembly and rework.
4. Design & Engineering Checklist
To achieve high reliability in NEV applications, the following parameters should be incorporated into the design phase:
- Functional Segmentation: Classify each harness by function (HV Power, LV Signal, Communication, Sensor).
- Temperature Rating: Define continuous and peak operating temperatures.
- Mechanical Protection: Specify abrasion, cut-through, and bending endurance requirements.
- EMC Requirements: Determine shielding coverage, grounding method, and connection design.
- Assembly Constraints: Evaluate space, process method (manual or automated), and maintenance needs.
- Aesthetics & Identification: Apply colors, stripes, or printing for traceability.
- Regulatory Compliance: Confirm material certification (UL94, IEC 60332, RoHS, REACH, ISO 26262).
- Maintenance Strategy: Consider modular designs for easy section replacement.
5. Validation & Testing Matrix
To ensure real-world reliability, validation testing should be included during prototype and PPAP stages:
- Thermal cycling and aging (LV124 / ISO 16750)
- Vibration and mechanical fatigue testing
- Flexural fatigue and bending endurance
- Abrasion and cut-through resistance
- Flammability and smoke density (UL94, IEC 60332)
- Salt spray and chemical resistance
- EMC shielding effectiveness
- Post-aging insulation integrity
6. Typical Engineering Scenarios
Scenario A: 800V High-Voltage Main Loop
Recommended configuration: outer PET or aramid abrasion-resistant layer + inner fiberglass thermal layer + local tinned copper shield braid with grounded terminals.
Validation focus: grounding continuity, short-circuit tolerance, thermal durability.
Scenario B: Battery Module Interconnect Harness
Recommended configuration: split-type fiberglass or aramid sleeve with visible warning color for maintenance visibility and easy replacement.
7. Actionable Guidelines for OEMs / Tier-1 Suppliers
- Define a "Sleeving Grade Matrix" based on harness function (HV, LV, Signal, Charging).
- Include test items in the supplier specifications (SOQ / PPAP) and require material certificates.
- Validate early during prototype phase to catch assembly or EMC issues.
- Standardize assembly tools and processes, such as crimping and grounding methods.
- Adopt modular maintenance designs for battery and power electronics harness sections.
8. Conclusion: From a "Finishing Part" to a "System Protector"
In NEVs, braided sleeving has evolved far beyond aesthetics or cable organization. It now serves as a critical protection system safeguarding electrical safety, electromagnetic compatibility, thermal stability, and long-term durability.
With advanced material engineering, structural innovation, and strict validation,MJ provides comprehensive braided sleeving solutions that help global OEMs and Tier-1 suppliers achieve higher reliability, easier maintenance, and improved overall system safety.