Guidelines for High Voltage Wiring Harnesses

The high-voltage wiring harness of new energy vehicles is a power transmission carrier that connects key components such as high-voltage battery systems, drive motors, and charging devices. It is responsible for energy distribution, signal transmission, and electromagnetic shielding functions, and is regarded as the "neural network" of the high-voltage system of new energy vehicles. Its working voltage is usually above 300V (some models reach 600V), much higher than the low-voltage wiring harness of traditional fuel vehicles (12V/24V).

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Main components and structure

Connector: Ensure fast insertion and stable connection of high-voltage circuits, in compliance with LV series or USCAR industry safety standards
Wire: Large section copper core cable (such as 2.5-95mm ²) is used, and the outer layer is wrapped with high insulation materials such as silicone and TPU
Covering: including corrugated pipes, flame-retardant tape, etc., used for physical protection and high temperature resistance protection
Shielding layer: wrapped in metal braided layer or aluminum foil to suppress electromagnetic interference

Classification and Application Scenarios

type	connection path	Typical scenario
High voltage harness for power battery	Power battery ↔ High voltage distribution box	Main energy transmission channel, supporting high current
Fast charging/slow charging wire harness	charging port ↔ High voltage distribution box/car charger	Supports fast charging (DC) and slow charging (AC)
Motor controller wiring harness	High voltage distribution box ↔ motor controller	Energy regulation of drive motor
High voltage accessory wiring harness	High voltage distribution box ↔ DC/DC、 Air conditioning compressor, etc	Vehicle mounted equipment power supply and thermal energy management

Selection and Design of High Voltage Connectors

The selection of high-voltage connectors is also an important consideration in the design process. High voltage connectors are mainly responsible for the connection and transmission of high voltage and high current, and play an important role in ensuring human safety. When selecting, it is necessary to consider functions such as high voltage resistance, protection level, loop interlock, and shielding.

High voltage harness shielding design

High voltage wiring harnesses also need to consider shielding design. Due to the strong electromagnetic interference generated by high-voltage wire harnesses when transmitting high voltage electricity, it is necessary to use wire with braided shielding mesh, and when selecting high-voltage connectors, try to choose connectors with shielding design to suppress the electromagnetic interference generated by high-voltage wire harnesses.

High-voltage-harness-shielding-design

Sealing and Waterproof Design for High Voltage Lines

In order to improve the mechanical protection and dust-proof and waterproof performance of high-voltage wire harnesses, protective measures such as sealing rings are used between the connectors and at the positions where the connectors are connected to the cables to prevent water vapor and dust from entering, thereby ensuring a sealed environment for the connectors and avoiding safety issues such as short circuits, sparks, and leakage between contacts.

At present, most high-voltage wire harnesses are protected by wrapping materials, which mainly have the functions of anti-wear, noise reduction, radiation heat source isolation, and aesthetics. Generally, orange high-temperature resistant and flame-retardant corrugated tubes or orange high-temperature resistant and flame-retardant cloth sleeves are used for complete wrapping.

high-voltage-wire-harnesses