In automotive wiring harnesses, low-voltage and high-voltage harnesses are two different types, playing different roles in the automotive electrical system.
Low-voltage wiring harnesses are typically used in the conventional circuits of a car, such as lighting, instrument panels, and door control systems. These harnesses generally operate at around 12V, which is low compared to the safe voltage for the human body, hence the name "low-voltage harness." Due to the low voltage, the insulation and protection requirements for the wires are relatively low; the outer layer of the harness is generally made of plastic insulation material, while the core consists of copper conductors.
Unlike low-voltage harnesses, high-voltage wiring harnesses are typically used in the automotive's electric motors and control systems, such as engine ignition and air conditioning compressors. These systems require higher voltages to drive the motors or control equipment, thus necessitating the use of high-voltage harnesses. High-voltage harnesses typically operate between tens and hundreds of volts, requiring higher insulation and protection standards for the wires. To ensure safety, the outer layer of high-voltage wiring harnesses is generally made of high-voltage resistant insulating materials, such as silicone rubber or polyimide. A metal shielding layer is also added to the outside of the harness to reduce the impact of electromagnetic interference.
Besides the voltage difference, low-voltage and high-voltage wiring harnesses also differ in design and manufacturing. Low-voltage wiring harnesses typically use single-strand or multi-strand copper wires, while high-voltage wiring harnesses require thicker wires, sometimes using braided or stranded wires to increase mechanical strength. Furthermore, high-voltage wiring harness connectors usually need to withstand higher current and voltage, making their design more complex and robust.
In automotive design and manufacturing, the selection and use of low-voltage and high-voltage wiring harnesses must be determined based on the specific circuit requirements. Improper use or incorrect installation can lead to circuit failures, equipment damage, or even safety accidents. Therefore, understanding the characteristics and usage methods of low-voltage and high-voltage wiring harnesses is crucial for personnel engaged in automotive circuit design and maintenance.
