What is the characteristic requirement of automotive wiring harness?

What is a car wiring harness?

Like the nerves and blood vessels of a car, the automotive wiring harness carries the transmission of the car's power and signals and is an important component of automotive parts. The automotive wiring harness is mainly composed of three parts: cables, wrapping materials, and connectors (terminals).

According to the voltage, the automotive wiring harness can be divided into high-voltage wiring harness and low-voltage wiring harness. The high-voltage wiring harness voltage is 300V and above, and is mainly used for driving power transmission of new energy vehicles; the low-voltage wiring harness voltage is below 60V, and the general automotive voltage is 12V, which is mainly used for the transmission of vehicle signals. According to the composition, it can be divided into engine wiring harness, instrument wiring harness, lighting wiring harness, air conditioning wiring harness, and auxiliary electrical wiring harness.

Characteristics requirements of automotive wiring harnesses

In addition to its own performance requirements, automotive wiring harnesses also have complex operating environments. For example, engine wiring harnesses need to withstand the high temperature and vibration environment of the engine compartment; door wiring harnesses need to have enough bends to ensure the normal operation of door components. Different environments require wiring harnesses to have different characteristics, which can be summarized into the following four categories:

Heat resistance: According to the working environment temperature of the wiring harness wire, choose wires with different temperature resistance grades. The wires in the passenger compartment can choose wires with a temperature resistance grade of 90℃; the wires in the engine compartment can choose wires with a temperature resistance grade of 180℃; the wires crossing the above two areas should choose wires with a temperature resistance grade that meets the temperature requirements of both areas.

Wear resistance: The wire itself should be able to prevent the insulation damage and leakage caused by wear at the wiring part. When designing, the wire should be kept away from parts that are prone to vibration as much as possible to prevent the wire harness from being worn and broken. If it is unavoidable, wrapping tape or external corrugated tube can be used.

Flame retardancy: Flame retardancy refers to the regulation that the burning time and range of parts will be controlled within a certain range after catching fire.

Bending property: The repeated bending property of the bendable parts is required. The bending degree, the number of bending times allowed, and the ambient temperature of the parts should be set according to the usage. For example, the rubber sleeve for car doors is required to reach 180°/100,000 times/-30~80℃.

As a professional general instrument manufacturer, ITECH can provide comprehensive testing solutions for heat resistance testing of automotive wiring harnesses.

ITECH Case Study

Case 1

Test requirements: A customer tests the temperature change of the wiring harness by adding current to the wiring harness under test.

Test equipment: The customer selected ITECH programmable DC power supply IT6015D-80-450 as the power supply. Later, due to the upgrade of the client's products, the test demand current index was upgraded to more than 600A. After connecting two products of the same model in parallel, the test index can be achieved.

Case 2

Test requirements: During the temperature rise test, a customer installed the connector to be tested in the test equipment, passed a current of more than 1000A, repeatedly increased or decreased the input current, observed the changes in the output current and temperature value, and determined whether the connector can be used in new energy vehicles.

Test equipment: The customer chose ITECH bidirectional programmable DC power supply IT6045C-80-1350 to complete the temperature rise test. This model has a maximum current of 1350A, which fully covers the customer's test. It also has fast dynamic response time, panel LIST editing, and master-slave parallel expansion current and power functions. If the user has a higher current upgrade test requirement in the future, ITECH products can also cover it perfectly.

Case 3

Test requirements: A customer is engaged in automotive electronic connectors and needs to verify the stability of the wiring harness during the production process.

Test equipment: ITECH programmable DC power supply IT6534C and high-power programmable electronic load IT8902E are used to complete the temperature rise test of the wiring harness. The temperature rise of the wiring harness is verified through continuous high current output, thereby verifying the stability of the wiring harness.