Discussion on wet zone sealing of automobile wiring harness

Discussion on wet zone sealing of automobile wiring harness

The Automotive connector Single Wire Seal connects the electrical parts of the whole vehicle together, which is the neural network of the automobile, and guarantees the normal operation of the electrical functional parts of the automobile. With the increasing level of modern automobile electronization, the durability and reliability of wire harness are required to be higher, especially for the wire harness in the engine room and the harsh environment under the vehicle body.

A wet area

We put the car engine room and under the car body part exposed to the air can be frequently affected by rain, water area called wet area; Relatively, the cab, luggage compartment is basically not affected by rain, water part of the dry area.

Seal wet area

The electrical components and wiring harnesses in the ten zones are less affected by the environment of high temperature, high humidity, chemicals, dust, etc. However, electrical parts and wiring harnesses in wet areas are greatly affected by the environment, so they must be well protected against high temperature, water and corrosion. If the sealing of the electrical parts in the wet area is not good, it will lead to water inside the electrical parts, which will cause the electrical parts' internal short-circuit, rust, ablative and other faults and lead to abnormal electrical functions or failure. Similarly, poor sealing of wiring harness interconnections and plug-in connections can also cause flooding and electrical failure. Therefore, we define the wet zone sealing as the sealing treatment of the electrical function parts and wiring harness connection parts in the wet zone of the automobile to isolate the water and ensure the normal and reliable protective operation of electrical functions.

There are two main ways to enter water into electrical system: one is to rely on the gravity of water to infiltrate into electrical module or indirectly infiltrate into electrical module through Automotive connector Seal, wiring harness point, wiring harness iron point; Second, due to siphoning, water molecules enter the electrical module through the gap between multiple copper wires.

Siphon phenomenon refers to the phenomenon that liquid flows through the curved pipe to the higher liquid level and flows downward to the lower liquid level under the action of intermolecular gravity and atmospheric pressure, as shown in figure 1. In the automobile, when the electrical module is working, the internal temperature rises, and when the stop working temperature decreases, the internal pressure decreases. At this time, under the action of the pressure difference, water molecules penetrate into the electrical module through the gap of the poorly sealed multi-wire, causing electrical fault.