The cause analysis and solution of oxidation of harness wire

The cause analysis and solution of oxidation of harness wire
The harness is the wiring component connecting various electrical equipment in the circuit, which is composed of insulating sheath, wiring terminal, conductor and insulating binding material.

1、 Composition of wire harness

1. In order to facilitate the installation and maintenance and ensure that the electrical equipment can work under the worst conditions, the wires of different specifications and colors used by the electrical equipment of the whole vehicle are integrated through reasonable arrangement, and the wires are bound into bundles with insulating materials, which is both complete and reliable. 2. Normal selection of wire cross-sectional area and color code 1) correct selection of wire cross-sectional area. The electrical equipment on the vehicle selects the cross-sectional area of the wire used according to the load current. The actual working time of electrical equipment can be 60%; 60% - 100% of the actual current carrying capacity of wires can be used for electrical equipment working for a short time. 2) Selection of wire color code in order to facilitate identification and maintenance, the wires in the wire harness adopt different colors. For the convenience of marking in the circuit diagram, the colors of wires are represented by letters, and the colors represented are annotated in each circuit diagram.
(1) Human touch: in the production process of conductor, if employees directly touch the conductor with their hands without gloves, wet sweat adheres to the conductor surface or drops directly on the conductor, which will directly cause local oxidation and blackening of the conductor and affect the use of the next process.

(2) Packaging: the conductor coating can effectively prevent the contact between the conductor and the external humid air and avoid the oxidation of the conductor, but the chemical reaction between the PVC plastic film and the conductor is easy to occur, or in high temperature weather, some PVC films will precipitate some small molecular oily substances to pollute the conductor, resulting in the oxidation and discoloration of the conductor.

(3) Storage: in the southern region, especially in Jiangsu, Zhejiang and Shanghai, the conductor oxidation is particularly obvious in the plum rain season in June and July every year, mainly due to the high air humidity, which causes the conductor to be oxidized in contact with humid air for a long time.

2、 Solution

(1) During the production of conductors, operators must wear gloves to prevent the oxidation of local conductors caused by hand touch. In addition, it is also necessary to avoid oxidation caused by sweat dripping on the conductor, especially in hot summer.

(2) The plastic film with high temperature resistance and no precipitation is selected. It is recommended to use PE film, which has low cost, is not easy to decompose and precipitate, and has no chemical reaction in contact with copper conductor.

(3) The conductor shall be kept in a dry environment and the humid air shall be isolated. Therefore, the conductor warehouse needs to be closed and equipped with dehumidifier and thermometer. When the ambient humidity is greater than 75%, the dehumidifier must be turned on to reduce the ambient humidity and prevent conductor oxidation.