1. Appearance requirements
After the wire harness is processed, the surface should be smooth, the outer skin should be uniform, and there should be no pores, cracks, indentations, bumps, breakages, mottles, dirt, etc.
The wire harness and the terminal are crimped firmly without loosening. If welding with the terminal, it should be welded firmly without loose core.
2. Technical requirements
The insulation shall be tightly packed over the conductor and shall be easily peeled off without damaging the insulator, conductor or tin plating. The insulating surface should be flat and uniform in color.
The average value of insulation thickness should not be less than the specified nominal value, and the thickness of the thinnest point should not be less than 90%-0.1mm of the nominal value.
The insulated wire core should be able to withstand the AC 50Hz spark test specified in GB3048.9-83 as an intermediate inspection.
3. Color separation of insulated wire cores
Insulated cores shall be color-separated in colors that are easy to identify and hard to erase, and shall comply with the requirements of wire and cable marking methods. When necessary, other identification methods are allowed, but should be specified in the product standard. The preferred colors and color order are as follows:
a) Single-core cable: no preferred color;
b) Two-core cable: no preferred color;
c) Three-core cable: green/yellow bicolor, light blue, brown; or light blue, black, brown;
d) Four-core cable: green/yellow bicolor, light blue, black, brown; or light blue, black, brown, black or brown;
e) Five-core cable: green/yellow bicolor, light blue, black, brown, black or brown; or light blue, black, brown, black or brown, black or brown.
f) The green/yellow two-color is the color of the grounding core. When there is a green/yellow two-color grounding wire in the insulated wire of the cable, the other insulated cores are not allowed to use green or yellow.
4. Sheath
The sheath should be tightly squeezed over the stranded insulated core or inner sheath and should be easily peeled off without damaging the insulator or inner sheath. The surface of the sheath should be flat and uniform in color. The average value of the sheath thickness should not be less than the specified nominal value, and the thickness of the thinnest point should not be less than 85% (0.1mm) of the nominal value.
5. Mechanical strength
The crimped part shall be able to withstand the mechanical stress that may occur during normal use. Whether it is qualified or not may be checked by the following tensile strength test.
Apply the specified pulling force for 1min. When applying force, explosive force should not be used. This tensile force can also be applied by a tensile testing machine. The moving speed of the testing machine head should be between 25mm (1.0in)/min and 50mm (2.0in)/min, and there should be no shedding or breakage.
The wire should be subjected to the burning test, the flame on the surface of the sample should be extinguished by itself after the test, and the distance between the affected part of the scorch and the lower edge of the fixture on the test device should not be less than 50mm.
The wires should be able to withstand the specified AC 50Hz non-water immersion voltage test, and the insulated cores of two-core or more round sheathed wires should withstand the specified AC 50Hz non-water immersion voltage test.