Circuit group provides the overall number of service equipment for a certain load source group, such as trunk lines, switching devices, control systems, etc. The basic research content of traffic theory is to study the relationship between traffic volume, call loss and harness capacity, therefore. Wiring harness is an important basic concept in traffic theory.

In order to facilitate installation and maintenance, to ensure that the electrical equipment can work under the harshest conditions, the different specifications and different colors of the wires used in the electrical equipment of the whole vehicle are combined into one through reasonable arrangement, and the wires are bundled with insulation materials, which is both complete and reliable.

2. Normal selection of wire cross-sectional area and color scale

1) The correct choice of wire cross-sectional area

The electrical equipment on the car selects the cross-sectional area of the wire used according to the size of the load current. Electrical equipment working for a long time can choose 60% of the actual ampacity of the wire; Electrical equipment working for a short time can use 60%-100% of the actual ampacity of the wire.

2) Selection of wire color scale

For easy identification and repair, the wires in the harness are colored differently.

For the convenience of marking in the circuit diagram, the color of the wire is indicated by letters, and the color it represents is annotated in each circuit diagram.