The principle and method of marking terminals with alphanumeric symbols, and the two ends of a single component are indicated by two connected numbers.

Each terminal in the center of a single element is indicated by a natural number in the sequence of increasing numbers. The same component group shall be preceded by letters, such as letters U1, V1, W1, etc.

If it is not necessary to distinguish the phases, the numbers 1.1, 2.1 and 3.1 can be used. Component group of the same kind.

Marking of electrical terminals connected to specific wires. The pressing organization of the terminal is the organization that produces pressure between the wire and the conductive strip. Only when the pressure is satisfied, can the lower touch resistance be ensured and the excellent connection be formed. Therefore, the reliability of the pressing organization directly affects the quality of the wire connection.

For threaded terminals, screws, copper columns and pressure plates are important components of the compression structure; for non threaded terminals, tension springs or tension spring cards are important components of the compression structure.

For the non threaded terminal, the compression organization is mainly the tension spring, so the material selection of tension spring is very important. It is necessary to ensure that there is enough touch pressure and the wire will not be excessively damaged. The tension spring terminal is a relatively reliable non threaded terminal at present.

When entering the wire, the tension spring can be pressed by a push block or a screw driver. After entering the wire, the tension spring is released, and the return force of the tension spring is used to press the wire tightly to meet the touch pressure. Then the edge of the tension spring is used to strangle the wire, so that it will not be loose or pulled out artificially.