The middle terminals of a single component are represented by numbers in naturally increasing numbers. The same component group is preceded by a letter, such as the letter U1, V1, W1 of the three-phase communication system.

If there is no need to distinguish between the phases, the numbers 1.1, 2.1, and 3.1 can be used. The same type of component group.

A sign for an electrical terminal that is connected to a particular wire. The pressing mechanism of the terminal is a mechanism for generating pressure between the wire and the conductive strip. Only when sufficient pressure is generated, a low contact resistance can be ensured to form a good connection, so the reliability of the pressing mechanism directly affects the wire connection. Good or bad.

For threaded terminals, the screws, copper posts and pressure plates are important components that make up the compression mechanism; for unthreaded terminals, the spring or spring card is an important component of the compression mechanism.

The non-threaded terminal, the pressing mechanism is mainly a spring, so it is essential to select the spring. It is necessary to ensure sufficient contact pressure to ensure that the wire is not excessively damaged. The spring terminal is a relatively reliable screwless terminal.

When entering the line, the spring can be pressed by a push block or a screwdriver. After the line is fed, the spring is released, and the tension of the spring is used to tightly press the wire to generate sufficient contact pressure, and then the wire is used to smash the wire. Make it not loose or artificially pulled out.