How to choose a suitable terminal block

Terminal blocks belong to electrical connectors, and although they are very small compared to electrical equipment, they cannot be omitted. The various terminal strips in the market are dazzling, and how to choose the appropriate terminal for one's own equipment is a science.

When selecting a terminal block, it is necessary to first determine the required wire diameter, current size, wiring direction, application situation, wiring method, etc.

The wire diameter is to determine the size of the wire that needs to be connected; Current is the rated current that meets the needs of the equipment; The wiring direction generally includes front and side outgoing lines, which is designed to facilitate the operation of technical personnel and thereby improve work efficiency; The application range is wide: such as welded on circuit boards, installed on guide rails, and applied on frequency converters, etc; The wiring methods usually include frame type wiring (requiring a screwdriver), plate type wire pressing (requiring a screwdriver), cage type spring and disc type spring wiring, etc. The corresponding terminals include plug-in type, direct welding type, fence type, and spring type. Whether flange fixation is also a factor to consider.

There are certain rules that can be found in the correct selection and use of wiring terminals under different environmental conditions. Although there is no clear usage system in the industry, specific terminals can be selected based on specific usage environments and conditions. There are four practical principles that can serve as references.

Firstly, before setting the terminal, you need to understand the functions you need. According to the functional classification of terminals, there are ordinary terminals, safety terminals, test terminals, grounding terminals, double-layer terminals, double-layer conduction terminals, three-layer terminals, three-layer conduction terminals, one in and two out terminals, one in and three out terminals, double in and two out terminals, knife switch terminals, overvoltage protection terminals, marking terminals, etc. According to current classification, it can be divided into ordinary terminals (low current terminals) and high current terminals (over 100A or 25MM wires). Classified by appearance. It can be divided into rail type terminals, fixed terminals, circuit board terminals (PCB terminals), etc.

Secondly, it is necessary to consider the wire diameter of the wiring. For different wiring terminals, their size and wiring range are different. Usually, when using terminals, it is better to choose a slightly larger wiring range than the actual wire diameter. Because the current market standards are quite chaotic, if you choose a wiring aperture of the same size as the wire diameter, it is possible that the wiring range will become smaller due to terminals produced in the market that do not meet the standards, and the wire cannot be inserted into the crimping box.

Thirdly, the current meets the standard. For the guide rail terminal, which has been in the market for decades, there are regulations for current in the industry. Different models have specific current specifications, and the product must meet or exceed this standard.

Fourthly, use space. Different terminals can be selected for different space sizes. For example, in narrow spaces, you can choose double-layer wiring terminals or three-layer wiring terminals; For spaces with flexible installation positions, integrated terminals can be selected.