What Is a Screw Terminal?

A terminal is an accessory product used to achieve electrical connections, and is industrially divided into the category of connectors. With the increasing degree of industrial automation and the increasingly strict and precise industrial control requirements, the use of terminal blocks has gradually increased. With the development of the electronics industry, the range of use of terminal blocks is increasing, and the types are increasing. In addition to PCB board terminals, the most widely used are hardware terminals, nut terminals, spring terminals, and so on.

This standard

wiring

1. The tightening wiring should be moderate in strength to prevent the bolts and nuts from being fastened by excessive force. It is found that the bolts and nuts that have been fastened are replaced in time. It is strictly forbidden to work.

2. When tightening or loosening a screw with a screwdriver, you must force the screwdriver to tighten the screw, and then tighten or loosen it to prevent the screwdriver and the screw from slipping, which will cause damage to the screw and make it difficult to disassemble, especially the common open in the hanging box.

3. It is found that the bolts and nuts that are difficult to disassemble, do not act recklessly to prevent deformation and make it more difficult to disassemble. Appropriate knocking should be given, or screw loosening agents, dilute hydrochloric acid, etc. should be dismantled later.

4. Do not use a vise to tighten or loosen the bolt and nut to prevent damage. When using a spanner, adjust the opening to prevent the bolt and nut from being damaged and deformed, which makes it difficult to disassemble.

5. The same terminal allows up to two wires of the same type and specification.

6. For the terminals that are easy to loose or easy to contact, the wire joint must be fastened to the terminal with a "?" Type to increase the contact area and prevent loosening.

7. When the wire joints or wire noses are connected to each other, it is strictly prohibited to install non-copper or poorly conductive gaskets in the middle.

8. When the wire joint is connected, the contact surface should be smooth and free of oxidation. When the connection nose or copper bar is connected, the contact surface can be cleaned and coated with conductive paste, and then tightened.

9. When connecting temporary wires, the single-lead flexible cord is required to fold the connector in half once, and then connected to the lower opening of the air opening; the single-core hard wire should be connected to the lower opening of the air opening in the form of "?".

10. For wiring of 30KW and above motors, it is not allowed to cross between gaskets with poor electrical conductivity, such as galvanized nuts, flat washers, spring washers, etc.

11. When using insulating tape to wind cables or other equipment to be protected from insulation, the insulation layer should be wound from one end to the other-at a ratio of 1/2, and at least back and forth. ^[5]

With the fierce competition in the terminal market, grasping the market development quickly and effectively has become the key to the success of enterprises and decision makers. Market analysis is a scientific and systematic job that directly affects

Female and male terminals

1. The material of the female or male terminal should be copper alloy, or electroplated copper alloy, nickel, or nickel alloy. ^[6]

The current rating of components in Europe is determined by monitoring the temperature of the metal conductor as the current increases. When the temperature of the metal pin is 45 ° C higher than the ambient temperature, the surveyor takes the current at this time as the rated current value (or maximum current value) of the device. Another item of the IEC specification is the allowable current value, which is 80% of the maximum current. In contrast, the UL standard will make the current value of the metal conductor 90% higher than the ambient temperature at 90% as the nominal current value of the device. ^[6]

It can be seen that the temperature of the metal conductor part is a very important factor in all applications. This is even more important for industrial equipment. Because industrial equipment usually needs to work in the environment up to 80 ° C. If the temperature of the terminal block is 30 ° C or 45 ° C higher than this temperature, the temperature of the terminal block will exceed 100 ° C. Depending on the nominal value type and insulation material used for the selected device, the product must operate at a current lower than the rated value in order to ensure that they can work reliably within the desired temperature range. Sometimes, materials suitable for compact packaged devices may not meet heat dissipation requirements well, so the current used by such terminal block devices must be significantly lower than the rated value. In this way, it shows the importance of how to choose the terminal type.

With the globalization of enterprises, the need to design systems that can be sold globally, so system designers are increasingly using terminal products made in other countries. Because nominal measurement methods are used in Europe, it is common practice in Europe for devices to be used below the nominal value in the design. However, many American designers are not familiar with this concept. Without understanding the differences between standards, it will be difficult in the design process ^[6]