In the power automation connection system, the emergence of terminal blocks has facilitated operation and maintenance, with a simple structure and a wide variety of types, providing thousands of solutions for industry partners. When the terminal in the connection is short circuited due to burning out, the application advantages of the terminal become apparent. After power failure, the burnt terminal can be immediately removed and replaced with a new product of the same model, greatly reducing the entire repair time. As a terminal itself, it mainly includes the following connection technologies:
1. Screw connection
Screw connection is a connection method that uses screw type terminal blocks, and attention should be paid to the maximum and minimum cross-sections allowed for connecting wires and the maximum tightening torque allowed for screws of different specifications.
2. Welding
The most common type of welding is soldering. The most important aspect of soldering connection is the continuity of metal between the solder material and the surface being soldered. For cold pressed terminals, weldability is important. The common coatings for the welding end of the wire ring terminal are tin alloy, silver, and gold. The common welding ends of spring type contact include welding plate, punch eye welding plate, and notch welding plate. The common welding ends of pinhole type contact include drilled arc notch type.
3. Crimp connection
Crimping is a technique used to compress and displace metal within specified limits and connect wires to contact pairs. A good crimping connection can generate metal mutual melting flow, causing symmetrical deformation of the material between the wire and the contact. This type of connection is similar to cold welding, which can achieve good mechanical strength and electrical continuity, and it can withstand more harsh environmental conditions. At present, it is generally believed that using the correct crimping connection is better than soldering, especially in high current situations where crimping must be used. Special crimping pliers or automatic or semi-automatic crimping machines must be used during crimping. The correct wire barrel for contact pairs should be selected based on the cross-sectional area of the cold pressed end wire. It should be noted that crimping connections are permanent connections and can only be used once.
4. Wrap around
Winding is the process of directly wrapping a wire around a contact post with sharp edges. When winding, the wire is wound under controlled tension, pressed and fixed at the corners of the contact piece winding column to form an airtight contact. There are several requirements for winding wires: the nominal diameter of the wire should be within the range of 0.25mm to 1.0mm; When the diameter of the wire is not greater than 0.5mm, all rights reserved by Control Engineering Network. The elongation of the conductor material shall not be less than 15%; When the diameter of the wire is greater than 0.5mm, all rights reserved by Control Engineering Network. The elongation of the conductor material shall not be less than 20%. The tools for winding include winding guns and fixed winding machines.
5. Piercing in succession
Puncture connection, also known as insulation displacement connection, is a novel terminal technology invented by the United States in the 1960s. It has the characteristics of high reliability, low cost, and easy use. Currently, it has been widely used in various printed board terminal blocks, cold pressed terminals, and ring terminals. It is suitable for connecting ribbon cables. When connecting, there is no need to strip off the insulation layer of the cable. The tip of the "U" shaped contact spring of the terminal block is inserted into the insulation layer, so that the conductor of the cable slides into the groove of the contact spring block and is clamped, forming a tight electrical connection between the cable conductor and the terminal spring block. It only requires simple tools and must use cables with specified wire specifications.
