Briefly on the basic knowledge of terminal blocks and key indicators

The task of the wiring system is to make a reliable mechanical and electrical connection of the wires. The terminal block adopts the crimping frame to effectively realize this function. The wire crimping frame is made of hardened and galvanized passivated steel. The steel screws that can withstand huge torque can firmly compress the wires. The copper conductive sheet is plated with a flexible tin-lead alloy to ensure air tightness, low resistance and permanent connection with the wire. The following points are loved by users and are widely adopted:

1.The contact surface is large, and the contact pressure is large, and the horizontal contact can be arbitrary.

2.With self-locking, anti-vibration and anti-loose functions. 3.Test jacks can be installed without maintenance.

4.The contact point is absolutely airtight and corrosion resistant.

5. Multi-strand wires are allowed to be connected directly without crimping the ends. 6) Easy to use.

7. Widely adopted globally, with high contact pressure

In the terminal block, contact force is one of the basic elements. If there is not enough contact pressure, no matter how good conductive materials are used, it will not help. Because, if the contact force is too low, there will be displacement between the wire and the conductive sheet, resulting in oxidation pollution, increasing the contact resistance and causing overheating. Take the DRTB2.5 crimping frame assembly as an example, only 0.8Nm of torque can be applied to the screw to produce an actual contact force of up to 750N, and the magnitude of this force has nothing to do with the wire cross section. Therefore, the use of the terminal crimping frame has a permanent connection that is not affected by any environment, large contact area, and large contact force. Small voltage drop The size of the voltage drop at the contact point is also one of the criteria for identifying the quality of the terminal block. Even if a small torque is applied to the screw, the voltage drop value is still much lower than the limit required by VDE0611. At the same time, the applied torque changes in a wide range, and the voltage drop is almost unchanged. Therefore, although the torque used by different operators is different, it will not affect the connection quality. This is another proof of the reliability of the terminal block using the crimping frame. The large contact force with self-locking function is meaningful only when it acts on the wire for a long time.

The crimping frame used in the terminal also has the greatest reliability in this respect. In the process of tightening the screw, the threaded tongue on the crimping frame springs up, thereby generating a reaction force against the screw. The change in the diameter of the wire caused by the temperature is offset by the elastic effect of the crimping frame itself, so there is no need to tighten the screws again. The wire-pressing frame on which the wire is pressed is subjected to an aging test for 168 hours under an environment of 130oC, and then a vibration test for 168 hours with 20 times the acceleration of gravity. After completing these more stringent tests than VDE0611, the pull-out force of the wire from the crimping frame is still higher than the VDE0611 requirement The value is six times higher, while the voltage drop remains the same. This unambiguously shows the maintenance-free nature of the crimping frame of the terminal block. Airtightness. Various environmental factors, such as temperature and air humidity, have been acting on the terminals for many years. Therefore, the terminals must be able to withstand the test of unfavorable environmental factors. According to the test and actual experience in DIN41640, Chapter 76, Even in the case of connecting flexible wires without crimping ends, the crimping frame can maintain its airtight performance.

Post time: Nov-18-2020