Industry News

What are the key requirements for the selection of terminal blocks?


In the terminal block, the contact force is one of the basic elements.

If there is not enough contact pressure, no matter how good the conductive material is, 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. Taking the DRTB2.5 crimping frame assembly as an example, it only needs to apply a torque of 0.8Nm to the screw to generate an actual contact force of up to 750N, and the magnitude of this force has nothing to do with the cross section of the wire. Therefore, the use of the terminal crimping frame has a permanent connection that is not affected by any environment, has a large contact area and a large contact force. The magnitude of the voltage drop at the contact point with small voltage drop is also one of the criteria for identifying the quality of the terminal block. Even with a small force distance applied to the screw, the value of the voltage drop is still well below the limits required by VDE0611. At the same time, the applied torque varies over a wide range and the voltage drop is almost constant. Therefore, although the torque used by different operators is different, it will not affect the quality of the connection. This is another proof of the reliability of the crimping frame used for the terminal block. Self-locking high contact forces are only meaningful if they permanently act on the conductors. 

The wiring work terminal can use the crimping frame, which also has the greatest reliability in China in this regard. 

In the process of tightening the set screw, the threaded tongue on the crimp frame does not spring upwards, so we have a reaction force that affects the screw. The change of the diameter of the wire due to different temperature changes is offset by the elastic effect of the content of the crimping frame itself, so there is no need to tighten the screw again. 

Air tightness is a number of environmental factors that affect the terminal for many years, such as temperature, air humidity, etc., so the terminal must be able to withstand the test of adverse environmental factors. There is no crimp terminal when connecting the flexible wire, and the airtightness of the terminal is still maintained.