Basic knowledge of terminal blocks and selection of key indicators The task of the wiring system is to make mechanical and electrical connections to the conductors. This function can be effectively implemented by using a crimping frame at the terminal block. The crimping frame is made of quench hardened and galvanized passivated steel. Steel screws that can withstand large moments can firmly press the conductive copper sheet of the conductor to be coated with flexible tin. – Lead alloy, which ensures airtightness, low resistance and permanent connection with the wire. It is widely used by users and is widely used:
1) The contact surface is large, and the contact pressure is large, and it can be arbitrarily contacted horizontally.
2) It has self-locking, anti-vibration and anti-loose functions.
3) Test socket can be installed without maintenance.
4) The contact point is absolutely airtight and resistant to corrosion.
5) Multiple strands allow the crimping of the ends without direct connection.
6) Easy to use.
7) Widely adopted worldwide
Contact force is one of the basic elements in the terminal block. If there is not enough contact pressure, the use of even better conductive materials will not help. Because, if the contact force is too low, displacement between the wire and the conductive sheet will occur, thereby causing oxidative contamination, which increases the contact resistance and causes overheating. Taking the DRTB2.5 crimping frame assembly as an example, an actual contact force of up to 750 N can be generated by applying a torque of 0.8 Nm to the screw, and the magnitude of the force has nothing to do with the wire cross section. Therefore, the terminal crimping frame has a permanent connection that is free from any environmental influence, large contact area, and large contact force. The voltage drop at a small voltage drop is also one of the criteria for identifying the quality of the terminal block. Even with a small force applied to the screw, the voltage drop is still much lower than the limit required by VDE0611. At the same time, the applied torque varies over a wide range and the voltage drop is almost constant. Therefore, although different operators use different torques, they do not affect the connection quality. This is another proof of the reliability of the crimping frame used in the terminal block. The contact force with a large self-locking function only makes sense if it acts permanently on the wire.
Post time: Jul-21-2018