What is the contact force of the basic elements of terminal blocks?
In the application of terminal blocks, contact force is the core element to ensure the reliability of electrical connections. If the contact force is insufficient, even if high-quality conductive materials are used, there may still be gaps between the wire and the conductive sheet due to mechanical displacement, leading to oxidation pollution, increased contact resistance, and even overheating faults. Taking the DRTB2.5 wire frame component as an example, only a torque of 0.8Nm needs to be applied to the screws to generate an actual contact force of up to 750N, and this force value is independent of the wire cross-section, ensuring the stability of the contact.
The influence of contact force on electrical performance is mainly reflected in two aspects: one is the matching between contact area and pressure. A larger contact force can expand the actual contact area and reduce contact resistance; The second is the durability of contact force. High quality wiring terminals can automatically compensate for changes in wire diameter caused by temperature fluctuations through the elastic design of the crimping frame, avoiding contact looseness caused by thermal expansion and contraction. For example, after 168 hours of high-temperature aging at 130 ℃ and 168 hours of rigorous testing with 20 times gravitational acceleration vibration, the wire pulling force is still 6 times higher than the standard value, and the voltage drop remains stable.
In engineering applications, the control of contact force needs to be combined with torque management. By standardizing torque tools, it can be ensured that the differences in torque applied by different operators do not affect the quality of the connection. At the same time, voltage drop testing can indirectly verify the effectiveness of contact force - even with a small torque applied, the voltage drop is still far below the requirements of VDE0611 standard, proving that the contact force design is reasonable. This design endows the terminal block with maintenance free features, significantly improving the long-term reliability of the electrical system.
