Working Principle Of Power Connectors

Generally speaking, people still have doubts and concerns about the conductivity of Power Connectors, thinking that such a few small thorns can withstand such a large current? Especially in today's era of rapid economic development in my country, the capacity of electric current has increased sharply. Can the insulated piercing wire clamp bear such a heavy responsibility?
Below we analyze the working principle of the parallel groove wire clamp and the insulated piercing wire clamp from the principle of current conduction between conductors.
The current conduction between conductors can be analyzed from two aspects: the mechanical contact area of ​​the conductor and the current conduction path.

1. Mechanical contact area of ​​conductor

From a microscopic point of view, the surface of the conductor is composed of countless uneven peaks and valleys. The smoother the surface of the conductor, the smaller the height difference between the peaks and valleys. When two conductors are in contact due to external force, their contact mainly exists in the form of peak-to-peak contact. Therefore, the actual mechanical contact area is much smaller than the nominal contact area designed for the wire clamp. According to literature analysis, the real mechanical contact area is about 7% of the nominal contact surface.

2. Current conduction path between conductors
1. Under the action of external pressure, the active aluminum oxide (Al2O3) layer on the aluminum-aluminum interface of the two conductors is squeezed or rubbed to partially rupture, allowing aluminum electrons to flow freely between peaks on the surface, forming a certain conductivity. The greater the pressure, the more peak-to-peak points of contact, and the smaller the contact resistance.
2. The conductivity of active aluminum oxide (Al2O3) itself makes the undamaged area also have a certain conductivity.
3. Due to the good plasticity of aluminum, when the two interfaces are pressed and contacted, part of the aluminum in the inner wall of the wire clamp will produce plastic deformation and enter the twisted gap of the outer layer of the wire, so that the effective contact area is increased, the mutual penetration between molecules is more active, and as the number of aluminum atoms in the oxide layer further increases, the conductivity on the electrical interface is improved.
Due to the creep of the wire, the wire becomes slightly thinner, the diameter is reduced, the effective contact area is reduced, and the resistance of the wire clamp increases. The reduction in the effective contact area is mainly caused by the reduction of the pressure of the wire clamp on the wire and the intensification of the oxidation of the contact surface.
Therefore, in order to improve the power supply reliability of the parallel groove wire clamp, multiple parallel groove wire clamps are often used on site.
The blade pierces the wire like a finger inserted into the water. According to relevant literature, its contact area is more than 1 times larger than that of the parallel groove wire clamp. Moreover, the piercing wire clamp has the advantages of easy installation and high reliability.
The wire pierced by the insulating piercing wire clamp should ensure that its breaking force is not less than 95% of the original wire's breaking force, and the wire cannot lose its due mechanical properties due to piercing.