Copper grounding copper bar industry knowledge popularization

 

Copper grounding copper bars are core metal processing components used in power systems to connect electrical equipment and grounding devices. Its core function is to provide a low-impedance discharge path for fault currents, lightning currents or high-frequency interference currents, ensuring that equipment maintains potential stability under abnormal working conditions and protecting the safety of personnel and equipment. As a high-precision Vertical Copper Bonding Busbar, the performance of the copper grounding busbar is directly related to the stability and safety of the entire power system. It is especially widely used in distribution cabinets, frequency converters, power cabinets, communication base stations, rail transit and other scenarios. Copper grounding copper bars are usually made of high-purity copper materials, with a copper content of not less than 99.92% and a total impurity content controlled within 0.08%. This high-purity ratio not only ensures excellent conductivity but also takes into account good corrosion resistance.

 

Its typical hardness is about 65% (based on the annealed state), and its softening temperature can reach 518°C. This means that under high-temperature overload or short-circuit transient heating conditions, the copper grounding copper bar can still maintain structural integrity and will not lose its mechanical support ability due to softening. The standard product length can be customized according to project needs, with a maximum length of 7981mm. The allowable length deviation is controlled within ±0.3mm. The fine processing standard with a grain size of 0.17 ensures the fit with the equipment terminals and grounding busbar during installation. In addition, the copper grounding copper bar supports on-demand cutting, punching, bending and other secondary processing services to adapt to the requirements of different cabinet structures and wiring layouts. As the core component of the Wall Mounted Copper Ground Bar Kit, it can effectively utilize the side space inside the cabinet and reduce the occupation of the main bus duct in the wall-mounted installation scenario.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The material system of copper grounding copper bars is mainly high-purity electrolytic copper. Typical grades include T2 copper or C11000, with a copper content of ≥99.9% and a total alloying element content of no more than 0.5%. This material ratio maintains extremely low resistivity (approximately 0.01724Ω·mm²/m), and at the same time moderately improves the material's creep resistance and stress relaxation resistance through trace alloying, making it less likely to produce permanent deformation under long-term bolt tightening pressure or thermal cycling. The hardness index is about 65% (measured on the HV or HB scale), which is in the semi-hard range. It not only ensures sufficient mechanical strength to resist bumps and bends during installation, but also retains good ductility to support bending and forming. The softening temperature reaches 518°C, which means that when a short-circuit fault causes an instantaneous temperature rise in the conductor, the copper grounding bar will not quickly lose its load-bearing capacity, buying time for the action of protecting electrical appliances. In terms of dimensional accuracy, the maximum length can be 7981mm, with an allowable deviation of ±0.3mm.

 

This tolerance level is far better than that of ordinary profiles, ensuring the consistency and contact reliability of multi-section splicing or long-distance laying. The granularity parameter 0.17 reflects the control level of the material's grain size. Fine grains are conducive to improving the material's fatigue resistance and surface finish. In terms of surface treatment, depending on the application environment, bare copper, tin plating, nickel plating or passivation treatment can be provided. Among them, the Tinned Copper Ground Bar for Underground System uses a tin plating layer thickness of 3-8 μm, which can effectively prevent the copper substrate from being electrochemically corroded by soil moisture, acid and alkali substances and stray current in the buried environment, extending the service life to more than 30 years. The tin plating layer also has good solderability, which facilitates the connection and convergence of ground cables on site.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The production process of copper grounding copper bars requires multiple precision processes such as smelting, rolling, cutting, and surface treatment. The oxygen content and impurity elements (such as sulfur, iron, lead, etc.) need to be strictly controlled during the smelting stage to ensure that the copper purity reaches more than 99.9%, because any trace amount of impurities will significantly reduce the conductivity and increase the risk of local corrosion. The rolling process uses a cold working process (multi-pass cold rolling) to increase the hardness and tensile strength of the material while maintaining sufficient elongation to prevent bending and cracking. The internal grains of cold-rolled copper are elongated to form a fibrous structure, which helps improve the creep resistance of the material. High-precision CNC sawing machines or water jet cutting equipment are used for cutting. The verticality of the cutting section is controlled within 0.1mm. There are no burrs or oxidative discoloration, which reduces the workload of subsequent deburring processes. For Ground Bars Copper Bus Bars that need to be bent or punched, use a CNC punch or bending machine to process them. The bending radius should not be less than 1.5 times the material thickness to prevent micro-cracks on the copper surface.

 

In the surface treatment process, electro-tin plating, electro-nickel plating, chemical passivation or hot-dip tin processes are selected according to the final use environment. Among them, the electroplated tin layer needs to pass the adhesion test (cross-hatch method or tape peeling method) and thickness uniformity test (X-ray fluorescence thickness gauge, thickness tolerance ±1μm). Quality inspection covers dimensional tolerance (using a three-dimensional coordinate measuring instrument or laser distance meter), conductivity (eddy current conductometer or double bridge method, requiring ≥98% IACS), tensile strength (universal testing machine, typical value ≥240MPa), elongation (≥15%) and corrosion resistance verification. Corrosion resistance is measured through the neutral salt spray test (NSS). For outdoor or buried products, it is required that there is no red rust on the surface after passing the salt spray test for at least 72 hours. In addition, a contact resistance test will be conducted: two sections of copper grounding copper bars are tightened with standard bolts and then the resistance at the connection is measured. It is required to be no more than 1.2 times the resistance of the busbar itself of the same length. All inspection data are recorded to form a traceable quality report.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The terminal connection interface is the area where the copper ground copper bar is in direct contact with the external ground cable or equipment ground terminal. Its detailed design is crucial to the long-term stability of the contact resistance. The hole margin (the distance from the center of the hole to the edge of the busbar) is usually not less than 1.5 times the hole diameter to prevent edge tearing when tightening. For applications that require frequent plugging and unplugging or withstand vibration, the terminal interface will be countersunk or countersunk to allow the bolt heads or washers to sink into the busbar surface to increase the anti-loosening ability. Some high-end Wall Mounted Copper Ground Bar Kits have stainless steel nuts or copper nuts pre-riveted in the terminal connection area. There is no need to equip additional nuts and washers during on-site installation. You only need to crimp the ground cable terminals and screw the bolts directly, which greatly improves construction efficiency. The flatness of the terminal interface is required to be within 0.1mm. Any bulges or depressions will lead to reduced contact area and local overheating. In mass production, special inspection tools are used to check the terminal interface to ensure that the hole diameter and position size are all qualified.

 

The surface treatment layer of the copper grounding copper bar shows rich microstructural characteristics under the microscope. For bare copper busbars, the surface should have a uniform purple-red metallic luster, no oxidation stains, no oil stains, and no scratches deeper than 0.1mm. The uniform rolling texture of high-quality bare copper rows can be seen under a microscope with 50 times magnification, without pitting pits or inclusions. For Tinned Copper Ground Bar for Underground System, the microstructure of the tin plating layer is crucial. The tin layer obtained by the electroplating process has a fine columnar crystal structure with a thickness of 3–8 μm and low porosity (≤2 pores/cm²), which can effectively block the diffusion of chloride ions and oxygen. There is an extremely thin layer of copper-tin intermetallic compound (Cu₃Sn or Cu₆Sn₅) between the tin plating layer and the copper matrix, with a thickness of about 0.5–1μm. The continuity and density of this layer of compound determines the adhesion of the plating layer. The tin layer obtained by the hot-dip plating process is thicker (10-20μm), and the surface shows a typical corrugated solidification pattern. The grains are relatively coarse, but it has stronger corrosion resistance and is suitable for extreme buried environments. The adhesion of the tin-plated layer is verified through a bending test: bend the tin-plated copper bar 180°, and there should be no peeling or peeling of the coating at the bent part. For nickel plating, the thickness of the nickel layer is usually 2-5μm, with a silver-white semi-glossy appearance and a microhardness of up to 300-500HV. It is more wear-resistant than the tin layer and is suitable for Grounding Busbar Tmgb Copper that is frequently plugged and unplugged.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Based on the system short-circuit capacity, installation space and environmental level provided by the customer, we can provide a one-stop service from cross-section calculation, drawing to finished product delivery, ensuring that each Copper Earth Ground Bar meets the engineering requirements of low impedance, long life and high reliability grounding.