Copper industry knowledge: copper bar surface treatment and related knowledge introduction

What is copper bar? What is the function of copper bar? What is the surface treatment method of copper bar? Is there any introduction to copper bar related knowledge? First, let's understand the overview of copper bar: copper bar is a large current conductive product, suitable for high and low voltage electrical appliances, switch contacts, power distribution equipment, bus duct and other electrical engineering, and is also widely used in metal smelting, electrochemical electroplating, chemical caustic soda and other super-current electrolytic smelting engineering. We supply electrician copper bar has the advantages of low resistivity and large bending degree.

Copper bar is also called copper bus bar, copper bus bar or copper bus bar and grounding copper bar. It is made of copper material and has a rectangular section or chamfered (rounded) rectangular long conductor. It is made of aluminum material and is called aluminum bar. It plays the role of transporting current and connecting electrical equipment in the circuit.

Because copper has better conductivity than aluminum, copper bars have been widely used in electrical equipment, especially in complete sets of power distribution devices. In general, copper bars are used for U, V, W-phase bus bars and PE bus bars in power distribution cabinets. Copper bars are generally marked with phase color letters or painted with phase color paint, U-phase copper bars are painted with "yellow" color and V-phase copper bars are painted with "green" color, W-phase copper bar is coated with "red" color, and PE bus bar copper bar is coated with "yellow and green" double color.

Introduction to copper row related knowledge-effect of copper row tin plating on copper row conductivity:

Tin plating on the surface of the copper bar has the functions of preventing oxidation of the copper bar and improving the connection contact surface of the copper bar. Moreover, the metal tin and the copper bonding layer will form an alloy, which enhances the adhesion of the copper bar coating. In addition, the conductivity of the metal tin is not bad. Good compactness, high smoothness, and enhanced wear resistance of the plated parts.

Copper bar related knowledge introduction-copper bar surface tin plating purposes:

(1) the manufacture of tin cans: due to the non-toxic tin coating, a large number of objects in contact with food and beverages, the largest use is the manufacture of tin cans, other such as kitchen utensils, food knives and forks, ovens and so on.

(2) electrical and electronic industry: because tin is easy to weld, good conductivity, widely used in electrical and electronic parts need to be welded.

(3) Copper wire: improve the weldability of copper wire and the barrier between copper wire and insulation.

(4) activity: because of tin soft, can prevent scratches, as a solid lubricant.

(5) to prevent steel nitriding.

Introduction to copper bar related knowledge-copper bar surface treatment items:

1. To prevent the external environment from corroding the copper bar, the measures taken are: nickel plating, zinc plating, tin lining, silver plating, painting, protective casing, etc.

2. To increase the insulation performance and prevent touching the charged body, the measures taken are: sleeve insulation sleeve (cold/heat shrinkable insulation sleeve) and sleeve joint sleeve.

3. Increase the conductivity. Copper is used for conductivity. The strength of conductivity is: gold, silver, copper, aluminum .... Due to alternating current, most of the current goes to the surface. If the copper body is not plated with gold or silver, it is best not to plate. Then why tin plating, nickel plating, mainly anti-corrosion. Therefore, in order to keep the environment forever, it is best not to plate anything, except gold and silver. After plating, the conductivity becomes worse.

4. Increase the heat dissipation performance, the main measure is black paint.

Copper bar related knowledge introduction-copper bar surface treatment method process:

1. Copper bar painting

This process belongs to the elimination of backward technology, is rarely used. Process: The bus bars of three-phase AC circuits are all painted in black, and color codes are pasted on conspicuous places. Phase A is yellow, phase B is green, phase C is red, neutral line or neutral line is painted in light blue, and grounding line for safety is painted in alternating yellow and green colors. Those who cannot distinguish polarity and phase sequence are painted in white.

2. Copper row tin plating

Advantages: mature process. Short operating cycle, commonly used. Disadvantages: The surface is dark over time and cannot be done by human hands. Not environmentally friendly!

Process flow: pretreatment such as surface polishing and degreasing → pure water washing → tap water washing of high Pb-Sn alloy plating → pure water washing → tin plating → tap water spraying → neutralization (Na2HPO4 Na3PO4)→ tap water spraying → stearic acid soaking → tap water spraying → hot pure water dipping → drying.

3. Protective agent for copper bar coating

Advantages: maintain the copper bar primary color, slightly lower cost than tin plating. Disadvantages: long operation cycle.

Process flow: pre-polishing treatment → pure water washing → pickling passivation workpiece → drying moisture → JLR-510 protection treatment → flowing water washing → hot water soaking (about 100 ℃, to be used for heating the workpiece to volatilize or dry the moisture by itself) → drying → packaging closing.

Copper bar related knowledge introduction-copper bar installation requirements:

1. The copper bar assembly must wear gloves to prevent fingerprints and stains on the surface.

3. Fasteners for copper bar connection shall be galvanized bolts/screws, nuts and washers in accordance with national standards.

3. The length of the combined screw should consider that the screw thread can be exposed to 2~5mm outside the nut after the screw is fastened, and the length of the hexagon head bolt/semi-round head square neck bolt should consider that the screw thread can be exposed to 5~8mm outside the nut after the bolt is fastened, and should not be too long or too short.

4. The bolt penetration direction is generally from bottom to top, from back to front, from left to right, and try to achieve unity. When the copper bar is placed horizontally, the bolts and nuts for connection shall be tightened from bottom to top. In other cases, the nuts shall be installed on the side convenient for maintenance.

5. There should be flat washers on both sides of the connecting copper bolts, and spring washers or lock washers should be added on the nut side.. Adjacent bolt washers should have a clear distance of more than 3mm to prevent heating of the magnetic circuit.

6. Under normal circumstances, it is not suitable to overlap three copper bars in one place, according to the requirements of design and process documents.

7. The copper bar contact surface shall be tightly connected, the connecting bolts shall be tightened with torque wrench for confirmation and marking, and the connecting combination screws shall be tightened with torque batch for confirmation and marking. The tightening torque value shall conform to the provisions of the Thread Fastening Process Specification.

8, copper bar installation should be smooth and beautiful, and copper bar installation: horizontal section: the height error of the two support points is not more than 3mm, the total length is not more than 10mm. Vertical section: the vertical error of the two support points is not more than 2mm, and the total length is not more than 5mm. Spacing: The spacing of parallel parts shall be uniform and the error shall not be greater than 5mm,

9. When more than two rectangular copper bars are connected in parallel, the gap between the parallel copper bars shall not be less than the thickness for heat dissipation.

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