1. Purpose 2. SCOPE 3. Reference Standard or material 4. Material introduction 4.1 copper and copper alloy sheet 4.2 grade and status 4.3 mechanical properties 5 specification content 5.1 basic function description 5.2 technical requirements 6. Introduction to riveting 7. Inspection/test requirements 7.1 check the quality of the copper bar and its accessories, 7.2 inspection of the coating according to the technical requirements of the drawing 7.3 inspection of the LAP surface 7.4 corrosion test of the copper bar sample

1. Purpose 

The purpose of this code is to standardize the design of copper bar structure parts, and to guide the structural designer to select the form and material of copper bar correctly, ensure that the parts designed by designers have a better processing technology, speed up the processing schedule, reduce processing costs. At the same time guide the copper bar processing, inspection and acceptance.

2. SCOPE of application

Design, fabrication and inspection of copper bars.

3. references/standards or information

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Introduction of materials

4.1 there are two main types of copper and copper alloy sheet: Copper T2 and brass H62. Copper T2 is the most common pure copper, purple in appearance, also known as copper, has high conductivity and thermal conductivity, good corrosion resistance and formability, but much lower strength and hardness than brass, very expensive, mainly used for conducting electricity and heat, corrosion-resistant components, generally used in the power supply need to bear a large current parts. Brass H62, a high zinc brass, has high strength and cold, hot processing, easy to carry out various forms of forming and cutting processing. Mainly used for various deep drawing and bending parts, its electrical conductivity is not as good as copper, but it has higher strength and hardness, the price is also more moderate, in meeting the requirements of electrical conductivity, as far as possible to choose brass instead of copper, can greatly reduce the cost of materials. 4.2 pure copper of No. 2 copper, codenamed T2, commonly used for grade and condition copper plates; pure copper of No. 2 copper for copper bus bar, codenamed TM.

5. Standardize content

5.1 basic function description 5.1.1 to meet the need of electrical function, realize the transmission of current, voltage and electric signal, 5.1.2 to replace the large section conductor with Copper Bar, the craft request is low, easy to bend, easy to realize the connection; 5.1.3 small section conductors are replaced by copper bars, which are small in size, beautiful and easy to fix. 5.1.4 easy to connect when realizing current confluent connection and earthing function. 5.1.5 copper bars are directly connected to structural parts after machining, simplifying final assembly production. 5.2 technical requirements 5.2.1 General Design Requirements (1) to meet electrical performance requirements with suitable copper bars. (2) normal operation, temperature rise, environment and vibration during transportation of power supply and electrical products shall not cause abnormal change of copper bar connection. (3) the effect of thermal expansion and electrochemical corrosion on materials should be considered in structural design. (4) the connection between the copper bars shall ensure sufficient and lasting contact pressure to meet the requirements of low contact resistance and temperature rise, but shall not cause permanent deformation of the copper bars. 5.2.2 design selection (1) type, specification and standard number of copper busbar section shape a: thickness i.e. narrow side dimension MMB: Width i.e. wide side dimension: round corner or rounded edge

Such as: Narrow side for 10, wide side for 100 copper bus, hard state. The type of TMY-100X10 copper bus bar indicated in the material column of the drawing is shown in Table 1.

When the standard copper bus bar can not meet the design requirements, the pure copper plate, such as the pure copper plate parts with thickness of 3, in the material bar of the drawing, it is denoted as: T2Y-3.0(see GB2059-89)(2) basic state anneal. It is suitable to be fully annealed to obtain the minimum strength of pressure processed products. It is suitable to be cold processed or combined with incomplete annealing to obtain the standard mechanical properties of the products. (3) for the technical requirements of the material and processing of the bus-bar, the ? copper bus-bar shall be manufactured with copper ingots conforming to the requirements of GB468-82 with a resistivity of not more than 0.01774 ohm. No busbar with a diameter greater than 2.5 mm shall be used on the surface of the MM2/M?COPPER busbar where there are cracks, spots, pits and saltpeter deposits on the surface, buses with a depth greater than 0.15 mm shall not be made straight or re-bent after bending. Buses shall be made straight, levelled, and in the shear section, after drilling and punching, burr should be removed. All LAP surfaces of the bus should be flattened by a press to ensure good lap contact 5.2.3 basic data (1) specification and current carrying capacity of commonly used copper bus are shown in table 2.

Table 3 current carrying capacity of 2 ~ 3 copper busbars superimposed (maximum allowable temperature of copper busbars is 70 °C, ambient temperature is 25 °C)

The current carrying capacity of copper bar structure made of copper plate refers to the above table (2) the copper bar should be selected in consideration of rigidity; if multiple holes are made in the copper bar, the influence of the holes on the cross section of the copper bar should be considered, and the cross section of the copper bar should be increased appropriately. (3) depending on the width of the Copper Bar, the requirements for determining the overlap type and the drilling location are shown in Table 4. Table 4 empirical data from practice to standardize structural design, determine the lap form of copper bars, the size of holes and the size of hole position

(5) when the bus bar is twisted 90 ° , the total length of the twisted part is not less than 2.5 times of the bus bar width (not recommended) . (6) the inner bending angle of the copper bar shall be marked on the drawing. (7) the marking of copper platen should be marked, and the tolerance of imprinting position should be within ± 5mm. (8) copper bars are usually chamfered R2, special case marked on drawing

6. Introduction to riveting

The copper bars can be connected directly by tapping, riveting nuts or through bare holes. (depending on the thickness of the plate)

In the use of copper row rivet nut, in order to connect firmly and reliably, generally choose hexagon rivet nut, the supplier will choose the nut according to the thickness of copper row to choose suitable thick nuts (rivet thick copper row nut is custom-made) . Screws are sometimes riveted to the copper bars, usually using high-strength (HFH) rivets.

7. inspection/test requirements

Check the quality of the copper bar and its accessories and the surface quality according to the technical requirements of the drawing 7.1.1. Copper Bar should choose high-quality materials, material surface defects, uniform color 7.1.2. Surface protection must be carried out to avoid damage to the surface, assembly personnel must wear gloves to prevent the surface to leave fingerprints, stains. 7.1.3. After the copper bar is bent, there should be no obvious crack at the bend. 7.1.4. It is strictly forbidden to fill the same size copper material in the position of the round hole when the copper row is punched wrongly. 7.1.5. The copper bus-bar shall be straightened. The bending degree of the broad surface of the copper bus-bar shall not be more than 2 mm per meter and the bending degree of the narrow surface shall not be more than 3 mm per meter. 7.2 coating inspection main application coating: Bright Nickel, bright tin coating performance, characteristics nickel plating (recommended use)1. The stability of nickel coating in air is very high. Because of the strong passivation ability of nickel, a very thin passivation film can be quickly formed on the surface, which can resist the corrosion of atmosphere, alkali and some acids. 2. Can Be used as a protective decorative coating 3. Uniform thickness of tin plating with corrosion resistance, Color Change, non-toxic, easy to weld, soft and malleable, but easy to scratch, should not touch the sweat, should not be stored in a damp place, otherwise easy to change color. 7.2.1 the drawings for the representation of coatings are required to be marked as: NICKEL-PLATED CU/NI15B TIN-PLATED CU/SN15B. Notes: (1) Cu/-indicates the substrate is copper or copper alloy (2) the chemical symbol Ni, indicates the nickel coating; Sn, indicates the number behind the tin coating (3) Ni and SN, represents the minimum thickness of the coating, Um (4) according to the conditions of use for outdoor general atmospheric environment, and the copper layer as the bottom of the coating of the minimum thickness of 15um (5) after the number of lowercase letters, indicating type of coating: bfoshan means a coating deposited under full bright electroplating specifications. 7.2.2 treatment of copper substrate prior to electroplating the surface condition of the substrate prior to electroplating shall be specified or agreed upon by the producer and the purchaser. The main surface of the work piece is then inspected by the supplier for obvious surface defects, such as air holes, cracks and undesirable overlays, or any other defect detrimental to the final finish, check the flatness of the copper bar surface, especially of the lap. All defects shall be brought to the attention of the purchaser prior to any treatment. 7.2.3 no obvious plating defects such as bubbling, pitting, porosity, peeling, coarseness, cracks, leakages, stains or poor colour should be found on the surface of the surface which has not been plated in any way. The unavoidable marks on the surface and their locations shall also be specified by the demander. A all parts shall be visually inspected according to GB5926-86. B Nickel coating should be bright with a soft light yellow silvery white; tin coating should be bright light gray. C coating crystallization should be uniform, fine, smooth, continuous. D on The nonprincipal surface of the part, the following defects are allowed: 1) small and few jig marks (jig marks are less than 1.1 MM2) ; 2) the nickel coating is partially fogged, and the tin coating is slightly watermarked or shaded (fogged, watermarked or shaded area is less than 10.10 MM2) . Do Not Allow: 3) deposits with spots, black spots, scorch, roughness, pinhole, pitting, delamination, blistering, peeling, peeling: 4) Dendrite, sponge and striated deposits; 5) locally free deposits (except in blind holes and in holes deeper than diameter) ; 7.2.4 measurement of coating thickness measurement of coating thickness at any location on the main surface designated by the demander, the measurement error must be less than 10% . (1). Thickness gauge method (film thickness gauge)(2). Direct measurement to determine a reference point, measuring the thickness of the point before and after the coating thickness can be obtained. This can be done with ordinary measuring tools such as micrometers, depth gauges, etc. . 7.2.5 bond strength test the bond strength of the coating shall be performed according to the file test specified in GB5270 or one of the thermal shock test methods. The coating shall not be separated from the substrate after the test. 7.3 The lap joint is inspected to check the reliability of the contact between the electrical connections. The gap size or the temperature at the connections of the copper bars can be checked. 7.3.1 method of inspection of copper bar joints (1). Insert the 0.03 mm plug gauge into the gap of the LAP surface of the copper bar. Insert from four directions. The sum of the maximum depth of the four directions of the plug gauge is not more than 12.5% of the lap circumference. The length of the insertion of a single directional plug gauge is not more than 25% of the lap length at the point

L 1≤ A 25% , l ≤3≤ a 25% , l 2≤ b 25% , l 4≤ B 25% , l 1, L 2, L 3, l 4: Maximum depth of insertion of feeler gauge in the insertion direction 1,2,3,4. A: LAP WIDTH OF COPPER BAR 1. B: Lap Width of Copper Bar 2. (2). The contact pressure of detachable joint is not less than 10 MPA. (3). The contact resistance at the connection shall not be greater than the resistance of a single copper bar of the same length, or the voltage drop shall not be greater than 7 MV. (4). If the temperature at the joint is not higher than 70 °C. 7.3.2 and the natural frequency of 20ー25 Hz, the acceleration of 9.8 m/s 2 is applied for 6 h, no deformation and looseness, and the contact resistance and temperature rise remain unchanged. 7.4 The anticorrosion test of copper sheet is usually carried out by examining the thickness of the coating, which can be measured by thickness meter.

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