Copper Bar, also known as copper bus bar or copper bus bar, is made of copper material, long Rectangular or chamfered rectangular conductors (now generally copper fillets to avoid tip discharge) that act as current carriers and electrical connections in a circuit. Copper bars are widely used in electrical equipment, especially in complete sets of power distribution equipment.

1. Process preparation

(1) according to the design drawings and production task list, consider the best solution. 

(2) check the electrical components, accessories model specifications are in line with the drawing and bill of materials requirements, product license, certificate of compliance is complete.

2.Selection of bus bar

(1) the specifications and material of the main bus according to the design drawings, branch bus material without special requirements and the same as the main loop bus. 

(2)Branch Circuit Bus (wire) selection, according to the diagram marked wire diameter selection, if not marked by the circuit breaker current selection.

 (3 )When the bus bar is selected for the main circuit or the branch circuit, the section size not less than the current carrying capacity is selected according to the rated current in tables 2 and 3. 

(4) The grounding Busbar (PE) of the low-voltage distribution equipment shall meet the requirements of Table 1.

5, high-voltage distribution equipment grounding busbar cross-section should not be less than 30 square mm, not less than 4 square mm. 6, the surface of the bus bar should be smooth, smooth, no cracks, no inclusions.

3.Technical requirements

(1)The creepage distance shall not be less than the values given in Table 5, table 6 and Table 7 for electrical components, live parts and the electrical clearance between bus bars. In order to improve the safety performance of the products and facilitate the construction, the electrical clearance of the low-voltage switchgear in our factory should not be less than 15mm, the creepage distance should not be less than 20mm, and in special cases, the value in table 6 and Table 7.

(2)The color and phase sequence of bus bar shall be in accordance with Table 8

(3)The contact of the BUSBAR shall be closely connected, and the fastening force of the connecting bolt shall be in accordance with Table 9

4.Production of bus bar

MANUFACTURE OF COPPER BUSBAR: 

(1) The direction and size of Busbar shall be determined by the builder. The same form of switchgear wiring shall be the same.

 (2) The bus bar shall be straightened, the bus bar shall be straightened by the bus bar rolling mill, and the bus bar shall be locally adjusted by the Wooden Mallet. The Vertical Bend (Side Bend) shall not be more than 2 MM/M, the flat bend (Wide Bend) shall not be more than 3 MM/M, and the section shall be level off, there shall be no burrs or deformations affecting the quality of the cut. 

(3)According to the position of the components and the selected direction, make the sample of bus bar with hard wire or other material, get the most ideal bending form, according to its developing size, use the special punching and cutting material of bus bar processing machine, and draw the bending line. 

(4)the surface of the bus bar should be smooth and smooth, should not have cracks, wrinkles, inclusions and deformation and distortion phenomenon. 5. The bus bar bending type should be bent according to the need, there are three basic bending types, the bending type and the minimum bending radius;

(6) Busbar should be less right-angle bending, bending shall not have cracks and significant wrinkles, not allowed to have been bent busbar in the original bending and reverse bending. 

(7)The bending degree of multiple busbars shall be the same, and there shall be a gap of the same thickness between busbars. (special circumstances apply). 

(8)There should be a distance of 10 mm between the bus bend and the overlap, and a distance of more than or equal to 20 mm from the support point at the bus bend or the bus overlap (except limited by space) .

5.Punching (drilling)

(1)first the bus needs to punch the location of the center line, and punch a hole with the punch.

 (2)The diameter of the hole of the busbar connecting head should be larger than 0.5 ~ 1mm of the bolt diameter. Punch (drill) hole should be vertical, not askew, between the hole center distance error should not be greater than 0.5 mm. 3. The number and size of holes punched (drilled) by copper busbar with different widths are shown in table 12.

(4)The burr after piercing (drilling) should not be ground by file, and should be removed by trance drilling, the depth should not be more than 0.8 mm. 

(5) The contact surface of Busbar should be treated by embossing and leveling die. After treatment, there should be no oxide film on the contact surface. After processing, the reduced value of the busbar should not exceed 3% of the original section. 

(6)When the Busbar is fixed on the insulator, the busbar opening shall be carried out as shown in the following figure.

6.Connection between bus and electrical components

 (1)Direct Connection Requirements: When the terminal of the component is flat, the bus connection can be directly bolted as shown in figure, but the fastener must be steel.

(2)when the component joint is a screw, the bus can be directly connected to the screw, as shown below, in order to prevent loosening, to add a lock nut, in between the lock nut shall not add a Washer.

7.a bus wiring inspection bus installed after there should be no stress, 

open inspection should meet table 13 requirements

8. busbar heat shrinkable 

(1)three-phase Busbar in combined substation should be heat shrinkable. 

(2)The color of Busbar Heat shrinkable tube shall conform to table 8. 3, according to the specification of the bus bar to select the appropriate heat shrinkable tube, and according to the required size under the wallpaper knife. 4, the heat shrinkable tube set in the bus bar, with hot hair dryer heating, until the Heat shrinkable tube set in the bus bar so far. 5. The heat shrinkable tube should be flat and wrinkle-free. 6. The ground wire and the ground wire in the equipment can not be heat-shrinkable, but the corresponding earthing and the ground wire signs should be pasted, 20mm signs should be pasted on the bus wire less than 40mm in width and 30MM signs should be pasted on the bus wire more than 40mm in width. The assembly of the bus Bar 1, bus bar and bus bar, bus bar and electrical components connection, all use through bolt fastening, through bolt fastening force should comply with table 9. 2. The overlapping contact surface of the bus bar should be kept clean. (if special requirements can be coated with electric compound grease)

(3)When the bus bar is placed, the bolts should be threaded from bottom to top. In other cases, the nuts should be placed on the maintenance side, at this point the bolt length should be exposed nut 2 ~ 5 buckles. 

(4)WASHERS shall be used on both sides of the bolt, the washers of the adjacent bolt shall have a clear distance of 3mm, and the nut side shall be provided with Spring washers or locking nuts. 

(5)The Bolt should bear even force, should not make the terminal of the electric device subjected to additional stress. 

(6)There should be no stress after the BUSBAR is installed. 

(7)busbar connections can be protected by special insulated bushing. 

Source: electricity