n the design of low voltage copper bar, the following aspects should be considered: 1. Notice of Horizontal busbar length calculation, 3. Notice of incoming branch busbar length calculation, 4. Notice of Frame Circuit Breaker Cabinet busbar calculation, how to choose Vertical Busbar? How to calculate the length of the copper bar of the drawer and how to choose the copper bar of the capacitor cabinet? 1. Horizontal busbar length calculation horizontal busbar length calculation, in addition to the width of the cabinet, but also consider the following points: 1, if there is a request to busbar top 200, in fact, the total length of copper bar is not only 200, also include the cabinet and the main bus overlap part, the normal length should be calculated by 400. 2. The length of the horizontal copper bar of the upper drive line is the cabinet width. This calculation is only applicable to the upper drive line. There are horizontal busbars before and after the side entry line, which should be taken into account. In principle to increase at least half the width of the main bar, in order to prevent the occurrence of less calculation of copper bar, it is recommended to increase the main bar bar of a counter (as shown in the following figure) .

The length calculation of the branch busbar of the incoming line (the side busbar of the Copper Bar) shows that the increase of the main busbar of the cabinet width is accounted for in the branch busbar of the incoming line. The length of the copper bar below does not include the main busbar.

Zero row for the top of the cabinet into the side or the use of three-phase four-wire, three-phase five-wire busbar bridge (slot) into the line, the need to increase the root under the zero row quote. If it is the introduction of three-phase five-line, it is necessary to increase the quote below the row: that is, the row also need to branch about 2.3 meters.

3, frame breaker busbar length calculation points for attention: the calculation mode of the copper bar of the mixed cabinet should be the amount of a frame breaker + a drawer cabinet, not just according to the amount of a single frame or a single drawer.

The metering chamber is usually 0.2 m higher than the normal low-pressure instrument chamber. The length of the copper bar is increased by 0.4 m per phase. The plan of the knife melting switch above the circuit breaker should also consider the increase of the total length of the copper bar by 0.4 meters.

The length of the copper bar corresponding to each frame of the cabinet with multiple frame outgoing wires is not consistent.

Four, drawer cabinet vertical bus specification and length of the calculation method: a complete set of equipment or a part of a complete set of equipment (such as a frame unit) has a number of main circuits, the rated dispersion factor is the ratio of the sum of the large current passed by all the main circuits at any one time to the sum of the rated current of all the main circuits of the whole equipment or selected part of the whole equipment

Take an outlet cabinet as an example: there are 7 plastic shells in the outlet cabinet, the total rated current is 1200A, then the dispersion Coefficient is 1200 * 0.7 = 840a

When the drawer is full, the vertical single-phase length of the cabinet is 1955, the price is quoted according to 2000mm, the average single-phase length of the overlap row is 500(bus frame front)400(bus frame back) , the price is quoted according to 500mm, the vertical zero-row length of the cabinet is 12.00 + 0.300 + 0.300 = 1.8 meters

Description: Beijing area requirements must have a vertical row and Vertical Zero side-by-side arrangement, when the Beijing project to be quoted this copper row, length and zero row consistent, according to GB7251.1 specifications of the relevant requirements (see the next page) . The section of the protective line (PE) shall be executed in the following table when no special requirements are required

Note: 1. If there is any requirement in the PE arrangement drawing of the master row, it should be carried out according to the specification in the drawing in principle, if there is no requirement, it should be carried out according to the above table; if the scheme can be optimized, it should be carried out according to the above table. 2. The vertical zero row reference object is the vertical row. The total length of the copper bar inside the drawer is 0.24 + 0.32 + 0.32 + 0.5 + 0.2 + 0.37 + 0.4 + 0.4 + 0.2 * 2 = 3.15 meters. The price can be quoted by 3.5 meters

Calculation of the length of copper row in the capacitor cabinet: There is a concept of three-phase horizontal row in the capacitor cabinet, the three-phase horizontal row is usually the same as the width of the cabinet. The width of a capacitor cabinet is usually 800,1000,1200. At the conventional width of 800, the existing standard is 2 meters per phase (vertical + horizontal) . If the cabinet width is widened, please make up the corresponding length of copper bar. That is, 1,000 width plus 0.2 m, and 1,200 width plus 0.4 m.

There are other cabinets, such as double power cabinets, bus cabinets, cable into the cabinet type of copper discharge capacity can refer to the annex "low-voltage copper discharge capacity" shown in the document.

Source: Power Engineering Technology