Divided from the structural mode
(1) fixed:
It can meet the requirement that all electrical components are reliably fixed in the cabinet to determine the position. The appearance of cabinets is generally cubic, such as screen type and box type. There are also prismatic bodies such as terraces. This kind of cabinets are arranged in rows.
In order to ensure the size of the cabinet, the components are often combined step by step. Generally, two pieces or left and right sides are formed first, and then the cabinet is formed, or the appearance requirements are met first, and then some branches in the cabinet are connected in turn. The length of the parts that make up each side of the cabinet must be correct (the tolerance is negative) to ensure the geometric dimensions and overall appearance requirements of all aspects. For both sides of the cabinet, due to the need of arrangement, there should be no uplift in the middle.
In addition, from the installation point of view, the bottom surface should not be sunken. In arrangement and installation, foundation leveling is the premise, but there is a certain error between flatness and cabinet itself. When arranging, we should try our best to offset the lateral differences, rather than accumulate the differences, because the accumulation of differences will cause the cabinet deformation, affect the bus connection, produce eccentric installation of components, stress concentration, and even affect the service life of electrical appliances. Therefore, in the layout, the highest point of the foundation should be taken as the installation reference point, and then it should be gradually raised and expanded. When the bottom roughness is ideal and predictable, it can also be extended from the middle to both sides to make the cumulative difference evenly distributed.
In order to facilitate adjustment and offset tolerance accumulation, the cabinet width tolerance is negative. After all the components of the cabinet are assembled, they should be reformed as needed to meet the shape, position and size requirements of each part. When manufacturing shaped or large quantities of cabinets, we should give full consideration to the use of fixtures to ensure the correct and unified structure. The datum plane of fixture should be taken from the bottom, and the layout of positioning blocks in fixture should be based on the principle of convenient removal. For the cabinet door, it is easily affected by transportation and installation, and it is generally adjusted uniformly during installation.
(2) Pull-out:
The drawout type consists of a fixed cabinet and a movable device with switches and other main electrical components. Movable parts should be portable when moving, and the positioning should be reliable after moving in, and drawers of the same model and specification can be reliably interchanged. The processing method of drawer cabinet is basically similar to that of fixed cabinet. However, due to the exchange requirements, the accuracy of the cabinet must be improved and the relevant parts of the structure should be adjusted enough. As for the movable device, it should not only be able to move and replace, but also bear the main parts reliably, so it should have high mechanical strength and accuracy, and the relevant parts should be adjusted enough.
The technological characteristics of manufacturing drawer-type low-voltage cabinet are as follows: (1) There should be a unified reference standard for fixed and movable parts; (2) Relevant parts must be adjusted to the best position, and special standard tooling, including standard cabinets and standard drawers, should be used during adjustment; (3) The error of key dimensions cannot be out of tolerance; (4) The interchangeability of drawers of the same type and specification shall be reliable.