The differences between the fixed type and withdrawable type of LV switchgear

BOKR ELEC company is a manufacturer specializing in MV&LV voltage switchgear assemblies. Customers often ask about the differences between fixed switchgear and drawout type switchgear. Now let's talk about the difference between them.

Fixed Type Switchgear

The utility model can satisfy the fixed position of each electrical component in the cabinet body reliably. The cabinet is usually cubic in shape, such as screen, box, etc. There are also prism, such as desktop, etc. This kind of cabinet is arranged in a single row.

In order to ensure the size and shape of cabinet, it is often adopted that each component is combined step by step. Generally, two pieces or left and right sides are formed first, then the cabinet body is formed, or the cabinet body is first satisfied with the shape requirements, and then the internal parts of the cabinet are connected sequentially. The lengths of the components that make up the edges of the cabinet must be correct (the tolerance is negative), so as to ensure the geometric dimensions of all aspects and the overall shape requirements. For both sides of the cabinet, there should be no uplift in the middle because of the need of arrangement.

In addition, from the installation point of view, there should be no subsidence at the bottom. In the arrangement and installation, the foundation leveling is a prerequisite, but there are some errors in the dryness and cabinet itself. In the arrangement, the lateral difference should be offset as far as possible, rather than the accumulation of the difference, because the accumulation of the difference will cause cabinet deformation, affect bus connection and assembly installation, stress concentration, and even affect the life of electrical appliances. Therefore, when arranging, it is appropriate to use the highest point of the foundation as the reference point for installation, and then gradually pad the positive expansion. Under the condition of ideal and predictable bottom dryness, it is also possible to adopt the expansion mode from the middle to both sides to make the accumulated difference evenly distributed.

In order to adjust easily and offset the accumulation of tolerances, the width tolerances of cabinets are negative. After each component combination of the cabinet is completed, it should be shaped as necessary to meet the requirements of the shape, position and size of each part. The fixture should be used to ensure the correct unification of the structure, the base plane of the fixture should be taken as the proper bottom surface, and the locating blocks in the fixture should be arranged according to the convenience of taking out the work. The external doors of the cabinet are easily affected by transportation and installation. Generally, the fixture should be adjusted uniformly during installation.

Withdrawable switchgear

Draw-out type is composed of fixed cabinet body and movable device with switch and other main electrical components. The movable part should be portable when it is transferred, and the positioning after it is moved should be reliable. The drawers of the same type and specification can be interchanged reliably. The processing method of the cabinet body part in the draw-out type is basically similar to that of the fixed cabinet body in the fixed type. However, due to the interchange requirement, the accuracy of cabinet body must be improved, and the relevant parts of the structure should have enough adjustment. As for the movable parts, they should be able to be replaced and the main components should be loaded reliably. Therefore, they should have higher mechanical strength and accuracy, and the relevant parts should have enough adjustment.

Significant advantage: when a outgoing load is failure and do not need to be like fixed type that must be disconnected from the power supply of the entire cabinet to repair, as long as the withdrawable switchgear pull out the faulted drawer unit for maintenance only, and it does not affect the normal operation for other loads.