Low-voltage switchgear is suitable for power plant, petroleum, chemical industry, metallurgy, textile, high-rise building and other industries, and is used for power transmission, distribution and electric energy conversion. The product conforms to the standard of GB725 1. 1-2005 Low-voltage Switchgear (IEC 60439- 1. 1999). Low-voltage switchgear is listed in the catalogue of compulsory certification products with 3C certification.
Introduction of switchgear
GCS low-voltage draw-out switchgear
GCS low-voltage switchgear
GCK pull-out switchgear
GGD low-voltage fixed switchgear
Assembled low-voltage switchgear
MNSC low-voltage draw-out switchgear
MS low-voltage draw-out switchgear
GCS low-voltage draw-out switchgear
MNSQH draw-out low-voltage switchgear
GCS low-voltage draw-out switchgear GCK(L) low-voltage switchgear
Basic electricity
1, and the rated isolation voltage is 690v.
2. The rated working voltage is 380V and 660V.
3. The rated frequency is 50Hz.
4. Rated working current:
The rated current of the horizontal bus is 630-6300A.
Rated current of vertical bus is 630- 1600A.
5, rated short-term withstand current
The rated peak withstand current (IS) is 30-80KA.
The rated short-term withstand current (IS) is) 30-80KA.
6. Rated withstand peak current
Horizontal bus (main bus) 63- 176KA
Vertical bus (branch bus) 63- 176KA
Conditions of use
* The ambient air temperature shall not exceed +40℃ and not lower than -5℃, and the average temperature within 24 hours shall not exceed +35℃.
* The air is fresh. When the highest temperature is +40℃, its relative humidity shall not exceed 50%. At lower temperature, larger relative humidity is allowed.
* Level III pollution.
Drawer type low-voltage switchgear
* The altitude of the installation site shall not exceed 2000m.
* Special conditions of use shall be negotiated separately when ordering.
classify
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.
Slave connection mode
(1) welding type:
Its advantages are convenient processing, firmness and reliability; Disadvantages are large error, easy deformation, difficult adjustment, unsightly appearance, and the workpiece cannot be pre-plated. In addition, there are certain requirements for welding clips:
(1) has good rigidity and will not be affected by workpiece deformation;
(2) The external dimension is slightly larger than the nominal dimension of the workpiece, which can offset the influence of shrinkage after welding;
③ The operation is stable, simple and convenient, and the rotating mechanism is minimized to avoid jamming;
(4) In order to prevent welding corrosion and facilitate maintenance and adjustment, it is necessary to select a good workpiece support and add anti-welding corrosion pads on the support.
The deformation of the workpiece after welding is due to the stress caused by the expansion and extrusion of heated molecules at the welding site, which cannot be reset after cooling. In order to overcome the influence of deformation, the forming process must be considered. The methods of plastic surgery generally include:
(1) Predict the deformation range of the workpiece through experiments, and force the workpiece to deform in the opposite direction before welding to reach the predetermined size after welding;
(2) Post-welding correction method;
(3) Knocking and extruding the relatively contracted part after welding to obtain stress balance;
(4) heating the relatively loose convex part after welding to make it reach the same shrinkage rate as the welded part;
⑤ When necessary, heat treat the whole part.
In addition, the selection of welding points, weld direction, welding sequence and spot welding positioning all have certain effects on post-welding deformation, which can be reduced if handled properly, but it depends on the specific situation.
(2) Fastener connection:
Its advantages are that it is suitable for pre-plating of workpieces, easy to change and adjust, easy to beautify, standardized parts design, pre-production and pre-inventory, and small error in frame shape and size. The disadvantage is that it is not as firm as welding, requires high precision of parts and components, and the processing cost is relatively rising. Fasteners are generally standard parts, mainly including conventional screws, nuts and rivets, rivets, pre-tightening fine-tuning clamping nuts and pre-tightening nuts, as well as self-tapping screws. There are also special fastening screws (for example, most low-voltage cabinets imported from abroad use special fastening screws).
Process characteristics: fixture forming, fixture positioning and pressure cleaning machine as required; Riveting generally requires drilling, and the pre-plating part should prevent the coating from being damaged; For parts processed by precision machining centers or special equipment, if there is a slight gap between each connecting aperture and the diameter of the fastener, they can be assembled without fixture and molded at one time; The fastening of the guiding and positioning parts should be first positioned with special measuring tools, and then detected with standard tools.
Product characteristics
1. reasonable design: according to the characteristics of various switching appliances such as escape exits and production plans, the unit is designed and combined into functional units.
2. Universal structure and flexible assembly: C-shaped profiles meet the requirements of various structural forms, I- browsing levels and surrounding conditions.
3. The standard module can be composed of standard unit module structures such as protection, operation, conversion and control, and any group of skins can be selected.
4. Safety protection: inter-regional isolation and mutual isolation of incoming and outgoing lines of functional units are adopted to effectively enhance safety protection performance.
5. Technical parameters: The main technical parameters are at the international leading level.
Related standards
SJ/T 31401-1994 | Requirements and inspection and evaluation methods of high-voltage switchgear.
DL/T 79 1-200 1| Guide for Selection of Indoor AC Inflatable Switchgear
Equipment orders specification of DL 404- 199 1| indoor AC high-voltage switch.
DL/T 404- 1997| equipment orders Technical Specification for Indoor AC High Voltage Switch
DL/T 539- 1993| Technical requirements for dew condensation and contamination test of indoor AC high-voltage switchgear and components.
Tb/t 2010-1987 | 27.5 kv AC electrified railway switchgear technical requirements.
DL/T 404-2005| equipment orders Technical Specification for Indoor AC High Voltage Switch