Low-voltage complete switchgear

◆Main Circuit Scheme
The main circuit of the GGD cabinet is designed with 129 schemes and a total of 298 specifications (excluding schemes and specifications derived from functional changes in auxiliary circuits and variations in control voltage). Among them:
GGD1 type: 49 schemes, 123 specifications; GGD2 type: 53 schemes, 107 specifications; GGD3 type: 27 schemes, 68 specifications.
The main circuit schemes were selected based on feedback from numerous design and user departments, with additional schemes included to meet the needs of power plants. The rated current has been increased to 3200A, making it suitable for distribution transformers up to 2000kVA. Additionally, to accommodate reactive power compensation requirements, GGJ1-GGJ2 capacitor compensation cabinets have been designed, featuring 4 main circuit schemes and a total of 12 specifications.
◆Auxiliary Circuit Scheme
The auxiliary circuit design is divided into two parts: power supply and consumption schemes, and power plant schemes. The GGD cabinet provides ample space for the installation of secondary components.
◆Selection of Electrical Components
◇The GGD cabinet primarily utilizes well-established electrical components that are already mass-produced domestically, such as ME, DW15, DW17, DW45, CM1, NM1, etc. At the same time, based on principles of economy and rationality,
some usable older products like DZ20 are retained, provided feasibility is fully considered. Outdated products are not selected.
◇The HD13BX and HS13BX rotary-operated knife switches are specialized components designed to meet the unique structural requirements of the GGD cabinet. They modify the operating mechanism while retaining the advantages of older products, representing an innovative type of electrical component.
◇If design departments opt for newer electrical components with superior performance and advanced technology based on user needs, the GGD cabinet's flexible installation design generally avoids manufacturing and installation difficulties due to component updates.
◇To further enhance the dynamic stability of the main circuit, the GGD cabinet is equipped with specialized ZMJ-type combined busbar clamps and insulated supports. The busbar clamps are thermoformed from high-strength, high-flame-retardant PPO alloy material, offering high insulation strength, excellent self-extinguishing properties, and a unique structure. They can be easily assembled into single or double busbar clamps by adjusting modular spacers. The insulated supports feature a sleeve-type molded structure, providing low cost and high strength, addressing the insufficient creepage distance issues of older products.

>>Structural Overview

◇The cabinet body of the GGD-type AC low-voltage distribution cabinet adopts a universal cabinet design. The frame is partially welded and assembled from 8MF cold-formed steel sections, with frame parts and specialized matching components supplied by designated profile manufacturers to ensure precision and quality.
Components of the universal cabinet are designed based on modular principles, featuring 20-module mounting holes. The high degree of universality allows for pre-production in factories, shortening manufacturing cycles and improving efficiency. ◇The GGD cabinet design fully considers heat dissipation during operation. Both the top and bottom of the cabinet feature varying numbers of ventilation slots. When electrical components generate heat, the warm air rises and is expelled through the top slots, while cool air continuously enters through the bottom slots, creating a natural airflow channel from bottom to top within the sealed cabinet, achieving effective heat dissipation.
◇In accordance with modern industrial product design requirements, the GGD cabinet uses the golden ratio to design its external form and segmentation dimensions, resulting in an aesthetically pleasing and modern appearance.
◇The cabinet doors are connected to the frame via pivot hinges, allowing easy installation and removal. The folded edges of the doors are embedded with U-shaped rubber-plastic strips. When closed, the strips undergo a certain compression, preventing direct impact between the door and the frame and enhancing the door's protection rating.
◇The instrument door, equipped with electrical components, is connected to the frame using multi-strand flexible copper wires. Mounting parts inside the cabinet are connected to the frame with knurled screws, forming a complete grounding protection circuit.
◇The cabinet surface is treated with spray coating, offering strong adhesion and a high-quality texture. The entire cabinet features a matte finish, avoiding glare and creating a comfortable visual environment for operators.
◇The top cover of the cabinet can be removed when necessary to facilitate the assembly and adjustment of main busbars on-site. Lifting rings are installed at the four corners of the cabinet top for hoisting and transportation.
◇The cabinet's protection rating is IP30. Users can also choose between IP20 and IP40 based on environmental requirements. Schematic diagrams of the外形 and installation dimensions are shown in Figure 1 and Figure 2.

>>Installation and Usage

Upon arrival at the delivery location, first check whether the packaging is intact and undamaged. If any issues are found, promptly notify the relevant departments to determine the cause. For products not installed immediately, they should be stored in an appropriate location according to normal usage conditions.
◆Product Installation
Installation of the product should be carried out according to the installation diagram (see Appendix 2). Base channel steel and bolts are to be provided by the user. When installing the main busbar, the contact surfaces should be smoothed, cleaned, coated with neutral vaseline, or treated with other measures, and then fastened with bolts.
◆After installation and before operation, the following items should be inspected and tested:
◇Check whether the cabinet's surface paint is peeling off and whether the interior is dry and clean.
◇Check whether the operating mechanisms of the electrical components are flexible, without jamming or excessive operating force.
◇Verify that the switching of main electrical components is reliable and accurate, and that auxiliary contacts switch reliably and accurately.
◇Ensure that instrument indications match the transformer ratios and polarities correctly.
◇Check that busbar connections are good, and that insulated supports, mounting parts, and accessories are securely installed.
◇Confirm that auxiliary contacts meet requirements, fuse ratings are correct, relay settings comply with design specifications, and operations are accurate.
◇Ensure that circuit connections align with the electrical schematic diagram.
◇Verify that the protection circuit system meets requirements.
◇Measure insulation resistance with a 500V megohmmeter; it should not be lower than 10 MΩ.
◆Usage Precautions
◇This product is designed for freestanding installation, with single-side (front) operation and double-side door access for maintenance. The maintenance passage and cabinet doors should only be accessed or opened by qualified professionals for operation, inspection, and maintenance.
◇After multiple switching operations, the main contacts of air circuit breakers may become locally burned and accumulate carbon, increasing contact resistance. Regular maintenance and inspection of air circuit breakers should be performed according to the instruction manual.
◇Isolating switches must not be operated under load.

The manufacturer should provide the following documents and accessories upon delivery:
◇Packing list
◇Product certificate and factory test report
◇User manual
◇Relevant electrical drawings
◇Main component manuals
◇Cabinet door keys, operating handles, and spare parts as specified in the contract.
>>Ordering Information
When placing an order, users should provide:
◇Main circuit distribution system diagram and layout plan, rated operating voltage, rated operating current, protection device setting current, and necessary technical parameters.
◇Specify the规格 of incoming and outgoing cables.
◇List the models, specifications, and quantities of main electrical components inside the switchgear.
◇If busbar bridges or bus ducts are required between switchgear or for incoming cabinets, provide specific data such as span and height from the ground.
◇If the switchgear is to be used in特殊 environmental conditions,详细说明 during ordering.
◇Specify the surface color of the switchgear and any other specific requirements.

>>外形及安装尺寸