GGD Low-voltage Fixed Switchgear | Electrical Energy Conversion, Distribution and Control for 380V Power Distribution Systems

Application

GGD low-voltage fixed switchgear is suitable for AC 50Hz, rated working voltage 380V, rated working current up to 3150A power distribution systems in power plants, substations, industrial and mining enterprises, for electrical energy conversion, distribution and control of power, lighting and distribution equipment.
GGD low-voltage fixed switchgear is a new type of low-voltage distribution cabinet designed according to the requirements of the Ministry of Energy, major power users and design departments, based on the principles of safety, economy, rationality and reliability. The product features high breaking capacity, good dynamic and thermal stability, flexible electrical schemes, convenient combination, strong serialization and practicality, novel structure, and high protection level. It can be used as a replacement product for low-voltage complete switchgear.
GGD low-voltage fixed switchgear complies with IEC 439 "Low-voltage Switchgear and Controlgear Assemblies", GB 7251 "Low-voltage Switchgear and Controlgear Assemblies" and other standards. GGD low-voltage fixed switchgear uses a fixed installation scheme with a simple structure and economical cost, suitable for low-voltage power distribution and lighting systems in substations, industrial and mining enterprises, with convenient maintenance and high reliability.

Operating Conditions

• Ambient air temperature not higher than +40C, not lower than -5C, average temperature within 24h not higher than +35C;
• Indoor installation and use, altitude not exceeding 2000m;
• Relative humidity not exceeding 50% at the upper limit temperature of +40C, with higher relative humidity allowed at lower temperatures (e.g., 90% at +20C), considering the possible occasional condensation due to temperature changes;
• Inclination from the vertical during installation not exceeding 5deg;
• The equipment should be installed in places without severe vibration and impact, and in locations where electrical components will not be subject to corrosion;
• Special requirements can be negotiated with the manufacturer.

Model and Meaning

Electrical Performance

◆ Basic Electrical Parameters

◆ Main Circuit Schemes
The GGD cabinet has 129 main circuit schemes designed, with a total of 298 specifications (excluding派生 schemes and specifications derived from functional changes of auxiliary circuits and control voltage changes).
Among them: GGD1 type 49 schemes 123 specifications
??? GGD2 type 53 schemes 107 specifications
??? GGD3 type 27 schemes 68 specifications
The main circuit schemes have been compiled after soliciting opinions from design and user departments, with additional schemes for power plants. The rated current is up to 3150A, suitable for auxiliary incoming and outgoing of distribution transformers up to 2000kVA. In addition, GGDJ1 and GGDJ2 capacitor compensation cabinets are designed for reactive power compensation needs, with 4 main circuit schemes and 12 specifications in total.
The auxiliary circuit design is divided into two parts: power supply schemes and power plant schemes. There is sufficient space in the GGD cabinet for secondary components. A dedicated LMZ3D type current transformer has also been developed to meet the needs of power plants and special users for supplementary relay protection.
◆ Main Busbar
Considering the price ratio and the feasibility of replacing copper with aluminum, single aluminum busbars can be used for rated currents of 1500A and below, and double copper busbars for rated currents above 1500A. The manufacturer produces prototypes according to this specification and passes type tests. Of course, the manufacturer can also replace aluminum busbars with copper busbars of the same current-carrying capacity according to user requirements. The busbar joints are treated with tinning.
◆ Electrical Component Selection
◇ GGD cabinets mainly use advanced electrical components that are already mass-produced domestically. At the same time, based on economic and reasonable principles, and fully considering feasibility, some usable older products such as DZ10 and DZ20 are retained, while discontinued products are not selected.
◇ HD13BX and HS13BX rotary operating knife switches are special components designed to meet the unique structural needs of GGD. They change the operating method of the mechanism while retaining the advantages of older products, making them practical electrical components.
◇ If the design department chooses newer electrical components with better performance and more advanced technology according to user needs, the good installation flexibility of the GGD cabinet generally does not cause difficulties in manufacturing and installation due to component updates.
◇ To further improve the dynamic stability of the main circuit, a dedicated ZMJ combined busbar clamp and insulating support are designed for GGD cabinets. The busbar clamp is thermoformed from high-strength, high-flame-retardant PPO alloy material, featuring high insulation strength, good self-extinguishing properties, and a unique structure. It can be easily assembled into single or double busbar clamps by adjusting the modular blocks. The insulating support is a sleeve-type molded structure with low cost and high strength, solving the insulation creepage distance problem of older products.

Structural Features

• The cabinet of the GGD AC low-voltage distribution cabinet adopts a general cabinet form, with the frame made of 8MF cold-formed steel sections, partially welded and assembled. Frame components and special matching parts are supplied by designated manufacturers of steel sections to ensure the precision and quality of the cabinet. The components of the general cabinet are designed on a modular basis with mounting holes on a 20mm module. The high universality allows the factory to pre-produce, shortening the manufacturing cycle and improving efficiency.
• The GGD cabinet design fully considers heat dissipation during operation. There are different numbers of heat dissipation slots at both the top and bottom of the cabinet. When the electrical components inside the cabinet generate heat, the hot air rises and is discharged through the slots at the top, while cool air continuously enters through the slots at the bottom, forming a natural ventilation channel from bottom to top in the sealed cabinet to achieve heat dissipation.
• According to the requirements of modern industrial product design, the GGD cabinet外形 and the division dimensions of each part are designed using the golden ratio method, making the cabinet beautiful and refreshing.
• The cabinet door is connected to the frame with hinge-type hinges, allowing easy installation and removal. The folded edges of the door are embedded with a rubber strip. When the door is closed, the strip between the door and the frame has a certain compression stroke, preventing direct collision between the door and the cabinet and improving the protection level of the door.
• The instrument door with electrical components is connected to the frame with multiple strands of soft copper wire, and the mounting parts inside the cabinet are connected to the frame with knurled screws, forming a complete grounding protection system for the entire cabinet.
• The surface paint of the cabinet is polyester orange peel baking paint, with strong adhesion and good texture. The entire cabinet has a matte tone, avoiding glare and creating a comfortable visual environment for operators.
• The top cover of the cabinet can be removed when necessary, facilitating the assembly and adjustment of the main busbar on site. The four corners of the cabinet top are equipped with lifting rings for lifting and transportation.
• The protection level of the cabinet is IP30, and users can also choose between IP20 and IP40 according to the requirements of the operating environment.

Installation and Operation

Upon arrival at the receiving location, first check whether the packaging is intact. If any problems are found, promptly notify the relevant department to investigate the cause. For products not to be installed immediately, place them in a suitable place according to normal operating conditions.
◆ Product Installation
Product installation should be carried out according to the installation diagram (see attached Figure 2). The foundation channel steel and bolts are to be provided by the user. During installation of the main busbar, the joint surfaces should be leveled, cleaned, coated with neutral petroleum jelly or other measures, and then tightened with bolts.
Before commissioning after installation, the following inspections and tests should be carried out:
◇ Check whether the cabinet surface paint has peeled off, and whether the cabinet interior is dry and clean.
◇ Check whether the operating mechanisms of electrical components are flexible, without jamming or excessive operating force.
◇ Check whether the making and breaking of the main and auxiliary contacts of main electrical apparatus are reliable and accurate.
◇ Check whether the instrument indications and the ratios and polarities of transformers are correct.
◇ Check whether busbar connections are good, and whether insulating supports, mounting parts and accessories are installed securely and reliably.
◇ Check whether auxiliary contacts meet requirements, whether the specifications of fuse links are correct, whether relay settings meet design requirements, and whether动作 is reliable and accurate.
◇ Check whether circuit connections comply with the electrical schematic diagram.
◇ Check whether the protection circuit system complies with requirements.
◇ Insulation resistance measured with a 500V megohmmeter should not be less than 1MΩ.
◆ Precautions for Use
◇ This product is a non-wall-mounted, single-sided (front) or double-sided door-opening maintenance low-voltage distribution cabinet. Only qualified professionals should access the maintenance access and cabinet doors for operation, inspection and maintenance.
◇ After multiple operations of the air circuit breaker, the main contacts may be partially burned and produce carbonized materials, increasing contact resistance. The air circuit breaker should be regularly maintained and inspected according to its instruction manual.

Completeness of the Product

Our company provides the following documents and accessories upon delivery:
◇ Packing list
◇ Product certificate
◇ Instruction manual
◇ Factory test report
◇ Relevant electrical drawings
◇ Cabinet door keys, operating handles and spare parts specified in the contract.

External Dimensions and Installation Dimensions

GGD1 Type Main Circuit Schemes