■ Purpose

　　The SDK(Ⅱ) low-voltage switchgear (hereinafter referred to as the device) is the latest product developed by our company based on the latest imported product technology. Starting from the mechanical structure, it integrates electrical components, electrical accessories, busbar systems, and intelligent systems, combining fixed, fixed-partitioned, and withdrawable types. Suitable for three-phase AC 50-60HZ. Rated operating voltage below 660V power supply system, used for power generation, transmission, and distribution. This device conforms to IEC439 and GB/T7251.12 professional standards.

■ Features

　　1) SDK(Ⅱ) main busbar rated current 2500A, 4000A, 6300A, short-time withstand current up to 120KA/1S. Products cover box types, fixed cabinets, fixed partitioned, and withdrawable types;

　　2) The structure uses KF and KB profiles. First, KF and KB structures use the same basic module (i.e., 25mm module). Second, SDK() considers how to compatibly use both structures in its design. This convenience is particularly prominent in MCC cabinets. In the design of SDK(Ⅱ), both high-strength, suitable for high protection level (IP54) KF structure is selected, and the MCC cabinet design can also be based on the KB structure, giving users a wider range of choices;

　　3) Position, location, locking, identification, tool unlocking, electric shock protection, and protection level are key aspects of the design of withdrawable functional units, and they are closely linked and inseparable. In short, the position of the withdrawable functional unit must be in place, the positioning must be reliable, the locking must be accurate, the identification must be clear, the unlocking must be done with tools, electric shock protection is the most important, and the protection level assists protection. The pushing mechanism of the withdrawable functional unit is designed as a single-tooth worm gear mechanism, and it cleverly solves the relationship between the number of rotations of the single-tooth worm gear mechanism and the position display (identification) as well as the electrical interlock. The withdrawable functional unit can be easily advanced into the complete set of equipment in the order of removal position → isolation position → test position → connection position, or pulled out of the complete set of equipment in the reverse order. The so-called pushing mechanism can play a role in position positioning;

　　4) Fieldbus and intelligence. The so-called intelligence refers to the use of standard fieldbus or other communication methods in the equipment. Communication-capable components are interconnected, and remote measurement, remote adjustment, remote control, and some or all functions in communication of field equipment, power grids, or controllers (slave stations) are realized through PLC or host computer (master station). The fieldbus FB (FieldBus) is a serial communication data bus technology between field devices, instruments installed in the production process area, and automatic control devices or systems in the control room. It is an industrial field-level network communication technology that realizes digital communication of field devices. From a technical perspective, products that use fieldbus technology can be considered intelligent products;

　　The SDK(Ⅱ) product is a low-voltage intelligent switchgear based on the DeviceNet bus. This product uses intelligent low-voltage electrical components and intelligent modules (or industrial PCs). It connects to the central computer through an interface and can form an intelligent control and management system to achieve centralized monitoring, data acquisition and analysis processing, centralized scheduling, parameter setting for each circuit, energy management, and establishment of equipment files. Unattended operation is possible in the switchgear room;

　　5) SDK(Ⅱ) products are compatible with mainstream withdrawable functional units on the market. SDK(Ⅱ) adopts modular design and uses the internationally recommended 25mm module as the basic module. In mainstream low-voltage complete sets of products in China, except for MNS, PGL, GCK, GGK, GCS, etc., all use 20mm module as the basic module. It should be pointed out that, first, it is temporarily impossible to accurately evaluate the advantages and disadvantages or good and bad of a basic module. The international consensus is to recommend the use of a 25mm module. Second, experience shows that in a system, modules can only be used in sets, and modules cannot be mixed. That is to say, a 25mm modular system can create a 20mm modular space, but it is not possible to use a 25mm module in one part of the system and a 20mm module in another part. Based on the above basic technical concepts, SDK(Ⅱ) products use modular interchangeability and compatibility technology to solve structural problems between different modules. Compatible with mainstream domestic products such as MNS, GCK, and GCS withdrawable functional units.

　　In solving this technical problem, the internationally used method of body replacement or line replacement is adopted, so that products with different modules can be conditionally interchanged and compatible. The so-called body replacement is to use the inner and outer layers to achieve interchangeability for products with different modules, that is, the inner layer uses the same module, and the outer layer uses the same module. The inner layer achieves interchangeability of the same module, and the outer layer achieves interchangeability of the same module. The so-called line replacement, for example, when the 20mm module is used, the linear dimension selection principle is 1, 2, 4, 6, 8, 0; while when the 25mm module is used, the linear dimension selection principle is 1, 2.5, 5, 7.5, 0; the overlapping points are 1 and 0;

　　In this way, without changing the cabinet size and busbar system of the SDK(Ⅱ) product, first, the withdrawable functional units of MNS can be compatible (because they use the same module), and for the withdrawable functional units of GCK, the line replacement method is used for compatibility (GCK height uses 200mm system), and for the withdrawable functional units of GCS and the fieldbus control cabinet, the body replacement method is used for compatibility (GCS uses 16mm system, and the industrial PC in the fieldbus cabinet is 19-inch installation. Under the condition of interchangeability and compatibility, SDK() is technically feasible, and the structural style will not change;

　　6) The protection level can reach IP54.

SDK(Ⅱ) Low-Voltage Switchgear

Modular Design

　　1) Using 25mm modular design, convenient cabinet internal space division and convenient drawer deepening function, complete and diverse connecting accessories;

　　2) Flexible interchangeability to support the actual needs of circuit schemes and engineering conditions.

Standard MCC cabinet vertical busbar system uses a new functional board design

　　Rectangular 6×60 copper busbar (top feed) and L-shaped 6×60×40 copper busbar (rear feed) compatible, maximum current 1200A, larger current design is also possible.

Diversified Circuit Solutions

　　1) Withdrawable and fixed-partitioned functional units use 7E (=175mm) height design;

　　2) 7E/4, 7E/2, 7E, 14E, 21E specifications are complete, rated current from 32A to 630A;

　　3) Supports three-phase five-wire and three-phase four-wire power supply methods, supports rear and side wiring methods.

Selection of high-quality electrical accessories

　　Ensures temperature rise and flame retardancy requirements under normal operating conditions, ensuring power safety.

Compatibility design with typical products

　　The Kf structure is compatible with mainstream similar products on the market.

Compatibility design with typical products

　　Integrated drawer design for easy installation and replacement. It uses lightweight aluminum alloy guide rails, enabling flexible and precise movement of the functional unit. The economical and effortless drive mechanism displays four positions (withdrawn, isolated, tested, and connected).

High technical performance

　　Main parameters reach the current international technical level.

■ Normal operating environment conditions

　　Ambient air temperature not higher than +40℃, not lower than -5℃, and the average temperature within 24 hours not higher than +35℃

　　Clean air, relative humidity not exceeding 50% at a maximum temperature of +40℃, higher relative humidity at lower temperatures, e.g., 90% at +20℃. However, consider temperature changes, which may occasionally cause moderate condensation.

　　Altitude not exceeding 2000m.

　　This device is suitable for transportation and storage within a temperature range of -25℃ to +55℃. It can withstand +70℃ for short periods (no more than 24 hours). Under these extreme temperatures, the device should not suffer any irreparable damage and should function normally under normal conditions.

　　If the above operating conditions cannot be met, the user and manufacturer should negotiate a solution. When this device is used on offshore oil drilling platforms and nuclear power plants, a separate technical agreement should be signed.

■ Basic parameters

　　Rated insulation voltage: Ui: 1000V

　　Rated operating voltage: Ue: 690V

　　Overvoltage category: Ⅲ

　　Rated impulse withstand voltage: Uimp: 8KV

　　Pollution degree: 3

　　Frequency: 50/60HZ

　　Main busbar rated current In: 6300A, 4000A, 2500A

　　Main busbar rated peak withstand current:

　　lpk: 110/176/220/330KA

　　Main busbar rated short-time withstand current:

　　1cw/1S: 50/80, 100/150KA

　　Vertical busbar rated current: 3200A, 2000A, 1200A

　　Vertical busbar rated peak withstand current:

　　lpkl000A时、50KA/105KA

　　Vertical busbar rated short-time withstand current:

　　lcw/1S: 80, 50, 30KA/1S

　　Protection level: IP54, IP42, IP40, IP30