Table 2 focuses on the main technical performance indicators of universal circuit breakers, molded case circuit breakers (including motor protection circuit breakers), AC contactors, etc. in low-voltage 4 products at home and abroad. Universal Circuit Breaker The universal circuit breaker produced in China before H is roughly divided into three grades. The first product is represented by DW16, and the protection features are overload long delay and instantaneous two-stage protection. It is characterized by flat layout, fixed installation, side handle operation, simple structure, convenient maintenance and low price. It is suitable for general industrial systems that do not require selective protection or the vast rural distribution system. It is an alternative to DW10. There are AE, 3WE, AH and other products. Its main features are: the breaking ability is relatively ambiguous; it has three-stage protection characteristics and selective protection function; the central operating handle has two structures: fixed type and withdrawable type. This product is suitable for general industrial systems. The third product is represented by DW45 and M series, as well as DW40, F and other products. Its main features are: high breaking capacity, no arcing, perfect protection characteristics, intelligent function, frame-plastic structure, beautiful appearance and modular structure of accessories. This product is suitable for large-capacity power distribution systems, key projects, hotel hotels, office buildings, and metropolitan substations. The technical performance indicators of the main universal circuit breakers currently produced are shown in Table 1. Plastic circuit breaker molded case circuit breakers are generally divided into two categories according to their main purposes: one is based on distribution protection, and can also be derived from motor protection; Class is a motor protection circuit breaker. The main difference between the two is that the characteristics of the motor protection circuit breaker must be adjustable on the panel, and its performance must meet the relevant standards of the starter in addition to the circuit breaker standard. The technical performance indicators of the main series of molded case circuit breakers currently produced by distribution protection are shown in Table 2. -20 is a self-designed product in the mid-1960s in China. It is large in size and technical and economic indicators are backward. The maximum rated current is 20A. The maximum power of the control motor is 10kW, and the rated short-circuit breaking capacity is 15kA. There is no accessory except the built-in auxiliary contact. M611 and 3VE1 were manufactured by foreign technology in the 1980s. The performance index is one step higher than DZ5-20, and has a variety of accessories, but the breaking capacity is not high, and the technical indicators are still relatively backward compared with the current international level. A new generation of motor protection circuit breaker developed by the product, rated current 25A, control motor power is 12.5kW, rated short-circuit breaking capacity for the product. Table 1 Model rated voltage (V) Overcurrent release range (A) AC short circuit breaking capacity (kA) Remarks Applicable to the fixed installation site requiring sample protection F is the instantaneous short circuit breaking capacity, the denominator is short delay Short-circuit breaking capacity, 1600A and below, drawer type, drawer type, f, 660V, denominator, 380V, drawer type, drawer type, rated voltage (V), overcurrent release range (A), short-circuit breaking capacity (kA) Remarks Floating core type hydraulic release DZ20C-160 shape, installation size and wiring method are the same as DZ10-100-1 standard to determine air type AC, DC contactor and vacuum contactor. Air AC contactors include rotary contactors, direct-acting contactors, and switching capacitor contactors derived from direct-acting contactors. The largest production is direct-acting AC contactors, mainly C20. B, 3TB, LC1-the overall level is quite international": 20ttt in the early 1980s, the main technical data are shown in Table 3. Some of the new Hall-type circuit breakers that were sweating in the 1990s, such as the French Schneider WMå°•Column, Germany's Siemens 3WN6 series, ABB's F series, Japan's Mitsubishi SuperAE series and the United States GE's S series. The main technical performance indicators of the products are shown in Table 4. Small, some products reach no arcing, most products in and out of the line interchange does not> reduce the breaking capacity; with intelligent functions, including various protection functions, external fault memory, internal faults Diagnostics, communication dialogue, etc.; internal accessory structure is modular, installation and building blocks, and the whole series is common, such as shunt release, undervoltage release, alarm device, etc.; derivative specifications and external accessories are complete, including front and rear panels Terminal block, fixed, withdrawable installation, straight shank manual energy storage, electric energy storage, mechanical interlock (horizontal, vertical), door interlock, padlock, auxiliary switch, terminal block, etc. The main performance indicators of the new generation of molded case circuit breakers of plastic circuit breakers are shown in Table 5. The newly designed or improved products of the motor protection circuit breakers further improve the breaking capacity and add various additional functions, making them suitable for use in various motor control centers. For example, the West I' subsidiary introduced the 3VU series in the 1990s instead of the original 3VE series. The rated working voltage is 660V, and the rated working current is 52A.3VU. It adopts serialization, modularization and modular design, and has various accessories, such as. Shunt trip, under voltage trip, short circuit fault display, remote operating mechanism, external auxiliary contact, door interlock operating mechanism, isolation module, various protective housings and additional terminal blocks. In addition to the above accessories, Schneider's GV2 series motor protection circuit breakers can be assembled with flexible and additional modules, which can be combined with D2 contactors to form an automatic motor starting device. The combined electric appliance has the advantages of both the motor protection circuit breaker and the contactor, and has high reliability, safe operation and convenient and flexible installation. Development and competition in the international market, in the late 1980s and early 1990s, some major foreign AC contactor manufacturers introduced a new generation of AC contactors: LC-D series of French TE company, 6C series of American SpuareD company, 3TF of German Siemens company Series, KM company's DIL series, Japan's Mitsubishi MS-N series, Qisheng company's 6C series. The main indicators of these products, such as the highest rated working voltage of 660V, mechanical life of 1000 million times, electrical life of 100 ~ 1.2 million times (AC-3), the highest operating frequency of 1200 times / h, etc., basically maintained at the original level. Because these indicators can meet the requirements of various industrial automatic control systems, blindly improving technical indicators will increase costs and reduce the market competitiveness of products. Table 3 AC contactor variety model rated electrical rated current (A) mechanical life (10,000 times) electrical life (10,000 times) rotary contactor therapeutic contactor capacitor contactor container) Table 4 technical performance France Schneider M series Italy ABB F series Germany Siemens 3WN6 series H Mitsubishi Ae-SS series UK GE company S series rated current (A) rated voltage (V) rated limit short-circuit breaking capacity UV) rated operating short-circuit breaking capacity (kV) rated short-time withstand current Shape size table 5 technical performance volume (length x width x height) short circuit breaking capacity / unit volume (itfA.mm2) H this Mitsubishi PSS series American series company France Schneider Corporation Japan Fuji company series (Finish) Table Line,Custom Placemat,Cotton Placemat,Printed Placemat Jinan Huatian Leinuo Trade Corporation Ltd. , https://www.huatianleinuo.com