degree. On the other hand, the existing type test and factory test are carried out in the normal environment of the test base or factory. After the product leaves the factory, it must withstand various environmental conditions during storage and use, so the same product or the same batch Under actual conditions of use (including environmental conditions), the reliability of the product is different from that of the factory test and is reduced. The reliability under actual use conditions is the required reliability. There are three concepts of reliability: (1) reliability RN1 under actual use conditions; (2) reliability of mass production in factory/N2; (3) reliability of type test or sample test / N3. How to ensure /N, And determine /fN2, /fN3 is the content of the study, that is, to study the high-voltage switch mechanical reliability test methods, conditions, number of units, ways and data processing methods. 2 Vacuum circuit breaker mechanical reliability test method 2.1 Mechanical reliability test under normal environmental conditions The mechanical failure rate of the vacuum circuit breaker and the function curve F(iV) is in accordance with the bathtub curve. In the previous period, the failure rate was high. This section is called the running-in period and is prone to early failure. Mainly due to design defects, materials, heat treatment, processing error, surface finish, outsourcing components are not qualified, improper assembly and commissioning, so the factory test must be done 'time. At the same time, it is required that the purchased parts must pass the running-in period before assembly. Taking the operating mechanism as an example, when the factory test is made, the load of the circuit breaker is in a limit state and has a certain margin. If the overtravel 4±1mm should be adjusted to 5~5.5mm; the closing electromagnet should be below 0.85l/e (such as 0.7f/e), and the opening electromagnet should be below 0.65R (such as 0.5R). Buckle; over-current 5A should be 4.5A or 4A reliable tripping, and operate 'times to ensure the high efficiency of the transmission system to adapt to the circuit breaker assembly, parts processing, contact spring pressure, transmission system efficiency dispersion, High reliability is guaranteed. How to determine AV is an in-depth statistical analysis. According to a large number of experimental statistics, A is determined to be 500 times more appropriate. The device operates normally with the required reliability. The failure of the parts is subject to wear, deformation and weak parts, and the failure rate is greatly increased. How to determine the kg 2, also need to study. For example, if the vacuum circuit breaker has a mechanical life of 10,000 times, it means 'the number of times to the segment, = 14 times. 2.2 Environmental test and inter-effects Under the actual use of environmental conditions to ensure high reliability, not only in the normal environment, the ultimate load, short-term continuous mechanical reliability test, but also must be reliable in the extreme environment for a long time test. In addition to considering the function of the product itself, it should also consider safety, environmental adaptability and time effects, including: (1) shock and vibration during energy storage. (2) The influence of temperature, temperature and dust and harmful gases on the transmission efficiency. (3) Anti-corrosion test. If the bearing and the latch of the transmission part are rusty. (4) Aging test. Insulation aging of the closing and closing coils, overcurrent coils and undervoltage coils. (5) Time effect. If the spring generates creep for a long time and the closing work is reduced, the grease or oil is easily oxidized and hardened for a long time. (6) Equivalent test for protection and lubrication life. That is to study the special grease and test methods used in various parts of the high-voltage switch, and the evaluation criteria (technical conditions). 3 vacuum circuit breaker structure and fault analysis Vacuum circuit breaker structure block diagram As shown, the spring operating mechanism table 1 test data statistics table discussion and communication block diagram slightly. I vacuum circuit breaker I operation I transmission system II body conduction and arc extinguishing system support insulator circuit breaker structure block diagram up and down T soft connection guide and fire arc chamber system to obtain the total reliability. Since the mechanical life of the vacuum circuit breaker is 10,000 times, it is not invalid until 10,000 times. The test data is shown in Table I. Since the number of failures of each functional unit is different, corresponding to different W, there are different reliability, which can be listed. / (A-iV curve. (Finish) Club Furniture,Club Dining Chairs,Modern Club Furniture,Club Lounge Furniture Foshan Livemate Appliance Co., Ltd. , https://www.livemate-furniture.com