2, according to the purpose of the test
(1) Handover test Electrical equipment is usually constructed and installed by a special electrical installation unit. After the installation is completed, the installation unit shall test the electrical equipment when it is officially handed over to the user. This test is called the handover test of electrical equipment.
(2) Preventive test The preventive test is a test conducted on electrical equipment that has been put into operation. It is mainly based on prevention. Regardless of the operation of electrical equipment, after a certain period of operation, regular tests are carried out, usually in combination with overhaul or minor repair of electrical equipment. Preventive testing of electrical equipment is an important measure to determine whether equipment can continue to be put into operation, prevent equipment damage and ensure safe operation.
3. Classified according to different test contents
(1) Characteristic parameters Test characteristics The parameter test usually refers to testing certain electrical and mechanical characteristics of electrical equipment, such as the polarity of the coil, the wiring unit number of the transformer, the opening and closing time of the circuit breaker, and the closing contact. The minimum operating voltage of the coil and the opening and closing electromagnet coil; the measurement of various losses, no-load and short-circuit characteristics of the generator.
(2) Insulation test The insulation test refers to the test for the inspection and identification of the insulation condition of electrical equipment. According to statistics, in the various accidents of the power system, insulation accidents dominate, in order to ensure the safe operation and service life of electrical equipment, it must be tested for insulation.
4. General requirements for power testing
(1) The provisions of the “Procedures for Power Equipment Preventive Tests†and “Handover Test Procedures†are the basic requirements for inspection equipment and should be carefully implemented. In the maintenance, overhaul and handover work, the relevant personnel shall also carry out the relevant regulations on maintenance and operation issued by the Ministry, continuously improve the quality, adhere to prevention, and actively improve the equipment so that the equipment can operate in a long-term, safe and economic manner.
(2) Adhere to the scientific attitude, comprehensively and historically analyze the test results, and grasp the laws and trends of equipment performance changes. It is necessary to strengthen technical management, improve data files, carry out technological innovations, and continuously improve the level of testing technology.
(3) For electrical equipment with a rated voltage of 110 kV or less, the AC withstand voltage test shall be carried out in accordance with the “Procedure Test Procedures for Power Equipment†and the “Handover Test Procedures†(except for special regulations). For power transformers and transformers, the withstand voltage test shall be carried out after partial and complete replacement of the windings.
(4) When conducting the insulation test, separate the various devices connected together to test separately (except for the complete set of equipment), and the equipment of the same test standard can be tested together. In order to facilitate the field test work, several electrical equipments of the same test standard have been recorded in separate tests. When there are difficulties in the individual test, they can also be tested together. In this case, the test standards should be used in various connected equipment. Minimum Standards.
(5) When the rated voltage of the electrical equipment is different from the rated working voltage actually used, the standard of the test voltage shall be determined according to the following principles: 1 When the electrical equipment with higher rated voltage is used to strengthen the insulation, the rated voltage of the equipment shall be Standard test; 2Electrical equipment with higher rated voltage, when the requirements of product versatility have been met, the test shall be carried out according to the standard of the rated working voltage actually used by the equipment; 3 the electrical equipment with higher voltage level is already When meeting the requirements of high altitude or dirty areas, the test shall be carried out at the installation site according to the standard of the rated working voltage actually used.
(6) When performing various electrical tests related to temperature and humidity (such as measuring DC resistance, insulation resistance, loss factor, leakage current, etc.), the temperature and humidity of the test object and the surrounding air should be measured simultaneously. The insulation test shall be carried out under good weather conditions, and the temperature of the test object and the ambient air temperature shall not be less than 5 ° C and the relative humidity of the air shall not exceed 80%.
(7) For the measurement of the insulation resistance, a 60 s insulation resistance (R 60) is specified; the absorption ratio is measured by the ratio of the insulation resistance of 60 s to 15 s (R ​​60/R 15).
5. Requirements for electrical test personnel
(1) The test personnel must be very familiar with the relevant regulations issued by the State for the Electrical Equipment Installation Engineering Electrical Equipment Handover Test Standard and the Electric Power Equipment Preventive Test Procedures, and should be implemented carefully.
(2) It is possible to correctly grasp various test methods, correctly select and use test instruments and instruments, and clarify the precautions for each test.
(3) Be good at handling specific problems in the experiment. The selection of the test items should be as comprehensive as possible to prevent equipment with serious insulation defects from being put into operation. In preventive tests, if the time limit for power outages is limited, consideration should be given to the minimum number of test items that can effectively reflect changes in insulation conditions or insulation defects that occur during operation. In case of special circumstances, it should be able to determine the relevant test methods, cycles and standards in light of the actual situation.
(4) Continuously improve the ability to analyze and judge test results. The test results are the basis for analysis and judgment. It is very important to use the test criteria to judge the characteristics of electrical equipment and the quality of insulation. It is estimated that the development trend and severity of insulation defects are very important. Under normal circumstances, if the test results can meet the requirements of the "Standard" or "Procedures", it can be considered that the electrical equipment is intact and can be put into operation. If individual projects do not meet the requirements, or if there are no standards available for reference to older equipment, it should be possible to find out where the problem lies by comparing and analyzing.
(5) The test personnel of the acceptance unit shall always participate in the handover acceptance test, strictly control the quality of the handover acceptance, and ensure that the newly-invested equipment can operate normally.
(6) Carefully analyze the accidents of electrical equipment insulation. Electrical equipment that has been subjected to preventive tests, although most of the insulation defects can be found, is limited by the sensitivity of the test method used and the nature of the insulation defects. The presence of some invisible defects may also cause operational anomalies and accidents. The abnormal situation and accidents are investigated and analyzed, the causes are identified, and countermeasures are proposed.
(7) Pay attention to the accumulation of data. Technical data is the basis for mastering equipment performance, analyzing the trend of insulation degradation, summarizing operational experience and maintenance experience. For each type of equipment, a ledger should be established, including manufacturer's manual, handover test record and previous test reports. The established method should be From coarse to fine, from near to far, from major equipment to general equipment, gradually established and improved.
6. Test conditions for the equipment to be tested before the test
(1) The newly installed equipment to be tested shall meet the technical and technical requirements stipulated in the regulations, and the experience shall be accepted.
(2) Because the equipment that has passed the high-voltage test can be safely put into operation, no one is allowed to carry out any work that affects its running performance. Therefore, the equipment to be tested must be put into operation in a short period of time.
(3) The surrounding environment of the equipment to be tested shall have initial operating conditions and may not cause possible damage to it due to civil works and other work.
(4) For motors and transformers that are heavily wetted, they must be dried before testing.
7. Preparation before the test
(1) Before the test, the installation location, surrounding environment, model and specifications, operating history and failures of the equipment to be tested should be clarified.
(2) Check the manufacturer's instructions on the equipment and past test reports.
(3) Familiar with test standards or procedures.
(4) Formulate the correct test plan. The contents of the test plan include: test purpose, standard, wiring, test equipment, operation methods and procedures, precautions, safety measures, division of labor of test personnel, expected results, etc. When performing destructive tests on important electrical equipment, detailed test measures must be prepared before the test, and can only be carried out after approval by the relevant higher authorities.
(5) Imagine the unsafe factors that may occur in the test and formulate preventive measures.
(6) Select the appropriate test equipment and instruments, and prepare the test record sheet.
(7) For complex tests of large-scale equipment, such as generator temperature test, the participating test personnel should be clearly defined in advance in order to conduct the test in an orderly manner.
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Antenk Modular Jacks are a complete line of PCB and wire leaded jacks which are UL and CSA approved and meet all required FCC rules and regulations. Antenk offers a multitude of sizes (4P2C thru 10P10C) with styles including single, ganged and stacked versions with options of ferrite or magnetic filtering and or metal shielding. Jacks with integral LED`s,These jacks are available in thru-hole or SMT mounting.
RJ45 interface can be used to connect RJ-45 connectors. It is suitable for the network constructed by twisted pair. This port is the most common port, which is generally provided by Ethernet hub. The number of hubs we usually talk about is the number of RJ-45 ports.
RJ45 is a type of different connectors (for example: RJ11 is also a type of connector, but it is used on the telephone); there are two different ways to arrange the RJ-45 connector: one is white orange, orange, white green, blue, white blue, green, white brown, brown; the other is white green, green, white orange, blue, white blue, orange, white brown, brown; therefore, there are also wires with RJ45 connector There are two kinds: straight line and interleaved line.
The RJ-45 port of the hub can be directly connected to terminal devices such as computers and network printers, and can also be connected with other hub equipment and routers such as switches and hubs. It should be noted that when connecting to different devices, the jumper method of twisted pair cable used is different.
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