I. Matters needing attention in high-voltage electricity experiment
(a) the high voltage test group must standardize the operation.
For the staff of the high-pressure experimental group, the basic requirement is to abide by the working system, that is, good physical fitness and no disease. Otherwise, it will hinder the smooth operation of high-pressure work. In addition, the staff should fully understand the process, purpose and experimental means of high voltage test. So as to take safety measures in advance and ensure the safety of experimental work. In the experiment, professionals need to make a complete experimental plan for the whole process of the experiment in order to avoid potential safety hazards in the experiment. In the high-pressure test company, it is necessary to organize staff training regularly, improve the professional quality of employees, and make an annual assessment to ensure that every employee has received on-the-job training before taking up his post and adapt to the work as soon as possible.
(2) Preparation before high-pressure experiment
Before work, each staff member is required to read the safety regulations in the operating procedures to ensure the safety of the experimental work. Staff should be able to operate high-voltage equipment professionally. For example, when dealing with the grounding problem of metal shell, the length of high voltage lead should be reduced to ensure its stability in the working process. Before carrying out the experiment, the relevant person in charge of the project must inform the staff in detail about the matters needing attention in the experiment. Before the experiment, go deep into the experiment site. For some demanding and large-scale experiments, we must make a perfect experimental plan in advance, do a good job of review and make relevant applications. Only with the approval of the superior can the experiment proceed smoothly. Only in this way can we ensure that every link of the high voltage electrical test is carried out safely. But also can ensure the life safety of the staff. If there is no scientific and reasonable experimental scheme, it will cause vicious safety accidents and may cause huge economic losses. Before the experiment, we should also pay attention to the inspection of the line, make clear the structure and direction of the line, ensure the integrity of the line and have no leakage fault. If the inspection of the line is neglected, it will bring great security risks to the later work.
(3) Matters needing attention in high pressure test
When working, the staff should wear relevant safety equipment, such as insulating clothes and shoes, to ensure the safety of the staff. Because there will be lightning strikes during work. In general, high voltage test is not conducted alone, but in cooperation with other experimental groups. However, if it is necessary to pressurize the experimental loop, the relevant personnel must be evacuated. At this time, we must inform these people in time to take preventive measures, otherwise it will cause an electric shock accident. Cause an electric shock accident. Moreover, it is often the case. Irrelevant personnel lack understanding of high-voltage test work, and often irregular operation will lead to safety accidents.
(4) Important details in high-pressure test
Capacitance and inductance are important contents of high voltage test. The characteristics of these two appliances are complete discharge and power connection, because these two appliances must be in an insulated state. If this point is ignored during the operation, it will lead to electric shock to the staff, because these devices still have high voltage charges after high voltage test. In addition, the construction personnel should also pay attention to control the power supply, and always keep the on-off signal transmission smooth during the high voltage test. If the accurate signal cannot be obtained, the staff present should always know the working condition of the power supply. These slogans should be formed in the long-term work, simple and clear, and practical. Only by doing these preventive work well can we ensure the safety of the work.
Second, the classification of high voltage electrical test
There are two main types of high-voltage tests, namely, withstand voltage test and inspection test.
(1) withstand voltage test. Its main function is to check the high voltage resistance and insulation level of equipment. However, this kind of test has advantages and disadvantages, especially its destructiveness will damage related equipment, which may seriously lead to shutdown and failure to run. But its role is also
Important. In normal experimental work, special circumstances often occur in high-voltage cable equipment, such as running in harsh environment, which will make high-voltage equipment out of normal operation and in high-load operation. Therefore, the withstand voltage test is very important at this time, because it can avoid equipment paralysis and reduce economic losses. In addition, the withstand voltage test can also enhance the withstand voltage performance of equipment and improve the performance of equipment under dangerous conditions, such as high load operation. Withstand voltage test is an important measure to avoid potential safety hazards. Driven by the withstand voltage test, it can promote the mechanical innovation of high-voltage equipment and expand the application field of high-voltage cables.
(2) detection test. Compared with the pressure test, this test is relatively stable and has little damage, which is also called nondestructive testing. The main purpose of this test is to test the internal safety of insulated wires. The test method is to judge whether the wire is damaged by low voltage. Compared with the pressure test method, the equipment with better performance is too destructive and will also cause losses. This test may be better. This test method can ensure the integrity of the external insulation system, and the insulation performance can only be tested in a lower voltage tester. To ensure the normal work.
This test method is widely used in high voltage test. The main work is to test insulation resistance or insulation oil, or to partially discharge electrical equipment. The loss of the medium is detected by detecting the performance of the medium.
(3) Special experiments. The object of this test is not the insulation performance of equipment, but the mechanical function of equipment. In this way, the operation of the equipment can be detected. It can comprehensively use the functions of various high-voltage equipment to ensure its maximum function. The biggest advantage of this test method is that it greatly reduces the security risk. It can solve the circuit system fault caused by any factor and ensure the safe operation of the circuit system.
Third, the way of laying high-voltage cables
(1) directly buried laying
The choice of cable laying method depends on the specific situation, and the factors to be considered are the density of buildings, the length of cable lines and the number of cables laid. The biggest advantage of direct buried laying is that it is very simple to operate and convenient to use, and it is the most commonly used laying method. The main application object is the open area of urban roads and buildings. When laying and weighing, we should carefully check whether the specifications and models of the coil conform to the specifications, and measure the insulation resistance to ensure that it is in good running condition. In addition, when laying cables, the distance between the cable surface at the trench bottom and the ground should be about 0.8m The trench bottom needs to be loosened properly, and corresponding signs should be set when backfilling the trench bottom, indicating that the cable is under construction. When the laying work is completed, a cable pile needs to be set every 80m at the bend and joint of the cable. Moreover, in the process of cable laying, it is necessary to maintain the road where the cable passes. Pay attention to the fact that the inner diameter of the protective tube is 65438+ 0.5 times of the outer diameter of the cable. When laying cables underground, two problems should be isolated to ensure the distance between joints and avoid dangerous accidents.
(2) Pipeline laying
Pipeline laying is mainly used for urban construction. The biggest feature of this laying method is that the channel area of the cable is very small, and there are many construction points in the city, which can adapt to different terrains. The disadvantage is that excessive heat of cables will reduce their carrying capacity, and laying pipelines and cables requires a lot of money in urban construction.
(3) Overhead laying
The general form of overhead laying of power cables is to use galvanized steel strand to hang, and set steel strand according to cable quality. If the cable quality is less than 2T per kilometer, the steel strand specification is 34mm2, and if the cable quality is less than 3.5T per kilometer, the steel strand specification is 45mm2.
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In short, in the process of high-voltage cable construction, we should take corresponding safety protection measures and use various construction technologies to ensure the safety and stability of urban power supply lines.