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Is a megohmmeter harmful to the human body?
2024-10-30The megohmmeter under UHV power can help many power workers conduct various power tests more conveniently.Is a megohmmeter harmful to the human body?A megohmmeter, also known as an insulation resistance tester The main function of a megohmmeter is to measure resistors with higher resistance values. Generally used to measure insulation resistance, such as the insulation performance of electrical equipment such as motors, cables, materials, etc. A megohmmeter is an insulation resistance tester designed specifically for measuring high resistance. Measuring larger resistors requires a higher input voltage. The larger the measured resistance value, the higher the required voltage. According to U=IR, when the current is constant, the higher the measured insulation resistance, the higher the required voltage. A megohmmeter can generate DC negative high voltage through circuit boosting. Usually, a megohmmeter can output 250V, 500V, 1000V, 2500V, 5000V (5kV), 10000V (10kV), 15000V (10kV), 20000
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Three schemes for checking whether a cable is live using a live cable identification device
2024-10-29The live cable identification device under UHV power can help many power workers conduct various power tests more conveniently.Nowadays, the development of the power system has become increasingly complete, and the demand for cables in the market is also constantly increasing. Today, the editor will mainly talk about three solutions for using a live cable identification device to determine whether a cable is live, including the path finding and identification of live cables, as well as the path finding and identification of cables operating at 50Hz. If you are also interested in this area, continue reading.1、 Can the problem of identifying live cables be solved?The answer is affirmative. Routing and identification of live cables, as well as routing and identification of cables operating at 50Hz.These are the three solutions for determining whether a cable is live using a live cable identification device.Routing of live cables: By clamping the transmitter onto the cable with coupling cl
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The significance of acid value detection instrument measurement
2024-10-29The acid value tester under UHV power can help many power workers conduct various power tests more conveniently.The fully automatic acid value analyzer for petroleum products (environmentally friendly) is a specialized instrument designed for laboratories. It has the advantages of small size, light weight, high accuracy, easy operation, environmental protection, and is suitable for use in harsh outdoor environments. The instrument adopts high-performance microprocessors and HDD new technology, which can analyze several samples simultaneously, automatically rotate the sample cup, automatically titrate the sample, automatically determine the endpoint of the sample, automatically print the test results, and avoid contact between staff and chemical reagents. This instrument is suitable for various laboratories such as military, power, and petroleum.Based on the acid value, the amount of acidic substances contained in the oil can be determined.2. Due to the influence of oxygen, temperature,
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Characteristics of High Voltage Switch Mechanical Characteristics Tester
2024-10-28The circuit breaker tester under UHV power can help many power workers conduct various power tests more conveniently.Suitable for mechanical characteristic testing of various SF6 switches, GIS composite electrical appliances, vacuum switches, and oil circuit switches produced domestically and internationally.Super strong anti-interference ability, able to easily and accurately test and measure even when the bypass busbar of a 500kV substation is live.Universal speed sensor (optional), linear walking speed sensor, speed sensor, easy and simple installation.High voltage switch mechanical characteristic testerAfter one switch operation, obtain all data and corresponding waveform diagrams for the mechanical characteristics test of the switch.The host can store on-site test data and use the real-time clock inside the machine to archive and save the test date and time.Host large screen, wide temperature range, direct view, background light LCD, full Chinese data and image display, LCD contra
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Selection of series resonant devices
2024-10-25The series resonance under UHV power can help many power workers conduct various power tests more conveniently.The application range of variable frequency series resonant reactance instruments is very wide, and there are many types of products on the market. Many customers do not know how to choose. In fact, the selection of reactance instruments is not complicated. We only need to grasp the key points of selection, and we can quickly choose the suitable and desirable reactance instrument.Choosing a variable frequency series resonant reactance instrument requires selecting from three elements, namely current flow value, voltage drop value, and inductance value. These three values are important criteria for us to choose products. The first factor is to choose a fixed AC current value, which focuses on heat generation. The long-term operating current value of the reactance instrument should be set from this aspect, and sufficient high harmonic component values should be considered. The a
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Preventive measures for cable faults
2024-10-25The cable fault tester under UHV power can help many power workers conduct various power tests more conveniently.1、 Reasons for moisture or water ingress in polyethylene insulated cables.Moisture or moisture enters the insulation layer of cross-linked polyethylene insulated power cables during laying, installation, and operation. There are mainly the following situations1. The cable end cover is not tightly sealed, or the cable is damaged by external forces during transportation and laying.During the transportation or laying of cables, the cable protective layer is damaged by external forces.3. Cable insulation breakdown damages the cable sheath during cable testing or operation.4. Cable accessories (especially intermediate joints directly buried) are not tightly sealed. Once moisture or moisture enters the cable insulation from the end of the cable or the outer protective layer of the cable, it may penetrate longitudinally through the copper wire shielding gap or conductor gap outside
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The difference between acousto-optic high-voltage tester and luminescent high-voltage tester
2024-10-24The voltage tester under the UHV power can help many power workers conduct various power tests more conveniently.High voltage voltage voltage tester is a specialized tool used by power companies such as power plants and substations to detect whether electrical equipment is live. On site operation has sound and light alarms, which are safe and reliable. Whether it's day or night, indoor substations or outdoor overhead lines, we can serve you correctly and reliably. It is an essential safety equipment for the electrical department of the power system and industrial and mining enterprises. High voltage voltage voltage testers are mainly used to detect whether high-voltage overhead lines, cable lines, and high-voltage electrical equipment are live. The main types of high-voltage voltage testers include luminous high-voltage testers, acousto-optic high-voltage testers, and high-voltage electromagnetic induction rotating testers.1. Luminous high-voltage voltage testerThe luminous high-vo
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Questions and Answers on Insulation Resistance Testing
2024-10-23The insulation resistance tester under UHV power can help many power workers conduct various power tests more conveniently.Insulation resistance testing is one of the most common testing techniques applicable to various electrical equipment, so we do not apologize for taking this opportunity to study some basic questions related to this important topic that are often asked.Q: What is the reason for conducting insulation resistance testing?Answer: These types of tests are usually fast and relatively easy to perform, and only require commonly used testing equipment. However, it can provide valuable early warning for potential weaknesses in insulation, which, if not taken seriously, may ultimately lead to costly and destructive in use failures.Q: What is the difference between polarization index (PI) testing and ordinary insulation testing?Answer: In the polarization index test, the insulation resistance of the test object is continuously measured for 10 minutes. Then the tester will auto
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Details of High Voltage Switch Dynamic Characteristics Tester
2024-10-23The circuit breaker tester under UHV power can help many power workers conduct various power tests more conveniently.The high-voltage switch dynamic characteristic tester is designed based on the latest "High Voltage AC Circuit Breaker" GB1984-2003, and refers to the power industry standard "General Technical Conditions for High Voltage Test Equipment" Part 3 DL/t846.3-2004 High Voltage Switch Comprehensive Tester as the design basis. It provides convenience for the dynamic analysis of various circuit breakers and can accurately measure the mechanical and dynamic characteristic parameters of various voltage low oil, multi oil, vacuum, and sulfur hexafluoride high-voltage circuit breakers. For users who are using the high-voltage switch dynamic characteristic tester for the first time, Wuhan Hezhong Electric reminds them of the following testing rules:Check and familiarize yourself with the operating instructions attached to the high-voltage switch dynamic characteristic testerIt is ver
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A Comprehensive Introduction to Insulation Oil Dielectric Loss Testing
2024-10-22The insulation oil dielectric loss tester under UHV power can help many power workers conduct various power tests more conveniently.1、 Noun Explanation:capacitanceAlso known as "capacitance", it refers to the amount of charge stored at a given potential difference, denoted as C, and the international unit is Farad (F). Generally speaking, charges move under force in an electric field. When there is a medium between conductors, it hinders the movement of charges and causes them to accumulate on the conductors, resulting in the accumulation and storage of charges. The amount of stored charge is called capacitance.(Relative) permittivityThe relative permittivity of an insulating material is the ratio of the capacitance C around and between the two electrodes of a capacitor filled with the insulating material to the capacitance q of the same electrode structure in vacuum.Replacing q with the capacitance of the electrode in air has sufficient accuracy for measuring relative permittivity.Die
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Classification and application of different types of test transformers
2024-10-21The high-voltage test transformers under UHV Power can help many power workers conduct various power tests more conveniently.This test transformer is widely used in the power industry and is highly welcomed by power workers. At present, test transformers are divided into several types: dry-type test transformers, oil immersed test transformers, and gas filled test transformers. Different types of test transformers are different.The dry-type test transformer is made of coil epoxy resin vacuum casting and is an important equipment for insulation strength and withstand voltage testing. This test transformer is suitable for on-site testing of insulation performance of various electrical equipment in power systems and power users. The coil winding and CD type iron core adopt a new technology of epoxy resin vacuum casting.Compared with oil immersed test transformers of the same capacity and voltage, dry-type test transformers reduce leakage magnetism, improve insulation strength and moisture
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Calculation formula for series resonance
2024-10-21The series resonance under UHV power can help many power workers conduct various power tests more conveniently.For ideal L and C components, when series resonance occurs, the voltage on the L and C components is equal in magnitude and opposite in direction, and the total voltage is equal to 0 (resonant impedance is zero). When parallel resonance occurs, the current in the L and C components is equal in magnitude and opposite in direction, and the total current is equal to 0 (the resonant impedance is infinite).Calculation formula for series resonanceWhen the series resonance occurs, the imaginary part of the impedance of the circuit is equal to 0, Z=R+jX, X=0, Z=R, so I=U/Z=U/R.1. Resonance definition: The energy of components L and C in a circuit is equal. When energy is released by one of the reactive components in the circuit, and the other reactive component must absorb the same energy, an energy pulsation will occur between these two reactive components.2. To generate resonance in
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The principle of batteries and the principle of battery charging and discharging testers
2024-10-18The battery charging and discharging tester under the UHV power company can help many power workers conduct various power tests more conveniently.In chemical batteries, chemical energy is directly converted into electrical energy. Depending on the internal characteristics of the battery, spontaneous oxidation, reduction, and other reactions occur on two electrodes. The negative electrode active material is composed of potential reducing agents and stable reducing agents such as zinc, cadmium, lead, etc. in the electrolyte.The positive electrode active material is composed of a potential and a stable oxidant stabilized in the electrolyte, such as metal oxides, oxygen or air, halogens and their salts, oxygen-containing acids and their salts, etc Electrolytes are materials with good ionic conductivity, such as acids, bases, salts, organic or inorganic non-aqueous solutions, molten salts, or solid electrolytes.When the external circuit is turned off, although there is a potential differenc
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A Comprehensive Introduction to Series Resonance
2024-10-17The series resonance under UHV power can help many power workers conduct various power tests more conveniently.In a series circuit composed of resistors, inductors, and capacitors, when the capacitive reactance XC is equal to the inductive reactance XL, i.e. XC=XL, the phase of the voltage U and current I in the circuit are the same, and the circuit exhibits pure resistive behavior. This phenomenon is called series resonance.Series resonance is divided into frequency modulation and induction modulation. It is generally composed of a variable frequency power supply, excitation transformer, reactor, and capacitive voltage divider. The capacitor and reactor of the test sample form a series resonant connection; The voltage divider is connected in parallel to the test sample to measure the resonant voltage on the test sample and provide an overvoltage protection signal.Series resonance, also known as series resonance transformer, variable frequency resonance, variable frequency series reson
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Precautions for using halogen moisture analyzer
2024-10-17The trace moisture analyzer under UHV power can help many power workers conduct various power tests more conveniently.1. Pay attention to the moisture regain and water absorption of the sample. If the sample has a certain moisture regain and water absorption rate, attention should be paid to the sealing and sampling time of the sample during the testing process. The sample should be sealed and stored to accelerate the sampling time;2. Set the appropriate temperature, not too high, to prevent items from evaporating, and ensure safety;3. Wear gloves and masks during the experiment to ensure personal safety;4. Sampling can be done by laying a layer of sample tray, do not stack it too high, and ensure complete drying;5. Determine if there are any vibrating substances around the instrument. Halogen moisture analyzer is a precision instrument. If there are too many vibrating substances around, it will affect the measurement results.6. After one experimental measurement is completed, wait for
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Working principle of trace moisture analyzer
2024-10-16The trace moisture analyzer under UHV power can help many power workers conduct various power tests more conveniently.Trace moisture analyzer is an electrochemical method. The Kjeldahl method is divided into two major methods: the Kjeldahl capacity method and the Kjeldahl Coulomb method. Both methods are established as standard analytical methods by many countries to calibrate other analytical methods and measuring instruments.Method IntroductionIn 1935, Karl Fischer first proposed the method of using volumetric analysis to determine moisture content, which is the visual method in GB6283 "Determination of Moisture Content in Chemical Products". The visual method can only determine the moisture content of colorless liquid substances. Later, it developed into the electricity method. With the development of technology, the Coulomb method was developed by combining the Coulomb meter with the volumetric method. This method is the testing method in GB7600 "Determination of Moisture Content i
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Characteristics of Power Frequency Series Resonance Testing System
2024-10-16The series resonance under UHV power can help many power workers conduct various power tests more conveniently.With the development of the power system, the capacity of operating equipment continues to increase. For example, the single unit capacity of thermal power units has exceeded 1000MW, and the maximum capacity of hydroelectric units has reached 800MW. If using transmissionThe unified testing equipment (power frequency test transformer) is used for AC power frequency withstand voltage testing of these devices. The voltage regulator has a large volume and requires a large testing capacity. It is difficult to solve the problem of large capacity testing power supply on site, so on-site testing is extremely inconvenient. The host of the power frequency withstand voltage tester has advantages in terms of testing power capacity, equipment waveform, and investment. The main unit of the power frequency withstand voltage tester focuses on the potential design and manufacturing of AC withs
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Correct usage method of discharge rod for DC high-voltage generator
2024-10-15The DC high-voltage generator under the UHV power company can help many power workers conduct various power tests more conveniently.The DC high-voltage generator adopts an intelligent voltage doubling circuit, greatly reducing the volume and weight of the control box and pressure doubling cylinder, making it more convenient for on-site use. By using aiPWM technology, the inaccurate linearity of PWM technology has been adjusted, greatly improving the accuracy of the instrument. Using AI technology to set overvoltage protection and overcurrent protection, instead of digital dip switches, can only set voltage values and cannot set current values and voltage drift issues. According to electromagnetic compatibility theory, special shielding, isolation, and grounding measures are adopted to ensure that the DC high-voltage generator achieves high quality and can withstand rated voltage discharge without damaging the machine.When the power switch of the DC high-voltage generator is turned on,
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Introduction to the Structure and Principle of Cable Fault Tester
2024-10-15The cable fault tester under UHV power can help many power workers conduct various power tests more conveniently.Cable fault tester is a commonly used cable fault detection equipment, which is used for various cable fault detection. Its stable performance and accurate detection make cable fault detection work more comprehensive. The work efficiency of the testing personnel has greatly improved. Today we will mainly explore the composition of a live cable fault tester.The testing composition of cable fault tester:1、 The live cable fault tester consists of the following components:1. Instrument host: Cable fault flashover tester, abbreviated as flashover tester. Cable path testing signal source, abbreviated as path tester. Cable fault fixed-point/path meter receiver, abbreviated as fixed-point instrument.2. High voltage accessory: High voltage pulse capacitor. A dual-purpose AC/DC high-voltage testing transformer. High voltage test transformer operation box.2、 The testing functions of th
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Application of DC High Voltage in Power Cable Testing
2024-10-12The DC high-voltage generator under the UHV power company can help many power workers conduct various power tests more conveniently.1. Measure insulation resistanceThe metal shielding or metal sheath and armor layer of the cable should be carried out on each phase and connected to the metal shielding and armor layer of the cable. For this test, as long as the cable is a capacitive device, the capacitive device is insulated. Attention should be paid to the resistance and absorption. For example, complete discharge before and after testing. After a round of fire, disconnect first.2. DC withstand voltage and leakage current testInsulated cables are only designed for DC withstand voltage and not for AC withstand voltage, as AC IG can cause thermal radiation; Uneven distribution of heat and electric field can easily damage cables. It should be noted that the cable core wire has a negative polarity, and after the cable is sorted, the moisture carries a positive charge. If the iron core is th
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