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What factors easily lead to cable failure
2024-05-06UHV-500 Cable Fault Location Detector under Wuhan UHV can help many power workers to carry out all kinds of power tests more conveniently. The occurrence of cable failure may be caused by a variety of factors, the following are the main categories of factors:Mechanical damage: Cables may be damaged by external forces such as excessive bending, stretching, digging, piling, etc. during installation, transportation and use, resulting in structural damage or even direct damage to the cable. In addition, vehicle vibration or shock load may also cause damage to underground cables.Damp insulation: Damp insulation is one of the common causes of cable failure. This can be due to poor sealing of the splice or terminal boxes that allows moisture to enter the cable, or manufacturing defects such as holes or cracks in the metal sheath that allow moisture and humidity to enter the cable. High ambient humidity and poor drainage in the cable laying area can also lead to moisture in the cable.Aging and
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The reason of resonance point can't be found
2024-05-06Resonant Test System under Wuhan extra high voltage can help many power workers more convenient for all kinds of power testing. Resonance point can not be found for a variety of reasons, the following is a list of possible reasons: Equipment resonance point beyond the host output frequency range: this may be due to the equipment resonance frequency and host output frequency range does not match, resulting in can not find the resonance point. The test device is wired incorrectly: the series resonance test device contains components such as the test host, excitation transformer, reactor, voltage divider cylinder, etc., and the connecting wires are required to connect each device with the cable under test. If the wiring is not correct, not only may not be able to measure the resonance point of the cable, but also easy on the service life of the device, and may even burn out the equipment. The device is not reliably grounded before the test: poor grounding of the device may lead to electri
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What are the main conditions affecting surface tension
2024-04-28The main conditions affecting surface tension are the concentration of solutes in the liquid, temperature, pressure and surface area of the liquid. The following will address these conditions to answer, and give the corresponding cases and solutions.Question 1: The effect of the concentration of solute in a liquid on surface tensionAnswer: The concentration of solute in a liquid has a significant effect on surface tension. When the concentration of solute increases, the surface tension decreases. This is because the solute molecules form a layer on the surface of the liquid, which reduces the interaction force between the liquid molecules, thus reducing the surface tension.Example: A user used a surface tension tester to measure the surface tension of saline solutions of different concentrations. The results show that the surface tension gradually decreases as the concentration of salt in the brine solution increases.Solution: To solve this problem, the user can adjust the concentratio
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Surface Tension Tester Advantages
2024-04-28The UHV-670 Transformer Oil Surface Tension Tester under the extra high voltage power can help many power workers to carry out all kinds of power tests more conveniently.Surface tension tester is a kind of instrument used to measure the surface tension of liquid, which has many advantages, such as high accuracy, fast measurement, easy operation, etc.. However, in the process of using it, users may encounter some common problems, which will be answered below.Problem 1: Inaccurate measurement results of surface tension testerSolution: Inaccurate measurement results of the surface tension tester may be caused by a variety of factors, such as poor accuracy of the instrument itself, contamination of liquid samples, unstable testing environment, etc. In order to solve this problem, firstly, you need to make sure the accuracy of the instrument meets the requirements and calibrate it regularly. Secondly, the liquid sample needs to be treated before use, such as cleaning and filtering, in order
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Cable fault testing multiple applications
2024-04-25The UHV-500 Cable Fault Location Detector under Wuhan UHV can help many electric workers to carry out all kinds of electric tests more conveniently. What are the main features of control cables and measures to prevent electrical interference? Cable fault testing is a commonly used testing method in power systems to detect the location and nature of cable faults. The following will address the various applications of cable fault testing, with corresponding cases and solutions. Question 1: What faults are cable fault tests used to detect in cables? Answer: Cable fault testing can be used to detect a variety of faults in cables, including open-circuit faults, short-circuit faults, ground faults and so on. Open-circuit fault refers to a section or a point in the cable is disconnected, resulting in the current can not be transmitted normally; short-circuit fault refers to a section or a point in the cable is shorted, resulting in an abnormally high current; ground fault refers to a sectio
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Methods of finding cable fault points
2024-04-24Wuhan UHV's Cable Fault Location Detector can help many power workers more convenient for all kinds of power testing.The method of finding cable fault points is an important part of power system maintenance and fault repair. The following will address the method of finding cable fault points to answer, and give the corresponding cases and solutions. Question 1: What is the cable fault finding methods?Answer: Cable fault finding methods include direct measurement and indirect measurement. Direct measurement method is to determine the location of the fault point by measuring the cable resistance, inductance and capacitance and other parameters. Indirect measurement method is through the measurement of cable voltage, current and power parameters to infer the location of the fault point. Case: A power company uses the direct measurement method to find the fault point when performing cable fault detection. They use a cable fault tester to measure the resistance value of the cable and de
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Common problems and solutions for the application of series resonance
2024-04-08The series resonance of Wuhan UHV can help many power workers to carry out various power tests more conveniently. Series resonance is an important circuit phenomenon that is widely used in radio, communication, and signal processing. However, in practical applications, there are often some common problems, and how to solve these problems has become a challenge for engineers. In this paper, we will analyze and discuss the common problems in the application of series resonance.Problem 1: A series resonant circuit cannot produce a resonant signal at a specific frequencySolution: A series resonant circuit can only produce a resonant signal at a specific frequency. If a circuit fails to produce a resonant signal at a particular frequency, it may be due to the following reasons:Inaccurate Circuit Element Parameters: Inaccurate parameters of circuit elements can lead to inaccurate resonant frequencies that fail to produce a resonant signal. To solve this problem, the parameters of the circuit
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The Detection Principle of Insulating Oil
2024-03-26The Insulating Oil Dielectric Loss Tester under Wuhan UHV Power Technology provides convenient assistance to numerous electrical workers in conducting various electrical tests. The detection principle of insulating oil mainly includes two aspects: dielectric strength and withstand voltage test.Dielectric strength is an important indicator to measure the insulation performance of insulating oil. It is defined as the maximum voltage required to produce dielectric breakdown through the material, measured in kilovolts per standard insulation thickness. The measurement of breakdown voltage is achieved by applying higher voltage to the material until leakage current causes sparks between the electrodes, indicating breakdown of the material. The standard procedure for measuring the breakdown voltage of insulating oil is to observe at what voltage sparks occur between two electrodes immersed in the insulating oil, with a specific gap usually set at 2.5mm according to prescribed standards.The p
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Transformer partial discharge test method
2024-01-11Wuhan UHV specializes in the production of partial discharge testers, which can help many power workers to carry out all kinds of power tests more conveniently.Partial discharge of transformers (reactors) can be detected by pulsed current and ultrasonic.1. Pulsed current method. There is a distributed capacitance between the transformer (reactor) winding and the core, and the discharge signal is a high-frequency signal ranging from a few hundred kilohertz to a few megahertz. It can be capacitively transmitted from the windings to the core, which generates a high-frequency current in the core clamp. If a high-frequency current transformer (HFCT) is mounted on the core or core clamp grounding wire, a partial discharge pulse signal can be detected. 2. Ultrasonic. Once a partial discharge occurs in a transformer (reactor), an ultrasonic signal will be generated and propagated to the surrounding spherical form. By placing an ultrasonic sensor on the outer wall of a transformer (reactor) tan
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DC High Voltage Generator (DC Hipot Tester) Precautions
2024-01-03The DC high-voltage generator of Wuhan UHV can help many power workers to carry out various power tests more conveniently. 1. When using DC high-voltage generators, the staff must be professionals who hold the "High Voltage Test License", first install two obvious disconnection points before the test power supply is put into the test, and the working power supply should be obviously disconnected when the items and wiring are replaced during the test. 2. Before the test, please check whether the DC high-voltage generator control box, double pressure cylinder and test ground wire are well connected. Ground the test circuit as instructed in this manual. 3. Then discharge the large capacitance test object, which should be discharged with a discharge resistance of 100Ω/V. When discharging, the discharge rod should not be immediately made to contact the test sample, and the discharge rod should be gradually brought closer to the test sample to a certain distance, and there will be a free dis
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Is sulfur hexafluoride gas toxic?
2023-12-29The SF6 gas density relay calibrator under UHV Power can help many power workers to carry out various power tests more conveniently. Sulfur hexafluoride gas (SF6) is an insulating gas widely used in the power industry for high-voltage switchgear and transformers. However, the question of whether the gas is toxic has been debated. This article will discuss the properties of SF6 gas, its application areas, and its potential harm to humans and the environment. Properties of sulfur hexafluoride gas SF6 is a colorless and odorless gas with stable chemical properties and excellent insulation properties. Since its density is greater than that of air, it has a high stability in the natural environment. In addition, SF6 has a high electrical dielectric strength, making it an ideal insulating gas for use in power equipment. Fields of application SF6 gas is mainly used in high-voltage switchgear and transformers for insulation and arc suppression. In high-voltage circuit breakers, SF6 is used for
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Earth Resistance Tester Information
2023-12-29Ground Resistance Tester is a device used to measure and test electrical grounding systems. Grounding allows for optimal electrical continuity between the conductive object and the earth. Effectively grounded equipment is permanently connected to ground by a ground connection that has a sufficiently low impedance and sufficient current-carrying capacity that does not result in dangerous voltage accumulation due to a ground fault current. Types of Earth Resistance Testers Earth resistance testers can be used to make several different measurements, including:Grounding system resistanceInsulation resistancePlanetary continuityLeakage currentGround key Grounding system resistance and insulation resistance are common measurements made using a grounding resistance tester. Grounding System Resistance Testers are used to measure grounding systems in construction projects and roads, telecommunications projects, and other applications. An insulation resistance tester measures the resistance of a
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Loop Resistance Tester
2023-12-22UHV Power's loop resistance tester can help many power workers to carry out various power tests more conveniently. The loop resistance tester is made using digital circuit technology and switching circuit technology. It is a special device for measuring the contact resistance and loop resistance of switching control equipment. The circuit resistance of a circuit breaker mainly depends on the contact resistance of the dynamic and static contacts. The presence of contact resistance increases the loss of the conductor when energized and increases the temperature of the contact point. Its value directly affects the current-carrying capacity during normal operation. Capacity, to a certain extent, affects the ability to cut off short-circuit current, and is also an important data reflecting the quality of installation and maintenance work. There are three main test methods for loop resistance testers, and the specific operations are as follows: 1. Bridge method: When measuring the resist
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Partial discharge
2023-12-22Wuhan UHV specializes in the production of partial discharge testers, which can help many power workers to carry out all kinds of power tests more conveniently. Partial discharge, mainly refers to high-voltage electrical equipment. The insulator of electrical equipment is discharged locally under the action of a sufficiently strong electric field. This discharge is limited only by the fact that the insulation between the conductors is short and no conductive path is formed. Each partial discharge will have a certain effect on the insulating medium. Slight partial discharge has less effect on the insulation of power equipment, and the dielectric strength decreases more slowly. Strong partial discharge can cause the dielectric strength to decrease rapidly. This is an important factor that causes insulation damage to high-voltage power equipment. Therefore, when designing the insulation of high-voltage power equipment, the role of long-term operating voltage should be considered, and its
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What is a Transformer Test Bench
2023-12-15Transformer comprehensive characteristics test bench is a device used for transformer characteristics testing, which can be used to test various types and specifications of transformers. The test bench can measure and record various electrical parameters of the transformer, including resistance, inductance, mutual inductance, short-circuit impedance, no-load loss, etc. The transformer comprehensive characteristics test bench can be used for the following test items: 1. Ratio test: measure the ratio of the transformer and check whether the ratio meets the design requirements. 2. No-load loss test: test the loss of the transformer under no-load conditions, including iron loss and copper loss. 3. Short-circuit impedance test: test the resistance and inductance parameters of the transformer in the short-circuit state to determine its electrical performance. 4. Load loss test: test the loss of the transformer under load conditions, including iron loss and copper loss. 5. Temperature rise te
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Vacuum test method for vacuum circuit breaker
2023-12-15The vacuum level test of the vacuum circuit breaker is very important. Once the vacuum is broken, the arc cannot be extinguished, causing the circuit breaker to explode. The vacuum test method is as follows:1. Visual inspection method. If the vacuum interrupter is a glass shell, it can be judged by the color of the suction film applied to the inner wall. The vacuum degree is good, and the film is mirror-shaped, and the vacuum degree is good, the film is mirror-shaped. It is milky white when the vacuum degree is different. Although this method is not very accurate, it can be used as a reference.2. Power frequency withstand voltage method. In the open state, the power frequency test voltage is carried out between the fractures, and it can withstand more than 10s under the power frequency withstand voltage, indicating that the vacuum degree is good. If the current also increases in the process of voltage increase, it is considered unqualified if it exceeds 5A. Of course, breakdown in the
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What is the cause of the circuit breaker failure？
2023-12-08UHV Power's circuit breaker tester can help many power workers to carry out various power tests more conveniently. Reason 1: Overload Overload protection is the basic function of a circuit breaker, and any circuit breaker has this function. Overload protection refers to the current in a circuit that exceeds the predetermined value of the circuit breaker. For example, if the predetermined value of the circuit breaker is 16A, and the actual current in the circuit is 17A, the circuit breaker will automatically trip. This is based on the maximum current protected by the circuit breaker, such as outlets, wires, and appliances. Accessory-free circuit breakers will almost certainly be overloaded; For circuit breakers with accessories, it is essential to observe if the accessories change. If there is no change in the fittings, it is also due to an overload of the circuit. The reason why a circuit is overloaded is that the total power of the appliances used at the same time in the circuit i
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Viscosity measurement method
2023-12-08The kinematic viscosity tester of Wuhan UHV can help many power workers to carry out various power tests more conveniently.There are three measurement methods for viscosity measurement: dynamic viscosity, kinematic viscosity, and conditional viscosity.1. Dynamic viscosity: the resistance generated when two liquid layers are separated by 1 cm, their area is 1 (square centimeter), the relative moving speed is 1 cm/s, and the unit is grams/mile/second. 1 g/cm·s = 1 equilibrium General: The industrial unit of dynamic viscosity is expressed in equilibrium.2. Kinematic viscosity: When the temperature is T°C, the kinematic viscosity is represented by symbols. In the International System of Units, the unit of kinematic viscosity is ST, which is square meters per second.) means that the unit is millimeters per second (i.e., 1CST = 1M2/s). Kinematic viscosity is widely used in the viscosity determination of liquid petroleum products such as jet fuel, diesel, and lubricating oil, dark petroleum p
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Introduction to Partial Discharge Testing Equipment
2023-12-07Partial discharge resistant testing equipment is a crucial apparatus in high-voltage electrical testing, primarily utilized to evaluate the insulation integrity of power systems and equipment, ensuring operational safety and reliability. This specialized equipment serves the pivotal purpose of identifying partial discharge (PD) occurrences within electrical insulation. PD is an early indicator of insulation degradation or flaws in high-voltage systems, which, if left unaddressed, can lead to catastrophic failures. The testing apparatus allows engineers to detect and analyze these minute discharges, enabling proactive maintenance and preventing potential faults that could compromise system efficiency. Operating on the principle of subjecting insulation to high voltages while monitoring for PD activity, this testing device provides invaluable insights into the insulation's condition. It assesses the endurance of insulation materials under high-stress conditions, crucial for evaluatin
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Series Resonance in Power Testing: Application and Utility
2023-12-07Series resonance serves as a pivotal principle in power testing, offering profound applications and methodologies that significantly enhance the efficiency and precision of electrical measurements. In the realm of power testing, series resonance is employed in various capacities, primarily for impedance measurement and power factor correction. By employing resonant circuits at specific frequencies, engineers can accurately measure impedance values of electrical components and systems. This precise measurement aids in evaluating the health, quality, and performance of power distribution networks, transformers, and other electrical apparatus. Moreover, series resonance finds extensive usage in power factor correction. Through the careful orchestration of inductive and capacitive elements in series, this technique minimizes reactive power losses in electrical systems, thereby optimizing energy efficiency and reducing overall power consumption. One of the prominent applications of series r
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