Lista de productos
Contáctenos
Correo electrónico: qiao@hvtest.cc
Móvil: +8615871365102
Qué aplicación: +8615871365102
-
Preparation work before using a cable fault tester for testing
2025-02-21The cable fault tester under UHV power can help many power workers conduct various power tests more conveniently.What are the preparations before using the cable fault tester?1. Check the normal status of the instrumentBefore using the instrument, you can follow the following steps to check if the instrument is working properly.After the 1.1 pulse is triggered, press the power button and the instrument's main view window will be displayed on the LCD screen. The LCD screen displays text and data such as fault distance, wave velocity, measurement range, and proportion.1.2 Press the panel button, the active cursor in the middle of the instrument moves, and the fault distance data changes accordingly.1.3 Adjust the gain potentiometer, and the waveform amplitude displayed on the instrument screen will increase or decrease.If the range is changed according to the operating steps in the range menu, the range and emission pulse width on the instrument display screen will also change accord
MÁS -
What is the significance of an insulation oil dielectric strength tester?
2025-02-21The insulation oil dielectric strength tester under UHV power can help many power workers conduct various power tests more conveniently.In order to understand the withstand voltage testing work of the insulation oil dielectric withstand voltage tester, you need to know where the high-voltage power supply is connected. One side of the voltage tester is usually connected to the power safety ground (ground wire). The other side of the power supply is connected to a high-voltage conductor. This power connection can connect a given conductor in two places: high voltage or ground.When you perform two or more withstand voltage tests, you connect one contact to high voltage and all other contacts to ground. Conducting contact testing in this way ensures that it is isolated from all other contacts. What happens when you test something more complex than your first encounter? The series of contacts that connect wires, resistors, capacitors, diodes, and other components is called a "mesh" connecti
MÁS -
The difference between low voltage pulse and multi pulse in cable fault tester
2025-02-20The cable fault tester under UHV power can help many power workers conduct various power tests more conveniently.With the continuous updating of cable fault detector technology, the positioning accuracy of cable fault detectors is also increasing. At present, there are two commonly used detection techniques for cable detection equipment: low-voltage pulse method and multi pulse method. So what is the difference between low voltage pulse and multi pulse of cable fault detector?In the actual work process of cable fault detection and testing, cable faults are generally dominated by high resistance faults and low resistance faults. The low-voltage pulse method and flash method in the pulse method solve low resistance and high resistance cable faults with high accuracy and are not affected by human factors. Therefore, it has become the main application method for power cable fault detection and testing. The working principle of the low-voltage pulse method for power cable faults is to injec
MÁS -
The significance and precautions of measuring the DC resistance of transformer windings
2025-02-19The DC resistance tester under UHV power can help many power workers conduct various power tests more conveniently.By measuring the DC resistance of the transformer winding and bushing, the welding quality of the internal wire joints of the winding, the welding quality of the leads and winding joints, the tap position of the voltage tap changer and the contact between the leads and bushing, the correctness of the parallel branch connection, whether the current carrying part of the transformer is short circuited, and whether the winding is short circuited can be checked; In addition, in transformer short-circuit testing and temperature rise testing, in order to provide accurate winding resistance, it is also necessary to measure DC resistance. Therefore, the measurement of winding DC resistance is the main item of transformer testing. The handover testing standards are mandatory items;The voltage drop method or bridge method is used to measure the DC resistance of transformer windings.
MÁS -
What are the specific functions of the series resonance withstand voltage test device?
2025-02-19The series resonance under UHV power can help many power workers conduct various power tests more conveniently.The variable frequency series resonance withstand voltage test device adopts advanced variable frequency and voltage protection control technology, with reliable performance, excellent functions, and simple operation. Using the best series resonance technology and the fastest service team, we bring the best frequency resonance. It is one of the few manufacturers that has passed type test certification and is the preferred pilot test for many customers.The series resonance withstand voltage test device is mainly used in the following aspects:1. AC voltage withstand test for 6kV-500kV high-voltage cross-linked cable2. 6kV-500kV transformer power frequency withstand voltage test3. AC withstand voltage test for GIS and SF6 switches4. Generator AC voltage withstand test5. AC withstand voltage test for other high-voltage electrical equipment such as busbars, bushings, transformers,
MÁS -
How to use a microcomputer relay protection tester for frequency slip testing
2025-02-18The relay protection tester under UHV power can help many power workers conduct various power tests more conveniently.When using a microcomputer relay protection tester for testing, there is a type of test that you often need to use, which is frequency slip testing. When conducting testing, the process is quite complex and needs to be taken seriously. This article will briefly introduce how the microcomputer relay protection tester performs frequency slip testing.The rated working voltage and output voltage value under rated working conditions are generally 57.740V. Rated operating frequency: The frequency value output during testing, usually 50Hz. Calculate the current and output current values of the load under rated conditions. Load overcurrent: Based on voltage, the load control current can be offset at different angles relative to other voltages. Pre fault time refers to obtaining the output no-load (or load) state during the pre fault time, which is usually mainly used to analyze
MÁS -
How to properly use and maintain a DC high-voltage generator?
2025-02-18The DC high-voltage generator under the UHV power company can help many power workers conduct various power tests more conveniently.DC high voltage generator, abbreviated as Zhigao. Strictly following the requirements to use a DC high-voltage generator and being familiar with the following precautions will make the operation safer and more convenient. In fact, DC high-voltage generators play a safety protection role in the field of power devices and are widely used. It is worth mentioning that there are many precautions to be taken when using and maintaining DC high-voltage generators. Below, Wuhan Defu Electric has listed some precautions to help you correctly use and maintain DC high-voltage generators.1、 Precautions for Maintenance of DC High Voltage Generator:1. Prevent foreign objects from entering the control box. If the control box has a fan, check if the fan is running properly. reach2. Check the dust prevention devices at all locations. If there is any damage or loose connecti
MÁS -
In the series resonance experiment, automatic tuning of the device cannot be achieved,the reason for not being able to find the resonance point
2025-02-17The series resonance under UHV power can help many power workers conduct various power tests more conveniently.Phenomenon:The tuning curve is a straight line, and the instrument indicates no resonance point after tuningreason:Poor grounding of the circuit, incorrect wiring of the testing circuit, and open circuit of the instrument and equipmentElimination method:1) Check if the grounding device is reliable and if the grounding connection wire is disconnected;2) Check the on/off status of the high and low voltage coils of the excitation transformer; (Low voltage winding resistance; high voltage winding resistance at each output end vs high voltage tail)3) Check the continuity of each reactor; (Resistance of each winding)4) Check the continuity of the voltage divider signal line; (High and low voltage capacity)5) Check the continuity of the high and low voltage capacitor arms of the voltage divider; (Core 1 hole, shell 2 holes; 1 hole is disconnected from 2 holes)6) The device itself doe
MÁS -
What are the operating skills of cable fault tester?
2025-02-14The cable fault tester under UHV power can help many power workers conduct various power tests more conveniently.The first point is that after connecting the circuit using the multi pulse method, if the test waveform is not ideal, it is normal to apply high voltage impact for the first time. Because the distance of the fault is not known in advance, the electrical strength of the fault point is unclear. If the impulse voltage is not high enough and the fault point is not penetrated by the impulse high voltage, the fault echo cannot be collected. You can only see the waveform of the open terminal. The pulse voltage must be increased until the fault echo is seen.Secondly, sometimes the fault point is far away from the testing end and the echo is weak. Therefore, it is necessary to adjust the "length selection" to obtain a stronger fault echo. The cable fault tester has three states: "short distance", "medium distance", and "long distance". Short range is suitable for fault detection with
MÁS -
Precautions for testing the kinematic viscosity tester
2025-02-14The kinematic viscosity tester under the UHV power company can help many power workers conduct various power tests more conveniently.1. When using the instrument, the instrument casing must be well grounded;2. Before installing transformer oil in the constant temperature bath, do not turn on the heating control switch;3. The constant temperature medium in the bathtub shall not be lower than half of the upper part of the expansion part of the viscometer;4. Continuous use should pay attention to whether the oil level of the transformer in the constant temperature bath has decreased. If it is too low, it should be replenished at any time. If there are impurities in the transformer oil, they should be promptly treated, eliminated or replaced;5. Do not unplug or insert any connecting wires without unplugging the power plug;6. The constant of capillary viscometer should be safely backed up;7. Pay attention to replenishing cleaning solution and draining waste oil from the waste liquid storage
MÁS -
Common problems and precautions of series resonance experimental device
2025-02-13The series resonance under UHV power can help many power workers conduct various power tests more conveniently.In the use of series resonance equipment, we often encounter some problems. For example, the problem of the fan not starting when using the series resonance equipment:1) Failure to press' fault reset 'after emergency stop, fault protection, and mismatch protection;2) Internal temperature too high, power component overheating protection;Troubleshooting method: Turn off the instrument power, let the instrument stand for about 30 minutes, turn on the power again, press the "Reset" button on the instrument panel, and then start the instrument.If the fan still cannot start, please contact the manufacturer. Please do not remove the instrument!In addition to the grounding wire of the power cord, the grounding pole of the product casing must also be grounded. To prevent electric shock, the grounding conductor must be grounded. Before connecting the input or output terminals of
MÁS -
The usage method of transformer oleic acid value tester
2025-02-12The acid value tester under UHV power can help many power workers conduct various power tests more conveniently.In practical work, if electricians want to test the oleic acid value of transformers, they need to use an acid value tester. This equipment is a type of testing device used in transformer oil testing and is often needed. It is convenient and popular to use. So, how to use a specialized transformer oil acid value tester? This article will provide you with a brief introduction.The acid value tester adopts the principle of neutralization method. At room temperature, the microcomputer system internal control enterprise can automatically complete liquid addition, stirring, titration, and endpoint judgment. Adopting a touch sensitive LCD screen to develop time parameters for all resource management accounting work, the human-machine dialogue interface design is simple and friendly, the operation method is simple and convenient, and the research cycle for analyzing the average servi
MÁS -
Precautions for DC withstand voltage test
2025-02-12The DC high-voltage generator under the UHV power company can help many power workers conduct various power tests more conveniently.1. Before testing, conduct a test on the cable and fully discharge it to the ground; Disconnect the devices connected at both ends of the cable and do not connect any other devices during the testing process; Clean the insulation surfaces at both ends of the cable head to reduce leakage current caused by the surface. If necessary, insulation barriers should be installed between the phases of the cable head.2. Safety measures such as fences should be taken at the testing site. Especially at the other end of the cable, a warning sign should be hung and a dedicated person should be assigned to guard to prevent outsiders from approaching, and to check whether the grounding wire and discharge rod are well connected.3. When applying pressure, the voltage should be gradually increased to prevent excessive charging current. After staying at 0.25, 0.5, 0.75, and 1.
MÁS -
The steps for testing cable faults with a cable fault tester
2025-02-11The cable fault tester under UHV power can help many power workers conduct various power tests more conveniently.Step 1: First, use a rangefinder to measure the distance. In fact, the first step is to determine whether the cable fault is high resistance, low resistance, or grounding. Different testing methods have been adopted to address this situation. If it is a ground fault, use the low voltage pulse method of the rangefinder to directly measure the distance. If it is a high resistance fault, high-voltage pulse discharge method needs to be used to measure the distance, and auxiliary equipment such as high-voltage pulse capacitors, discharge balls, current limiting resistors, inductance coils, and signal samplers need to be used to measure the distance.Step 2: Find the path (if the path is clear, it can be omitted). When searching for a path, a signal (path signal generator) is added to the cable, which is then received by a receiver and used to determine the cable path along the pat
MÁS -
Cleaning method for oil cup of insulation oil dielectric loss tester
2025-02-11The insulation oil dielectric loss tester under UHV power can help many power workers conduct various power tests more conveniently.Cleaning the oil cup is a very important preparation work when measuring the loss value of insulating oil with an insulation oil dielectric loss tester. Some unreliable measurement results are often caused by incomplete cleaning of the oil cup. Therefore, strict cleaning methods must be followed to obtain reproducible and reliable measurement results.When conducting the identification test of insulation oil loss coefficient, the oil cup should be thoroughly cleaned before each test. The cleaning steps are as follows:a. Completely remove the oil cup and clean all components with chemically pure petroleum ether (distillation range 60-90 ℃) and benzene in sequence.b. Rinse all components with acetone, then clean with neutral detergent.C. Boil all components in 5% trisodium phosphate in distilled water for 5 minutes, then rinse several times with distilled wat
MÁS -
Cable aging and faults
2025-02-10The cable fault tester under UHV power can help many power workers conduct various power tests more conveniently.reason1. External force damage. Based on operational analysis in recent years, especially in Shanghai Pudong where the economy is rapidly developing, a considerable number of cable failures are caused by mechanical damage.2. Insulation is damp. This situation is also very common, usually occurring at cable joints buried directly or in ducts. For example, if the cable joint is not made properly or if the joint is made under humid weather conditions, it will cause water or steam to enter the joint. Over time, under the action of an electric field, water branches will form, gradually damaging the insulation strength of the cable and causing faults.3. Chemical corrosion. Directly burying cables in areas with acidic or alkaline effects often causes corrosion of the cable's armor, lead sheath, or outer protective layer. The protective layer may fail due to long-term chemical o
MÁS -
What are the contents of insulation prevention test?
2025-02-08The insulation resistance tester under UHV power can help many power workers conduct various power tests more conveniently.Maintaining good insulation is crucial for high-voltage electrical testing equipment during operation. Therefore, every step of the equipment from production to use must undergo a series of insulation tests, including raw material testing during the production process, factory testing, handover testing, operation and maintenance insulation prevention testing, etc. Wait. Among them, handover testing and preventive testing of electrical equipment are two important types of testing. This section focuses on the content of insulation prevention tests.1. Insulation resistance testInsulation resistance testing is a widely used and convenient method in electrical equipment insulation testing. The magnitude of insulation resistance can effectively reflect the overall moisture, pollution, and severe overheating aging of the insulation. The commonly used instrument for testin
MÁS -
How to solve the fault of the circuit resistance tester?
2025-02-08The circuit resistance tester under UHV power can help many power workers conduct various power tests more conveniently.1. [Phenomenon] When connected to a 220V AC power supply, the fan does not make any sound. When the "test switch" is pressed, the ammeter and micro ohmmeter do not display. 【 Reason 】 The 220V AC power supply is blocked, and the fuse is not installed or blown. 【 Exclusion Method 】 Check and exclude. The 100A instrument fuse will burn out again if it is not lower than 6A, and the factory will solve it. (Do not connect to DC or 380V AC power supply)2. 【 Phenomenon 】 Press the 'test switch', the ammeter displays no current, and the highest position of the micro ohmmeter displays' 1 '. [Reason] The 100A current circuit connection is incorrect. The tested switch is not closed. [Processing] Check the probe, reconnect it, and re clamp it. Turn off the switch.3. [Phenomenon] The test current is normal, but the highest micro ohm value is displayed as "1". [Reas
MÁS -
The importance of dielectric strength testing of insulating oil
2025-02-07The specialized production of insulation oil dielectric strength tester for UHV power can help many power workers conduct various power tests more conveniently.As a medium filled in electrical equipment, insulating oil has many advantages such as insulation, heat dissipation, and arc extinguishing, and is widely used. For example, large power transformers use insulating oil for insulation and heat dissipation. But there is a discharge fault inside the transformer. Under the action of voltage, insulating oil undergoes a series of chemical reactions such as light, heat, and electricity. It is also crucial to regularly test the insulation oil during use in order to reduce its voltage resistance performance.The breakdown voltage of insulating oil is an indicator of its ability to withstand voltage inside electrical equipment and is one of the main means of inspecting the quality of oil insulation. Here we use an insulation oil dielectric strength tester produced by ultra-high voltage to co
MÁS -
What is partial discharge (PD)?
2025-02-07The specialized production of partial discharge testers for UHV power can help many power workers conduct various power tests more conveniently.What is (partial discharge) PD and why do we need to test it?PD is a discharge that occurs in a localized area of insulation between two conductive electrodes, without completely bridging the gap (see IEC 60270) It may be caused by discontinuities or defects in the insulation system. PD activity is an indication of early medium voltage (MV) or high voltage (HV) insulation faults and is widely regarded as the best warning indicator for electrical insulation degradation of medium and high voltage electrical assets in power networks. Generally speaking, partial discharge occurs in systems with a voltage of 3 kV or higher; However, it should be noted that in some cases, PD may also occur at lower voltages (i.e. variable speed drive/variable frequency drive motors and LV designs). The typical driving factors for implementing PD plans include: suppor
MÁS
