Product Introduction
With the rapid development of China's electric power industry, electrical preventive testing has become an essential component of the safe operation and maintenance of power systems. Insulation diagnosis plays a critical role in detecting insulation defects or faults in electrical equipment.
Currently, electrical equipment such as transformers and generators is trending toward larger capacity, higher voltage, structural diversification, and improved sealing. This evolution demands insulation resistance testers that offer high output capacity, strong anti-interference capability, and easy portability. In response, we have designed and developed this series of meters specifically for high-interference field testing of large high-voltage transformers, electrical appliances, remote power cables, buried cables, and other electrical insulation resistance applications—suitable for high-voltage substations, power plants, and similar environments.
The instrument system integrates the advantages of analog circuits, digital circuits, and mechanical operation, achieving a leading position in output voltage, output current, measurement range, measurement accuracy, and anti-interference capability.
Product Characteristics
1. Strong Anti-Interference Capability: With an anti-electric field interference capability of up to 2 mA (50 Hz), the instrument is suitable for testing insulation resistance of 500 kV large-scale transformers in 500 kV substations without the need to disconnect wires.
2. High Short-Circuit Current: The short-circuit current is 10 mA, making the instrument ideal for testing high-capacity, high-inductance equipment.
3. Wide Resistance Measurement Range: Covers a range from 0.01 MΩ to 1999 GΩ with high resolution, ensuring accurate readings.
4. Wide Adjustable Output Voltage Range: Output voltage options include 0.5 kV, 1 kV, 2.5 kV, 5 kV, 10 kV, and 20 kV, with smooth adjustment from 0 V to the desired value.
5. Timing Function: Built-in timing function reminds users to record measurements and supports analysis of absorption ratio and polarization index of the test object.
6. High Quality: Key components are imported to ensure accuracy and reliable performance.
7. Easy to Use: Integrated single-chassis design with compact size and light weight, making it easy to carry and operate.
8. Attractive Appearance: Constructed with rugged, durable materials for enhanced texture and extended service life.
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Working principle
A high voltage digital tester is composed of medium to large scale integrated circuits. This table has high output power, high short-circuit current value, and multiple output voltage levels (with four voltage levels). The working principle is that the DC high voltage generated by the internal battery as a power source through DC/DC conversion is sent from the E pole to the L pole through the tested object, thereby generating a current from E to the L pole. After I/V conversion and division by a divider, the measured insulation resistance value is directly displayed on the LCD.
teknik parametreler
| Measurement voltage range | 0.5kV、1kV、2.5kV、5kV、10kV、20kV |
| Measurement voltage accuracy | ±(5%+10V) |
| Short circuit current | 10mA |
Measurement range and accuracy
| Ölçüm aralığı | Resistance measurement menzil | Kesinlik |
| 20MΩ | 0.01～19.99MΩ | ±(%5+3d) |
| 200MΩ | 5.0～199.9MΩ | ±(%5+3d) |
| 2000MΩ | 50～1999MΩ | ±(%5+3d) |
| 20GΩ | 0.5～19.99GΩ | ±(%5+3d) |
| 200GΩ | 5.0～199.9GΩ | ±(%10+3 gün) |
| 2000GΩ | 50～1999GΩ | ±(%20+10d) |
Temel parametreler
| Anti-electric field interference ability | 2mA(50/60Hz) |
| Zaman ve alarm fonksiyonları | maximum value of stopwatch is 19 minutes and 59 seconds. 20 minutes for a cycle. The stopwatch will tell the time at these time points: 15 seconds, 60 seconds and every 60 seconds.When telling time, resistance readings hold for 3 seconds.If the measured resistance is below the lower limit of range, the reading is invalid and the instrument will continuously sound to give an alarm. |
| Görüntülemek | three and a half bits LCD digital meter (three), respectively show test voltage, test resistance, test time. |
| Güç kaynağı | DC: rechargeable lithium battery, DC15V power supply. With AC (50 / 60Hz) special adapter access port to charge the battery. |
| Çalışma koşulları | Temperature：-20℃~+40℃；Relative humidity：20%~90% |
| Boyutlar | 315×240×180mm3 |
| Ağırlık | 5,5 kg |
Application Scenarios
Power substation inspection: Used for insulation resistance testing of high-voltage equipment such as transformers, switchgear, instrument transformers, and surge arresters to assess equipment insulation condition.
High-voltage cable testing: Used for insulation performance testing of power cables, cable joints, and terminations to identify moisture ingress, aging, and damage issues.
Motor and generator maintenance: Used for insulation testing of large motor and generator windings to evaluate equipment operational reliability.
New energy equipment testing: Used for insulation testing of high-voltage circuits in photovoltaic, wind power, energy storage systems, and battery equipment to improve system safety.
Electrical equipment production inspection: Used for factory insulation performance testing of high-voltage switchgear, electrical components, transformers, and other products.
Rail transit testing: Used for insulation condition inspection of electrical systems and traction equipment in subway and high-speed rail vehicles.
Industrial equipment maintenance: Used for routine inspection and preventive maintenance of large electrical equipment in factories to reduce failure risks.
Research and laboratory testing: Used for insulation performance research on insulation materials, dielectrics, and new electrical products.
Engineering installation acceptance: Used for insulation quality acceptance after completion of new power engineering and electrical line installations.
Fault diagnosis: Used for rapid identification of insulation degradation, leakage, and potential breakdown hazards in equipment.
FAQs
Q: What is an adjustable high-voltage digital megohmmeter, and what scenarios is it mainly used for?
A: An adjustable high-voltage digital megohmmeter is a testing instrument used to measure insulation resistance and assess the insulation condition of electrical equipment. It outputs an adjustable DC high voltage to the equipment under test, measures the leakage current, and calculates the insulation resistance value.
It is primarily used for insulation testing of power cables, transformers, motors, generators, high-voltage switchgear, and other equipment, for applications such as equipment acceptance, preventive maintenance, and fault diagnosis.
Q: Can the adjustable high-voltage digital megohmmeter replace withstand voltage test equipment?
A: It cannot completely replace it.
The adjustable high-voltage digital megohmmeter is primarily used for insulation resistance measurement and insulation condition diagnosis, determining whether the insulation performance of the equipment is satisfactory. On the other hand, AC withstand voltage testing, partial discharge testing, and other types of high-voltage tests fall into different categories and require specialized test equipment.
Q: Will testing in humid environments affect the results?
A: Yes.
When humidity is high, leakage paths may form on the surface of the equipment, which can reduce the measured insulation resistance.
Therefore, the following should be observed during on-site testing:
Keep the equipment surface dry and clean;
Record ambient temperature and humidity;
Make a comprehensive judgment based on historical data.
Precautions and other matters
1. Pay attention to safety‘ L 'is the high voltage end‘ E 'must be grounded!
2. Check the condition of the instrument. Do not use the method of suddenly connecting it when testing the power supply. Instead, connect the resistor before starting the test power supply, and then press the high voltage switch. Try to avoid sparking and discharging during work! Because high-voltage ignition and discharge can easily damage the integrated circuit components of this instrument, as well as the standard resistors or measured objects used for measurement.
3. The battery charging circuit of the instrument is charged according to the constant voltage current limiting charging method, and it takes about 6-8 hours to fully charge each time. A fully charged battery can provide continuous operation of the instrument for 6-8 hours. To ensure the battery life, the storage period of the instrument should be charged every three months.
4. Battery reassembly method: When the nickel hydrogen battery in the instrument is damaged or has poor power supply performance and needs to be reconfigured, the ten batteries that need to be reconfigured should be tested by a battery capacity tester to prove that the capacity is basically the same. Then, each battery should be fully charged before being installed into the GM megohmmeter.
