UHV-20A DC Resistance Tester
Transformer Winding DC Resistance Measurement
Measuring the DC resistance of transformer windings is an essential test during transformer acceptance, maintenance, and tap-changer adjustments. Traditional methods, such as the bridge method and voltage drop method, are often time-consuming and labor-intensive, particularly for high-power inductive equipment.
To overcome these challenges, our company has developed the DC Resistance Rapid Tester. Utilizing advanced power technology, this instrument delivers stable performance, rapid testing, compact size, lightweight design, and user-friendly operation. It achieves high measurement accuracy and excellent data reproducibility, making it the ideal solution for efficient DC resistance testing of transformer windings and other high-power inductive devices.
4、Enhanced Safety Functions: Equipped with automatic discharge and discharge indication, reducing misuse and ensuring safety for both personnel and equipment.
Parâmetros técnicos
| Item | Technical specifications and parameters | Remarks |
| Measure current | 1A, 5A, 10A, 20A | / |
| Measure Range | 1A：10mΩ~20Ω | / |
| 5A：1mΩ~4Ω | ||
| 10A：1mΩ~2Ω | ||
| 20A：1mΩ~1Ω | ||
| Precisão | ±0.2%（full range） | / |
| Data Storage | 255 | |
| Mostrar | LCD | Resistance display：4 1/2 bits |
| Maximum resolution | 0,1mΩ | / |
| Fonte de energia | AC 220V±22V，50Hz±2 Hz | Fuse 5A |
| Maximum Power Dissipation | 300W | Test current：10A/hour |
| Ambiente de trabalho | Temperature：0℃～40℃ | / |
| Relative Humidity：≤80%RH | ||
| Dimensão | 200╳400╳280 (mm) | / |
| Peso | 6kg | Including accessories |
Application Scenarios
Power transformer factory quality inspection — After transformer manufacturing is completed, perform DC resistance measurement on the high-voltage and low-voltage windings of oil-immersed transformers, dry-type transformers, and special transformers. This is used to check winding conductor connection quality, soldering reliability, and three-phase resistance balance. It is a key test item in transformer production inspection.
Substation installation, commissioning, and acceptance — After equipment installation is completed in newly built or expanded substations, perform on-site DC resistance testing on main transformers, auxiliary transformers, and distribution transformers to verify that winding and lead connections are normal during transportation and installation, ensuring the equipment meets requirements for power transmission and operation.
On-load tap-changer performance testing — For transformers with voltage regulation capability, perform resistance measurement at different tap positions to analyze the contact condition of the tap changer contacts, and determine whether there are potential fault hazards such as contact oxidation, erosion, or abnormal contact resistance.
FAQ about Transformer DC Winding Resistance Tester
What is a transformer DC winding resistance tester, and why is winding resistance testing necessary?
A transformer DC winding resistance tester is a specialized power testing device used to measure the DC resistance value of transformer windings. It calculates the winding resistance by applying a stable DC current to the winding and measuring the voltage response.Winding resistance testing can effectively evaluate winding conductor connection quality, soldering reliability, tap changer contact condition, and whether the winding has any abnormalities. It is an important testing item in transformer manufacturing, installation, maintenance, and operation and maintenance.
Does a larger transformer capacity make DC winding resistance testing more difficult?
Yes. For large power transformers, the winding resistance is relatively low, while the winding inductance is large, requiring a longer stabilization time during testing.High-performance DC winding resistance testers typically employ high-current constant-current output, fast sampling, and automatic discharge technology, which can shorten test time and improve on-site testing efficiency for large transformers.
Can the transformer DC winding resistance tester be used in conjunction with other power testing equipment?
Yes. DC winding resistance testing is typically used together with transformer turns ratio testers, insulation resistance testers, dielectric loss testers, partial discharge detection equipment, and other instruments, forming a comprehensive transformer condition testing system.By comprehensively analyzing data from multiple test items, the transformer's insulation condition, winding performance, and operational reliability can be more thoroughly evaluated.
