Product Introduction:
Transformer DC resistance testing is essential during delivery, installation, and handover inspections for both semi-finished and finished transformers. It is also an indispensable part of preventive maintenance testing in the power sector. This testing helps identify manufacturing defects such as issues with coil materials, welding quality, loose connections, missing strands, and disconnections, while also enabling early prediction of potential hidden dangers after the transformer is put into operation.
This DC Resistance Tester has been developed by leveraging our full technical advantages to meet the growing demand for rapid measurement of transformer DC resistance. Integrating three-phase test capabilities (supporting Yn, Y, and △ connections) along with a built-in degaussing function, this new-generation quick-testing device is ideal for measuring DC resistance in large transformers.
Featuring a large true-color high-resolution LCD screen with full-touch operation, the instrument offers a simple and intuitive user experience for on-site applications. It delivers fast testing speed, high accuracy, and a wide measurement range.
Product functions
High-precision DC resistance measurement
Adopts high-stability constant-current source output for accurate and reliable measurement results.
Supports wide-range measurement from micro-ohm to kilo-ohm levels.
Automatically calculates and displays winding DC resistance values with good repeatability and high stability.
Intelligent fast magnetization
Designed for transformer windings with large inductance, employing fast magnetization technology.
Automatically shortens magnetization time, improving testing efficiency for large transformers.
Test speed is significantly increased compared with traditional equipment.
Automatic demagnetization function
After testing, automatically initiates the intelligent demagnetization program, eliminating the need for additional demagnetization equipment.
Uses multi-stage reverse decaying current demagnetization technology to effectively eliminate residual magnetism in the core.
Automatically evaluates demagnetization effectiveness after completion, ensuring residual magnetism is reduced to a safe range.
製品の特徴
1. Comprehensive Three-Phase Testing: Supports testing of Yn-type, Y-type, and △-type windings using a unified three-phase method, with automatic calculation of the unbalance rate.
2. Wide Application Range: With a maximum output current of 20A and a measurement range of 0–200Ω, combined with an integrated degaussing function, the instrument meets numerous on-site and off-site test requirements for virtually all transformer types.
3. Intelligent Stability Judgment: During testing, the resistance change rate within 5s, 15s, and 30s is automatically calculated, assisting operators in judging data stability and preventing misreading.
4. Comprehensive Protection: Features multiple protections against back electromotive force, disconnection, and power failure, ensuring safe and reliable operation.
5. Data Storage and Printing: Equipped with a thermal printer, supports local storage of up to 200 test data items, and enables mass data storage via USB disk.
6. User-Friendly Interface: Provides a comfortable and convenient user experience with a fresh and simple 7-inch industrial true-color screen, supporting full-touch operation for intuitive control.
技術的パラメータ
Technical Indicators | |
出力電流 | Single Phase: 20A, 10A, 5A, 1A, 0.1A |
測定範囲 | Single Phase: Gear 20A 0.5mΩ~ 1 Ω Gear 10A 1.0mΩ~ 2 Ω Gear 5 A 10 mΩ~ 4 Ω Gear 1 A 0.1Ω~ 20Ω Gear 0.1A 2.0Ω~ 200ΩThree Phase: Gear 10A + 10A 0.5mΩ ~ 0.8 Ω Gear 5 A + 5 A 10 mΩ ~ 1.6 Ω Gear 1 A + 1 A 0.1 Ω ~ 8.0 Ω Gear 0.1A+0.1A 2.0 Ω ~ 80 Ω |
正確さ | ±(Accuracy×0.2%+2) |
電源 | AC220V±10%, 50/60Hz |
温度 | -10ºC~50ºC |
相対湿度 | <90%, non-condensing |
寸法 | 400mm×315mm×223mm |
重さ | 9 kg |
1. For testing winding of no-load regulating transformers, don't switch off no-load tap changer during tests or power discharging.
2. Don't disconnect test wires and cut off power switch during tests or power discharging.
3. During transformer tests, winding of the non-test side must be in open circuit.
Application Scenarios
Power transformers: Measuring winding DC resistance to check winding quality, tap changer condition, and connection status — this is the most important application scenario.
Motor equipment: Detecting whether there are broken wires, short circuits, or three-phase imbalance in generator and motor windings.
Reactors and transformers: Measuring winding resistance to evaluate equipment operating condition and maintenance quality.
Cables and busbars: Detecting conductor and joint resistance to determine whether connections are reliable.
Power equipment maintenance: Used for factory inspection, installation acceptance, preventive testing, fault diagnosis, and post-maintenance performance verification of equipment.
FAQ about Transformer DC Winding Resistance Tester
Why is DC resistance testing required for transformers?
The DC resistance of transformer windings reflects the conductive performance of the winding conductors and connection points. By measuring each phase winding and different tap positions, issues such as poor contact, broken conductor strands, soldering defects, or tap changer abnormalities can be identified, providing a reliable basis for equipment acceptance, maintenance, and fault diagnosis.
What is a DC resistance tester, and what are its main uses?
A DC resistance tester is a specialized testing device used to measure the DC resistance value of conductors or windings in electrical equipment. It calculates the resistance of the test object by outputting a stable DC current and measuring the resulting voltage drop. It is widely used in the manufacturing, installation, maintenance, and preventive maintenance of transformers, motors, reactors, instrument transformers, and other equipment, for evaluating winding connection quality and equipment operating condition.
How can the efficiency of DC resistance testing be improved?
Selecting the appropriate test current, ensuring secure connection of test clips, using the correct wiring method, and avoiding frequent switching between test objects all help to shorten test time. For multi-tap transformers, equipment that supports automatic tap testing and automatic discharge functions can further improve work efficiency.
After-sales service
1. Warranty card is included in the delivery of this product, so during delivery, please check the product carefully on the spot. If defects are found, please fill in the warranty card carefully.
2. Buyers enjoy lifelong maintenance from the date of purchase. They can show its warranty card for free repairing if problems happen within warranty period, otherwise, they have to pay for repairing and commissioning.
3. The following conditions are not in warranty:
Products are disassembled or their structure is changed by users deliberately.
Products are seriously damaged due to users' improper storage or use.
Products are damaged for other reasons on user side.
