Product introduction
The transformer DC winding resistance tester is a specialized testing device used for measuring the DC resistance value of windings in power transformers, high-voltage transformers, distribution transformers, and other equipment.
The testing of DC resistance can effectively detect manufacturing defects such as material selection, welding, loose connection parts, missing strands, and broken wires in inductive coils, as well as hidden dangers that exist after operation. This instrument has the characteristics of small volume, light weight, wide range, easy operation, large output current, good repeatability, and complete protection functions. Suitable for high-precision testing of transformer winding resistance, as well as for testing the resistance of transformers and other inductive loads.
Testing Significance
(1) Check winding connection quality
If there is poor contact at winding solder joints or lead connections, it will result in abnormally high resistance values.
(2) Determine tap changer condition
Abnormal contact of tap changer contacts will cause irregular resistance changes between different tap positions.
(3) Detect winding faults
Issues such as inter-turn short circuits, broken wires, or conductor damage in the windings may cause test data to deviate from the normal range.
(4) Evaluate equipment operating condition
By comparing test data with historical records, the trend of internal condition changes in the transformer can be analyzed.
Product Characteristics
1、Display: 5.0 inch touch true color LCD, Chinese operation menu (English version can be customized).
2、Storage: 1000 test records can be stored.
3、Test mode: built-in large capacity lithium battery DC power supply, convenient for outdoor test needs.
4、Five current options: automatic.
5、High precision: accuracy 0.2% ± 2 characters.
6、Measurement range: 1u Ω~100k Ω Resolution: 0.1u Ω.
7、Printing: high-speed micro thermal printer, printing test results in real time.
8、File data management: After the instrument is connected to the computer with a USB cable, it can be used as a USB disk, and the user can copy the test record file directly from the instrument.
9、The parameter setting is more perfect. The number, material, test winding Test phase, winding temperature, converted temperature value, etc.
10、Automatic shutdown function: if the instrument does not operate within 3 minutes, it will automatically shut down.
11、Power display: after the instrument is turned on, the current battery power will be displayed on the upper right corner of the screen.
12、Under power shutdown: when the battery is low, the instrument will prompt the user and automatically shut down to Protect the battery for long-term use.
Parâmetros do produto
Parâmetros técnicos
| Tipo | integrated portable |
| Overall dimension | Length 260mm x width 160mm x height 80mm |
| Peso do instrumento | 3kg |
| Bateria embutida | DC lithium-ion rechargeable battery for both AC and DC |
| Charger input | AC220V (50±1) Hz output: DC29.4V |
| Temperatura ambiente | -10 ° C to 45 ° C |
| Humidade relativa | ≤85% RH No condensation |
| Altitude | ≤2000m |
| Instrument power | The maximum output power of this instrument is 100W (5A current level test opening voltage 20V) |
Alcance e precisão
| item | detail | Parâmetro | ||||
| Atual | 5A | Automatic、5A、1A、100mA、1mA | ||||
| Mostrar | Four and a half | |||||
| Test range | 5A | 1μΩ~4Ω | ||||
| 1A | 20mΩ~20Ω | |||||
| 100mA | 200mΩ~200Ω | |||||
| ≤1mA | 20Ω~100kΩ | |||||
| Precisão | 0.2% ±2 digits | |||||
Application Scenarios
1. Power transformer factory quality inspection — After transformer production is completed, measure the DC resistance of the high-voltage and low-voltage windings to verify winding connections, soldering quality, and tap changer contact condition, ensuring the product meets factory technical requirements.
2. Transformer installation and acceptance testing — In newly built or expanded substations, perform winding DC resistance testing after transformer installation is completed to confirm that no winding deformation, lead loosening, or contact abnormalities occurred during transportation and installation.
3. Preventive maintenance of in-service transformers — Perform regular DC resistance testing on in-service power transformers. By comparing results with historical data, promptly identify potential defects such as winding connection aging and increased contact resistance.
4. Tap changer maintenance and condition verification — After repair, replacement, or adjustment of on-load or off-load tap changers, test the winding resistance at each tap position to check contact condition and ensure stable and reliable switching performance.
5. Large power transformer overhaul acceptance — Applicable for performance testing after transformer overhaul, winding replacement, or lead repair, verifying repair quality and ensuring the equipment is returned to normal operating condition before commissioning.
6. Distribution transformer inspection and maintenance — Used for routine inspection and condition assessment of various distribution transformers in distribution networks, quickly detecting changes in winding resistance, improving equipment operational reliability, and reducing the risk of outage due to faults.
FAQ about Transformer DC Winding Resistance Tester
Why is it necessary to perform DC winding resistance testing on transformers?
Winding DC resistance is an important parameter reflecting the condition of the internal conductive circuit of a transformer. Through testing, issues such as poor lead connections, cold solder joints, broken conductor strands, and abnormal tap changer contact can be promptly identified, preventing equipment overheating, efficiency loss, or even operational failures caused by increased contact resistance, thereby improving the safety and reliability of transformer operation.
What types of transformers are suitable for use with a DC winding resistance tester?
The DC winding resistance tester is suitable for various types of equipment, including power transformers, distribution transformers, oil-immersed transformers, dry-type transformers, rectifier transformers, traction transformers, and special transformers. It can also be used for DC resistance testing of inductive devices such as reactors and motor windings, meeting diverse testing needs in the power, industrial, and manufacturing sectors.
What testing equipment is the transformer DC winding resistance tester typically used in conjunction with?
In comprehensive transformer testing, the DC winding resistance tester is typically used together with transformer turns ratio testers, insulation resistance testers, dielectric loss testers, winding deformation testers, insulating oil breakdown voltage testers, and partial discharge detection equipment. Together, they complete factory testing, acceptance testing, condition-based maintenance, and fault diagnosis, providing a comprehensive and accurate basis for evaluating the operating condition of transformers.
