The selection of a DC resistance tester should comprehensively consider factors such as current specifications, measurement range, accuracy, function, power supply type, anti-interference ability, safety design, and brand service. The following are specific selection suggestions:
1. Clearly define testing requirements
① Tested object: Determine the type of transformer to be tested, its capacity, and voltage level. Transformers with different capacities and voltage levels have different requirements for testing current.
② Test scenario: Consider whether the test will be conducted in a laboratory, substation, or on-site, and whether portable devices are required.
2. Choose the appropriate current specification
① Current specifications: The DC resistance tester has various current specifications, such as 1A, 3A, 5A, 10A, 20A, 40A, 50A, 100A, etc. Generally speaking, the larger the capacity of a transformer, the greater the required testing current.
For example, transformers with a voltage level of 10kV generally use a 3-5A DC resistance tester. Transformers with a voltage level of 35kV generally use a 10A DC resistance tester. Transformers with a voltage level of 220kV typically use a 40A DC resistance tester.
② Avoid excessive or insufficient current: Excessive current can cause transformer temperature to rise, affecting the accuracy of resistance testing; If the current is too small, it may lead to insufficient testing accuracy.
3. Consider measurement range and accuracy
① Measurement range: Select the appropriate measurement range based on the DC resistance value range of the tested transformer. The DC resistance of general power transformers is between 100m Ω -100 Ω, while the measurement range of high-power inductors and other equipment is between 100 μ Ω -2k Ω.
② Measurement accuracy: The higher the measurement accuracy, the better to ensure the accuracy of the test results. High precision DC resistance testers typically have smaller resolution and lower error rates.
4. Pay attention to instrument functions
① Single phase and three-phase measurement: Select a DC resistance tester with single-phase or three-phase measurement function according to the testing requirements. The three-phase measurement function can save testing time and improve work efficiency.
② Data storage and printing: Choose a DC resistance tester with data storage and printing functions to record and save test data, facilitating subsequent analysis and report generation.
③ Temperature conversion function: Some high-end DC resistance testers have temperature conversion function, which can automatically convert the resistance value at the reference temperature based on the ambient temperature during testing, improving the accuracy of testing.
5. Consider the type of power supply
① External power supply: The DC resistance tester with an external power supply of AC220V is suitable for situations with stable power supply.
② Internal power supply (battery powered): For portable devices or situations where there is no stable power supply, an internal power supply (battery powered) DC resistance tester can be selected. However, it should be noted that currently on the market, DC resistance testers above 10A are usually not battery powered.
6. Evaluate anti-interference capability and safety design
① Anti interference capability: In strong electromagnetic field environments such as substations, choose a DC resistance tester with strong anti-interference capability to ensure the stability of test data.
Second safety design: Choose a DC resistance tester with protection functions such as overcurrent, overvoltage, and short circuit to ensure the safety of operators. At the same time, consider the protection level and structural design of the equipment to adapt to different working environments.
7. Reference brand and after-sales service
① Brand selection: Choose a well-known brand and a DC resistance tester with a good reputation to ensure the quality and performance of the equipment.
② After sales service: Understand the after-sales service policy and service content of the equipment, so that problems encountered during use can be resolved in a timely manner.
ZC-205E transformer DC resistance fast tester is our company's latest professional transformer DC resistance test equipment, which is mainly used for the DC resistance test of transformers in power systems. The instrument adopts large screen LCD display, full Chinese menu, friendly man-machine interface, complete functions, and convenient operation. It is an ideal instrument for the DC resistance test of transformers in power systems and transformer manufacturers.
Kvtester Electronics Technology Co.,Ltd. is a high-tech enterprise specializing in power testing, testing, research and development, production, and sales of testing equipment. It has been engaged in the electrical testing industry for many years, and its products are of high quality. We welcome customers to come and purchase. Service hotline: 0086-27-81778799, to learn more, visit the official website: www.kvtester.com
