YDJ-10KVA/50KV/0.2KV High Voltage Test Transformer
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I. Product Overview
The test transformer, also known as a step-up transformer, this series of products has the characteristics of small size, light weight, compact structure, complete functions, and convenient use. It is suitable for power, industrial and mining, scientific research and other departments, for various high-voltage electrical equipment, electrical components, insulating materials for power frequency withstand voltage test and DC leakage test, and is an indispensable instrument in high-voltage tests.
II. Product Structure
YD series light high-voltage test transformer iron core is single-frame type. The coil adopts concentric cylindrical multi-layer tower structure, the primary low-voltage winding is wound on the iron core, and the secondary high-voltage winding is wound on the outside of the low-voltage winding. This coaxial arrangement reduces the coupling loss between windings. The shell of the product is made into an octagonal structure that matches the core well, and the overall appearance is beautiful and generous. Transformers above 10KVA are equipped with movable nylon wheels.
YDJ-10KVA/50KV/0.2KV High Voltage Test Transformer Power Frequency Withstand Voltage Tester
III. Working Principle
YD series light high-voltage test transformer is a single-phase transformer. The working process of a single high-voltage test transformer uses AC 220V (above 10KVA is 400V) voltage into the power control box (table), through the auto-transformer inside the power control box (table), adjust 0~200V or 0-400V voltage to the primary winding of the test transformer. According to the principle of electromagnetic induction, the high voltage required for the test can be obtained on the high-voltage winding of the test transformer.
IV. YDJZ AC/DC dual-use high-voltage test transformer for DC withstand voltage and leakage test wiring method see Figure 5. Since it is an AC/DC dual-use high-voltage test transformer, the high-voltage silicon stack short-circuit rod should be pulled out from the bushing to make the test transformer in DC output state. Before doing the DC leakage test, first according to the leakage test in the output short-circuit current does not exceed the high-voltage silicon stack large rectification is appropriate, select the resistance value of the current limiting resistor (water resistor), and then according to the requirements of the test object for DC high-voltage waveform, select the capacitance value of the high-voltage filter capacitor. In order to improve the measurement accuracy of the voltage applied to the test object, a FRC resistive-capacitive voltage divider should be connected on the high-voltage side to measure the voltage.
Precautions for DC leakage test operation process
(1) Test personnel should make clear division of responsibilities, set the safety distance of the test site, carefully check the grounding of the test object and test transformer, and set up special personnel to monitor safety and observe the state of the test object.
(2) Before the test, the test object should be removed all external connections, and fully discharged, the main parts should be cleaned, keep dry, so as not to damage the test object and bring errors in test values.
(3) For large-capacity test objects (capacitors, ultra-long cables, etc.), the voltage should be raised slowly during the test to prevent the charging current of the test object from being too large and burning out the microammeter. If necessary, the voltage should be increased step by step and the stable readings of the microammeter at each voltage should be read separately.
(4) During the test, the test object, microammeter and test device should be closely monitored. Once flashing, breakdown and other phenomena occur, the voltage should be reduced immediately, the power should be cut off, and the cause should be found out.
V. Usage Methods and Precautions
2, Precautions for power frequency withstand voltage test operation process
1), Test personnel should make clear division of responsibilities, set the safety distance of the test site, carefully check the grounding of the test object and test transformer, and set up special personnel to monitor safety and observe the state of the test object.
2), The main parts of the test object should be cleaned and kept dry to avoid damage to the test object and errors in test values.
3), For the test of large equipment, generally should first carry out the no-load test of the test transformer, that is, when not connected to the test object, raise the voltage to the test voltage.
4), During the withstand voltage test, the voltage rising speed should not be too fast, and sudden pressurization should be prevented, such as sudden closing when the voltage regulator is not at zero position, and sudden power failure should also be prevented. Generally, the switch should be opened after the voltage regulator is reduced to zero position.
5), During the voltage rising or withstand voltage test, if the following abnormal conditions are found, the voltage and current meter pointers swing greatly, the test object makes abnormal sound, the insulation is found to be burnt or smoking, the voltage should be reduced immediately, the power should be cut off, the test should be stopped and the cause should be found out.
3, When using this product for high-voltage tests, in addition to being familiar with this manual, the relevant national standards and operating procedures must be strictly implemented.
Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.
