Winding turn to turn withstand voltage tester

RZJ-15FWinding turn to turn withstand voltage tester|Winding turn to turn withstand voltage testerSuitable for winding turn insulation testing of small and medium-sized motors and DC motors with test voltage of 3kV and below; It can also be used for inter turn insulation detection of transformer windings and electrical coil windings. Due to the inconsistent insulation structure and insulation materials of motor and transformer windings, especially the different levels of operator craftsmanship, insulation damage can occur to varying degrees in processes such as winding, wire embedding, wire scraping, joint end shaping, and handling, resulting in various forms of inter turn insulation faults in the windings. Therefore, inter turn insulation is a weak link in motors and transformers.

RZJ-15FWinding turn to turn withstand voltage testerThe circuit structure is shown in the block diagram, which consists of CRT and host system.

Working process: Powered by the mains 220V/50Hz power supply, one path goes to preheat the CRT and thyristor filaments; The other route is controlled by a delay circuit. The filament is preheated for about 5-8 minutes and controlled by the pulse signal triggering unit before the high-voltage device system is connected. The pulse energy storage capacitor is charged by high-voltage rectification, and the thyristor is controlled by the pulse signal triggering unit to form a high-voltage pulse. The high-voltage pulse is then applied to the test output terminal "VH" through the current limiting resistor to discharge and produce attenuated oscillation waves. The sampling circuit sends it to the CRT, which automatically synchronizes and tracks the signal waveform to obtain clear and stable display. The insulation performance between winding turns is determined by observing the overlap between the impulse waveform and the stored impulse waveform.

Instructions for use

1. When using with high voltage, special attention should be paid to safety during testing. The rack must be reliably grounded. Before connecting the power supply, please carefully read the technical manual to facilitate correct and safe operation.

2. Before use, check if the power supply voltage is 220V ± 5%, preferably equipped with a 5kVA AC stabilized power supply, and check if the grounding device is good. Connect the foot switch properly. Prepare the test sample, connect the instrument test line to the test sample, plug the power cord of the test instrument into a 220V power supply, and adjust the "voltage reduction" controller to 0V.

3. Turn the power switch of the tester with lock to the "ON" position, which means the power is turned on. At this time, the green indicator light of the power is on, and the display shows a scanning line or a bright spot.

4. Adjust the "vertical displacement" and "horizontal displacement" of the monitor to place the scanning line in the middle of the screen, and adjust the "brightness" and "focus" controllers to make the scanning line the thinnest, cleanest, and clearest baseline. Please refer to the oscilloscope manual for specific usage.

5. Selection of three-phase motor testing: Connect the instrument's high voltage output terminal to one phase winding of the motor, press the "high voltage press" and step on the foot switch to turn on the high voltage output and adjust the "boost" controller; Make the peak meter indicate the required amplitude of the applied shock wave. At this time, select the appropriate "V/div" and "μ s/div" levels, and adjust the "voltage fine adjustment" if necessary to make the observed shock wave attenuation oscillation waveform most distinguishable. Store the observed shock wave attenuation oscillation waveform in the oscilloscope as the standard waveform, then release the button and connect it to the other two windings in sequence. Repeat the above test. If the waveforms of the two tests are basically identical, it is qualified. If they do not coincide, the corresponding phase winding has a fault.

(Note: The normal duration for "high pressure press" during each output is 1-3 seconds; if careful observation is required, it should generally not exceed 10 seconds.)

6. Disconnect the "high voltage press" and release the foot switch, remove the test clip and install it on the next motor to be tested, and perform the second motor test, and so on.

Note: To test motors of different specifications, it is necessary to adjust the oscilloscope "LEVEL" and trigger power supply to ensure stable waveform display.