Shanghai Qianshi analyzes the operation of three-cup insulation oil dielectric strength tester

What are the conditions to be considered when using the three cup insulating oil dielectric strength tester? 5hWTextile Testing Instruments, Testing Equipment Manufacturer

1. Testing for inferior oil, the instrument is easy to damage.5hWTextile Testing Instruments, Testing Equipment Manufacturer

The recovered unfiltered oil medium is called inferior oil, which contains a lot of water and impurities. Mostly below 12 kV. Especially for low-grade oil with a lot of water, some users also use a high withstand voltage meter to test the low-grade oil to find out how bad it is. Because of this, the high-voltage test system of the instrument is easy to be damaged. 5hWTextile Testing Instruments, Testing Equipment Manufacturer

Normally, the high-voltage electrodes are filled with insulating oil. During the test, the voltage between the two electrodes keeps increasing, and oil media with different insulation thicknesses can withstand different strength high-voltage electric fields. This rising elhigh-voltage electric field will cause the insulating oil media to collapse suddenly, it cannot withstand it. The large current is collected by the instrument and immediately shuts down, losing high voltage and going into buck mode. 5hWTextile Testing Instruments, Testing Equipment Manufacturer

When testing low-grade oil with high water content, the voltage between the electrodes of the two hemispheres continues to increase, and at the same time, the water particles in the oil medium are adsorbed in the gap between them. The spheres form a pale white color under the action of a high-voltage electric field. The fog-like water column changes from thin to thick and the water resistance becomes smaller and smaller. Such a transient process, in which the water resistance becomes smaller and the current of the high-voltage transformer increases (without breakdown and sudden discharge), will cause damage to the instrument, the current-limiting resistor, the fuse blowing, and even the high-voltage transformerr of the instrument is burned. 5hWTextile Testing Instruments, Testing Equipment Manufacturer

2. Low-pressure oil medium test5hWTextile Testing Instruments, Testing Equipment Manufacturer

This type of oil medium usually has a voltage of 15-35KV. Even if the oil medium contains a small amount of water and impurities, the device cannot work normally. It only shows that individual bubble particles (or impurities) are adsorbed in the ball gap to generate discharge during the boosting process, and the bubbles are scattered and pushed out of the ball gap, and the oil is refilled, so that the pressure will continue increased up to the bearing point of the oil medium. Through the collapse, this test data is still reliable. 5hWTextile Testing Instruments, Testing Equipment Manufacturer

3. Test for inferior oil5hWTextile Testing Instruments, Testing Equipment Manufacturer

To filter the recovered oil medium, such as B. Water droplets or impurities visible to the naked eye, do not use force testing instruments. In the low-quality oil medium that has been stored for more than 24 hours, large sinksWater droplets fall to the bottom of the oil and fine particle bubbles float to the top of the oil. The user must use a non-water polluted device to take the oil sample in the middle part and closely observe during the test whether there is a thin thread-like column of fog during the boost (starting with the initial boost period). If this is detected, power should be shut off immediately. Test it out. If there are multiple points of continuous discharge during the boosting process, the instrument cannot be shut down automatically and the user should immediately turn off the power and stop the test. 5hWTextile Testing Instruments, Testing Equipment Manufacturer