Partial discharge test is the main test item for power equipment insulation. What should be paid attention to when using the partial discharge tester to test?

1. The test site voltage of the partial discharge tester is as high as tens of thousands of volts. The test personnel should strictly abide by all safety precautions. The test area should have obvious and clear warning signs. Everyone on the site should know the high-voltage area. Direct test personnel should understand all live components and high-voltage components in the measurement circuit. Those who do not directly test should be isolated outside the test area. During the test and after power-on, no one should enter the high-voltage area.

2. The test site should be tidy and clean. No other irrelevant items should be stored. There should be no messy metal pieces (such as bare copper wire segments, screws, nuts, and other small metal pieces) on the ground in the high-voltage area. The tested product, step-up transformer, coupling capacitor, etc. should be kept a proper distance from the surroundings.

3. The surfaces of the tested product, step-up transformer, coupling capacitor, etc. should be kept dry and clean. Because the moisture and dirt on the surface will cause partial discharge on the surface, resulting in abnormal measurement.

4. The test operator should master the test circuit, test method, test procedure and test purpose. Before the test begins to pressurize, first connect the circuit according to the regulations, and various metal objects in the test area should be firmly grounded. Check and improve all possible discharge parts in the test area (if there are no sharp or acute angles). Particular attention should be paid to whether the wiring of the grounding wire, high-voltage wire and strong current loop is firmly connected.

5. Avoid exposing the connecting wire to prevent corona discharge. Especially for the partial discharge test with a higher voltage level, if necessary, thicken the high-voltage connection line and install an anti-corona cover to reduce the corona discharge caused by excessive field strength. The shielding cover cannot be compared with the porcelain skirt of the test product. contact.

6. Under normal circumstances, during the test, the partial discharge of the test product during the withstand voltage and pre-boost is much larger than the normal value. At this time, the instrument will inevitably exceed the full scale. To prevent damage to the instrument, Rotate the instrument's coarse gain adjustment knob counterclockwise by one or more steps, and the standard is not to exceed the full scale. When the voltage drops to the measurement voltage, turn the coarse gain adjustment switch clockwise for one or more gears. In order to record the measured value.

7. When the test is abnormal, the power supply should be cut off first. Do further processing.