As a medium filled in electrical equipment, insulating oil has many advantages such as insulation, heat dissipation and arc extinguishing, and is widely used. For example, large-scale power transformers use insulating oil to insulate and dissipate heat. But there is a discharge fault inside the transformer. A series of chemical reactions such as light, heat and electricity occur in insulating oil under the action of voltage. In order to reduce the voltage resistance performance of insulating oil, it is also crucial to regularly test the insulating oil in use.
The breakdown voltage of insulating oil is a measure of its ability to withstand voltage inside electrical equipment, and is one of the main means to test the quality of oil insulation. Here we use the HZJQ-X1 insulating oil dielectric strength tester to do the oil withstand voltage test. According to the relevant regulations, the test electrode should be made of brass, with a diameter of 25 mm, a thickness of 4 mm, and a chamfering radius of 2 mm. The capacity of the oil cup in which the electrodes are placed should be 200 ml, and the oil cup should be made of porcelain or glass.
In the process of taking oil samples, the insulating oil must be well preserved, and it should not be mixed with other liquids or sundries, nor should it be exposed to the air for a long time. Put the oil sample in the oil cup and let it stand for 10 minutes to start the test. The instrument automatically boosts the voltage from zero, the boosting speed is about 3KV/S, and the current is limited to 5mA until the oil gap breaks down, and the breakdown voltage value is recorded. , and repeat the test 5 times to get the average value. Compared with the standard breakdown voltage, the 500KV system should be greater than 60KV; the 330KV system should be greater than 50KV; the 220KV~60KV system should be greater than 40KV; the voltage level of 35KV and below should be greater than or equal to 35KV.
