The dielectric strength tester for insulating oil is developed according to the national standard GB-86 <insulating oil dielectric strength measurement method>. The instrument is preset by a dial switch, and the program is executed strictly according to the preset parameters by a computer. After operation, the results can be printed as required. The instrument has strong anti-interference, simple operation and sound light prompt.
Test unfiltered processed oil medium
The recovered unfiltered oil medium is called inferior oil. It contains quite a lot of moisture and impurities for worse quality, and its dielectric strength is mostly below 12000V. Especially for the inferior oil with more moisture. Some of users also test it with the instrument measuring the high insulation strength in order to know the degree of its deterioration. As a result, the high-voltage test system of this instrument is damaged.
Normally, the gap between the two strings of balls of the high voltage electrode is filled with insulating oil. During the test, the voltage difference between the two electrodes increases with the step-by-step of the external pressure electrode. The oil dielectric with different insulation strength can bear the high-voltage electric field of different values. This rising high-voltage electric field causes the insulation oil dielectric to be suddenly broken down when it can't bear it. The transient large current during the breakdown is collected by the instrument and immediately cut off the switch and lose the high voltage, and then transferred to the step-down operation.
When testing the inferior oil with heavy water content, the voltage between the electrodes of the two hemispheres increases continuously. At the same time, the water particles in the oil medium are absorbed into the ball gap under the action of high-voltage electric field to form a light white mist water column, which becomes thicker and thinner, and the water resistance becomes smaller and smaller. This kind of slow change process that the water resistance becomes small and the high-voltage transformer increases (without breakdown and sudden discharge) causes the instrument to be damaged, the current limiting resistance, the fuse tube to burn out, etc.
|Rate of voltage rise
||0~9 min 59 sec