The capacitive equipment is widely used in electric power system. However

the air bubbleinside the insulation may lead to partial discharge

and cause the dissolved gas contents in the oil to vary

and cause further development of discharge and

consequently lead to the insulation breakdown.Therefore

it is very important to study the dissolved gas contents so to assure reliable operation of thecapacitive equipment. In this paper

several cases caused by oil-immersed current transformer andbushing in Fujian Province is used to analyze the oil chromatographic data of failure equipment before andafter operation and compare it with that of the healthy equipment so to obtain the information on thedifference of the gas contents in the faulted and healthy equipment. It is shown by the study result that thecapacitive equipment

especially the inverted current transformer

has high requirement inmanufacturing process. Any defect of insulation process can lead to bubble on the oil paper insulationsurface and quality defects and

at the same time

the oxygen contents monitoring in the currenttransformer is proposed so to prevent insulation fault. And above study can provide a definite reference forboth the current transformer manufacturer and the utilities.