Current transformers commonly have the following three abnormal conditions:
(1) Overheating of the current transformer may be caused by loose internal or external connections, primary overload, or secondary open circuit;
(2) Abnormal noise from the transformer may be due to loose core or components, improper electric field shielding, secondary open circuit or potential floating, open circuit of the end screen, and discharge due to insulation damage. During testing with the transformer comprehensive tester, only the test voltage/current values need to be set, and the device can automatically boost voltage/current and quickly display the volt-ampere characteristic curve or transformation ratio, polarity, and other test results;
(3) Abnormal chromatographic analysis of dissolved gases in insulating oil should be judged and tracked according to GB/T7252. If only the hydrogen content exceeds the standard, with no obvious increasing trend, and other components are normal, it can be judged as normal.
