How to "diagnose" dry current transformers by listening to sounds - News - Global IC Trade Starts Here Free Join

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

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When the dry current transformer is in normal operation, it is very likely to cause a fault due to external factors and other reasons. We can "diagnose" the current transformer by listening to the sound.

1. The current transformer should emit a “嗡嗡” electromagnetic sound during normal operation. If the sound is abnormal, the current meter in the circuit has no indication, and the power meter, electric energy meter, etc. have no indication or the indication is too small. The cause of this anomaly is the secondary side open circuit. Open circuit due to poor contact of the secondary circuit terminals, accompanied by spark discharge.

When the secondary circuit is open, an overvoltage will be generated at its fracture. In severe cases, insulation breakdown may occur, causing grounding or burning of the secondary port. The overvoltage may also cause great harm to the human body. Therefore, the relevant regulations stipulate that the secondary side of the current transformer is strictly prohibited to open.

1. The surface of the dry current transformer has dirt or dust. When it is rainy or cloudy, it will cause “噼啪” discharge sound, and corona may appear. If the discharge is severe, surveillance should be strengthened and a power outage should be requested. When there is a serious discharge sound inside the current transformer, the main reason is that the internal insulation is lowered, causing one discharge to the secondary winding or the core. In this case, you should immediately power off the power.

2. The loosening of the tightening screw and the increase of the vibration amplitude of the iron core will also cause an abnormal “click” sound, and the sound size will change with the load change, and the larger the negative iron core load, the larger the sound. In this case, long-term operation, the current transformer will be severely heated, resulting in insulation aging, resulting in grounding, insulation breakdown and other consequences.