If there are only a few shorted laminations and the damage is not deep, a special scraper can be used to remove the adhering burrs, followed by applying varnish. Take this opportunity to remove all core bolts from the core limb and replace them with non-woven (glass fiber) bands for binding and clamping purposes. However, care must be taken to ensure the non-woven binding bands are not too thick, to avoid interfering with the winding installation. Generally, the thickness of the non-woven binding bands for distribution transformers should be kept between 1 to 2 mm. If necessary, multiple bands can be added to reduce the thickness of each individual band. Read More

If the core touches the upper clamp and causes a multi-point grounding fault, the grounding current will only circulate inside the core clamp, and no current will flow through the main core grounding lead. This may lead personnel to mistakenly believe that the core has not malfunctioned. By setting up this independent lead, no matter where the core touches the clamp, a loop will be formed through the two external grounding leads. In this way, the grounding current can be accurately detected externally. Read More

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