① There is an external ground wire. If the fault current is large, the ground wire can be temporarily opened for operation. But the monitoring must be strengthened to prevent the floating potential of the iron core after the fault point disappears.
②The manufacturer of the transformer core introduces that if the multi-point grounding fault is unstable, a sliding wire resistance can be inserted in the working grounding wire to limit the current to less than 1A. The selection of the sliding wire resistance is to divide the measured voltage of the normal working ground wire by the current on the ground wire.
③ Chromatographic analysis should be used to monitor the gas production rate at the fault point.
④ After finding the exact fault point through measurement, if it cannot be handled, the normal working grounding piece of the iron core can be moved to the same position of the fault point to reduce the circulating current to a greater extent.