When the transformer is operating normally, there is an electric field between the live winding and the fuel tank, and the transformer metal sheet and other metal components are in the electric field. Since the capacitance is unevenly distributed and the field strength is different, if the transformer metal sheet is not grounded, charging and discharging will occur, and the insulation strength of the solid insulation and oil will be destroyed, so the transformer metal sheet must be grounded.
When the transformer metal sheet is grounded, a grounding lead wire of the iron yoke clip is separately set. After the setting, no matter where the transformer metal sheethits the clamp, the two grounding outer leads form a loop, so that the external can be detected correctly. Ground current.
The grounding piece is placed in the middle of the cross section of the iron yoke, so that no matter where the iron yoke pulls the insulating bolt and where the fault grounding point is, the induced voltage of the circuit is only 1/4 of the 匝 voltage, and the ground current is only A few amps are much smaller than when the transformer metal sheet grounding piece is placed in other positions. If it is necessary to place the transformer metal sheet grounding piece in other positions due to problems such as inconvenient installation on site, the insulating bolt of the yoke pull strap and the grounding piece should be placed diagonally to prevent large currents from being generated.