Insulation Contact Box Shielding

Insulation Contact Box need to meet the withstand voltage requirements, but for the 40.5 kV contact box, the 12kV contact box is enlarged, and epoxy resin alone is not enough. The distance between the mounting steel plate and the contact arm is too small, and the electric field strength is very high. Discharge and breakdown will occur between the contact arm and the mounting plate. Increasing the air distance has limited effect on improving insulation and reducing the electric field strength. Miniaturization does not allow the air spacing to be too large. Therefore, a shielding net made of metal or semiconductor materials is added. On the inside of the contact box, the circular shielding net is high voltage, and the outer shielding net is grounded. The echoing circular rings form a capacitor between the contact arm and the grounded steel plate. Epoxy resin, as a capacitor medium, can absorb very high voltage, which can greatly improve the insulation withstand level of the contact box.