The high-voltage wall bushing is suitable for the insulation and support of conductive parts through walls or other grounding materials in power distribution units and high-voltage electrical appliances of power plants with AC voltages of 35kV and below. The casing is suitable for ambient temperatures of -40 to +40 ° C and is not suitable for use in conditions where the performance of the casing is sufficient to reduce the surface condensation of the casing. When the casing ambient temperature is higher than +40 ° C, but not more than +60 ° C, the operating current of the bushing is recommended to increase by 1 ° C per ambient temperature, and the rated current load is reduced by 1.8%. When the casing ambient temperature is below -40 ° C and the maximum allowable heating temperature specified in Clause 5.1 of GB 12944.1 is used, the operating current is allowed to be overloaded for a long period of time. It is recommended to increase the rated current load by 0.5% for every 1 °C decrease in ambient temperature, but the increase should not exceed 20% of the rated current.
According to the place of use, the casing can be divided into five types: indoor ordinary type, outdoor one indoor ordinary type, outdoor one indoor pollution resistance type, outdoor ~ indoor high prototype, outdoor one indoor plateau pollution resistance type.
The indoor general type is generally applicable to indoor areas where the installation location does not exceed 1000m.
The general type of outdoor household is generally applicable to the installation site where the altitude is not more than 1000m, but the installation location should be no obvious pollution area.
The outdoor pollution resistance of one household is suitable for the installation site with an altitude of no more than 1000m. For 35kV casings for severe and heavy pollution areas, 63kV oil-paper capacitive wall bushings are available.
An outdoor high prototype is suitable for installations with an altitude of 3000m or less.
The outdoor pollution resistance type of one indoor is suitable for the dirty area below 3000m in the installation location.
The casing can be divided into three types according to the conductor material used: aluminum conductor, copper conductor and conductorless (busbar type).