High Voltage Wall Bushing

Power Station type high voltage wall bushing is suitable for use in power stations, substations and electrical equipment of 35kV and below, for the conductor (busbar) to pass through the grounding partition, walls and closed distribution institutions as insulation support and external conductor (busbar).
The high-voltage wall bushings for power stations are divided into two series: indoor and outdoor, with copper conductor wall bushing, aluminium conductor wall bushing and busbar wall bushing without conductor.

Due to the large number of products, the products are listed separately for the convenience of users. The anti-pollution series is divided into two categories: creepage distance below 2.0 cm/kV and creepage distance above 2.5 cm/kV. Creepage distance of 2.5cm/kV and 3.1cm/kV are particularly recommended. Not only becasue their outdoor end is highly resistance to pollution, but the creepage distance of the indoor end also has been increased as much as possible to prevent flashover due to condensation etc.

The performance of high-voltage wall bushing conforms to the provisions of GB12944.1-91 Technical Conditions for High-Voltage Wall Bushing and GB12944.2 Dimensions and Characteristics of High-Voltage Wall Bushing.

Main Technical Parameters

Model Meaning

C – indoor copper conductor wall bushing.
CL – Indoor – aluminium conductor wall bushing.
CWL – outdoor – indoor aluminium conductor wall bushing
CB – Indoor – round conductor ceramic wall bushing.
CWB – outdoor – indoor round conductor ceramic wall bushing  ;
B – bending damage load rating, 7.5kN.
CLB – indoor aluminium conductor wall bushing (reinforced)
CWLB – outdoor – outdoor aluminium conductor wall bushing (reinforced)
CW – outdoor – indoor copper conductor wall bushing
CWWL – Outdoor – Indoor anti-pollution aluminium conductor wall bushing
CWW – Outdoor – Indoor anti-pollution copper conductor wall bushing
CM – Indoor busbar wall bushing
CMW – Outdoor busbar wall bushing
CMWW – outdoor – indoor anti-pollution copper conductor wall bushing
Example: Model CWWL-35/630-3
35kV, 630A current, outdoor and indoor anti-pollution aluminium conductor wall bushing , suitable for class 3 fouling area.
Example: CWWL-35/630-1-G
35kV, 630A, outdoor-indoor highland anti-pollution aluminium conductor wall bushing for class 1 foul areas.
Example: Model CWWB-35Q/630
35kV, 630A, large creepage distance copper conductor wall bushing

Working Conditions

1. The bushing is suitable for use in ambient temperatures from -40°C to 40°C. It is not suitable for use under conditions that would reduce the performance of the casing or in the case of condensation on the surface of the indoor part of the casing.
2. When the ambient temperature of the bushing is above +40°C, but not exceeding +60°C, it is recommended that the rated current load of the bushing be reduced by 1.8°C for every 1°C increase in ambient temperature.
3. When the bushing is used at an ambient temperature higher than +40°C and in accordance with the maximum permissible heating temperature specified in GB12944.1, Article 5.1, the operating current is allowed to be overloaded for a long period of time, and it is recommended that the rated current be reduced by minus 0.5% for every 1°C decrease in ambient temperature 0.5%, but the increase should not be greater than 20% of the rated current.
4. The bushings can be divided into five types according to the place of use: indoor common type, outdoor-outdoor common type, outdoor-indoor anti-pollution type, outdoor-indoor plateau type, outdoor-indoor plateau anti-pollution type.
   The indoor general type is generally suitable for installation sites up to 1000m above sea level, but the installation site should be free of obvious dirt.
   The outdoor and indoor anti-pollution type is suitable for dirty areas where the installation site does not exceed 1000m above sea level. For 35kV casing in severely and heavily fouled areas, 63kV oil-paper capacitive wall bushing can be used.
   The outdoor and indoor plateau type is suitable for installation sites up to 3000m above sea level.
   The outdoor and indoor plateau type is suitable for installation in dirty areas with an altitude of 3000m or less.