Oil to Air Condenser Bushing
Oil to air condenser bushings are typically utilised for fluid insulated transformers. Bushings ensure electrical current passes through the casing without raising the voltage potential of the material through which it is passing i.e. the casing/wall does not become ‘electrified’.
3D Model Components (Summary)
The 3D model cross section shows all major components, these include:
- Outdoor Terminal
- Top Cap
- Air Vent
- Oil Level Indicator
- Oil Expansion Chamber
- Insulating oil
- Porcelain Insulator
- Oil Impregnated Condenser Core
- Test Tap
- Mounting Flange
- Stress Shield
3D Model Components (Detailed)
The connection terminal connecting the bushing to the grid.
An air vent or pressure relief device may be fitted here; this particular model has no such device.
The top cap houses the oil expansion chamber and oil level gauge. It also houses the spring used to maintain a constant pressure on the gasket between the top cap and porcelain insulator.
Oil Expansion Chamber
An expansion chamber to allow for oil expansion and contraction due to changing temperature.
Due to thermal expansion and contraction, a spring is required to maintain pressure on the sealing gasket. Constant pressure on the gasket must be maintained in order to prevent oil leaks, moisture ingress or particle ingress.
A gasket used to seal the top cap and porcelain insulator. A constant pressure is maintained on the gasket using a spring.
Oil is used as an insulating medium between the conductor and external components.
Designed to prevent leakage current reaching the grounded item e.g. transformer. The insulator has a large surface area to aid natural cleaning by wind and rain. The large surface area and ribbed shape also provide a comparatively long path to earth.
Oil Impregnated Condensor Core
The oil impregnated paper core is interlaced with conductive material, this arrangement creates a series of capacitors.
The flexible cable from the transformer is passed through the conductor. The conductor also allows the spring pressure to be transferred to all joints and gaskets.
A tan delta/power factor/dissipation factor test can be performed here in order to assess the condition of the condenser core.
A flange connecting the bushing to the transformer casing.
Current Transformer Extension
A current transformer can be installed here if required.
Oil Side Porcelain Insulator
This section of the porcelain insulator is submerged in oil.