**********
Want more high-quality educational engineering videos? Click on the link below to view our online video courses.
Hope to see you on a course soon!
**********
Like this video? Check out some of our FREE engineering Apps!
**********
You can read more about electrical bushings in our 3D technical encyclopaedia:
**********
Want to use this 3D model in your training course or lesson? Simply join saVRee!
**********
Introduction
Electrical bushings allow live conductors to be passed through grounded partitions, walls, or tanks etc. without raising their electrical potential (voltage). They perform this task by insulating the central conductor.
The example used in this video shows a 3D animation of an oil insulated porcelain solid/bulk bushing; this bushing is often used with electrical transformers (hermetic and conservator type). Another common bushing design type is the condenser/capacitance graded bushing.
Bushings are commonly seen at substations, power stations and generally in the power engineering industry (generation, distribution and transmission of electricity). Bushings may be of various designs, but are roughly split into two main designs, the bulk/solid type, and the condenser (capacitor grade) type.
The 3D model used in this video was loaded through a web browser at saVRee.com.
How Electrical Bushings Work
Electrical current flowing through a conductor will create a magnetic field and an electric field. The magnetic field is of little interest concerning bushings, but the electric field is. The electric field strength increases as the voltage potential increases. A higher voltage potential will always try to flow to a lower voltage potential e.g. ground. Bushings prevent this by insulating the conductor from the grounded component through which it passes.
Bushing Components
A bushing consists of a conductor, terminals and some form of insulator. The insulator chosen in this video is manufactured from porcelain.
Mineral oil is added to a void space surrounding the conductor and it also acts as an insulator.
To aid with keeping the bushing clean and to maintain resistance on the creepage path (leakage path), rain sheds are used.
The porcelain body is hot glazed as this puts the porcelain under compression stress, which makes it stronger mechanically. Porcelain is weak when tensile stress is applied. The glaze also helps keep the bushing clean.
Electrical arcing horns will be discussed in the bushings course (visit saVRee.com for more info).
0 Comments