Bushing of Transformer

 

Bushing of Transformer ( for H.V side and L.V side )

The Bushing of power transformer is a type of porcelain or ebonite post insulator put on the top or side of the transformer tank through which connections are made to the external circuit.

The types of bushing are as follows:-

1. Porcelain insulator bushing used upto 11 KV.
2. Oil filled bushings consisting of a hollow porcelain cylinder of special shape with a hollow tube shaped conductor through its centre used for the voltage above 33 KV.
3. Capacitor type bushing made of thick layers of bakelized paper alternating with thin graded layers of tin foil being covered by a porcelain rain shed and filled up with bitumen in the annular space between the rain shed and the bushing used in outdoor sub-station for the voltage above 33 KV.