Transformers & Switchgear
LV MV HV Bushings 1,000V 11kV 33kV
Webster-Wilkinson transformer bushings are used in transformers as a means of electrical / mechanical connection from the outside of the tank (cables or overhead lines) to the inside of the tank (transformer windings).
There are typically 3 types of major insulating material used in electrical equipment bushing manufacture.
Porcelain insulation is a proven technology providing a low cost, long life and maintenance-free solution. It is able to withstand all environmental conditions. Porcelain insulators are normally supplied with brown glaze but grey glaze can be provided if required. For a given operating voltage porcelain insulators can be provided with varying creepage distances depending on environmental conditions.
Cast resin insulation is typically used in bushings rated at 12kV and below. Resin provides advantages over porcelain, as complete bushings can be produced faster and meet more demanding dimensional tolerances.
Composite insulation is useful in applications of high vibration and possible urban vandalism due to its natural flexibility and ability to withstand impacts.