Cap and Pin Type Bus Support

[sambapati]

Recently we have a failure on the 34.5kV cap and pin bus support on our substation. The substation is already old (more than 25 years old) and we read thru posts in the internet that the porcelain cap and pin type insulators are already being being replaced by other utilities due to their design defects i.e., cement, metal and porcelain combined. Our research shows that our option is an exact replacement and we found 2 suppliers e.g., NGK and Victor USA having this type of insulators. However, they are also porcelain and we would like to replace it using a polymer type to increase the creepage distance. The replacement insulator should be TR 49 compliant. Can anybody else recommend other suppliers? Please identify also the Model No. or catalog no so that it can be verified.

 

[wbd]

Try Lapp Insulator and Ohio Brass (AB Chance/Hubbell)

 

[ehanes75]

The Utility Co I work for has not had good experience with silicone polymer insulators, especially in high contamination areas such as near the sea...we only get about 5-10 years out of them. They perform better in inland areas with low or moderate contamination. Have you considered porcelain post-type insulators? For additional contamination resistance porcelain can be coated with spray-on RTV silicone rubber compound.