Cypoxy® Station Post Insulators Resolve Substation Insulation Problem.

Background

A large electrical utility in the southeast U.S. was experiencing problems with porcelain station post insulators in some of their substations. Power arcs from lightning strikes and animal intrusions were damaging the insulators on disconnect switches and bus supports. Disruptive, costly outages were needed to replace these damaged insulators.

What Did They Do?

Substation maintenance personnel set out to determine if it would be economically beneficial to replace the existing porcelain insulators with S&C Cypoxy Station Post Insulators. They knew that Cypoxy Insulators are superior to porcelain insulators in withstanding power arcs because Cypoxy is self-scouring . . . it maintains full BIL insulation after interruption of an external power arc. They also knew that Cypoxy Station Post Insulators are less susceptible to animal intrusion-related arcs due to a dry arcing distance that is up to 38% greater than that of the equivalent porcelain insulator. Finally they were also aware of the fact that Cypoxy Station Post Insulators had additional benefits over porcelain — lighter in weight, easier to handle, and less susceptible to damage while stored on a truck and during installation.

Estimates were made of the number of porcelain station post insulators changed out annually because of flashovers. Consideration was given to the cost and loss of customer goodwill resulting from the outages needed to replace the insulators, especially in instances where the affected equipment could not be bypassed. After “running through the numbers” it became clear that replacing the existing insulators with Cypoxy Insulators made good economic sense.

Results

The utility was well pleased with the performance of their Cypoxy Station Post Insulators and have further decided to specify Cypoxy Station Post Insulators on all new replacement disconnect switches they procure.