Cap And Pin Insulator Failures

To ensure the desired performance of an electrical insulator that is for avoiding unwanted insulator failure each insulator has to undergo numbers of insulator test.

Cap and pin insulator failures. The leakage current that flows through the surface of. The corrugation increases the creepage length so consequently increasing resistance to the insulator leakage current. In typical failures that occur naturally the primary failure is degradation of the cement. In some cases failure will result in complete loss of service as in separation of the cap from the pin or breakage of the fiberglass core rod in both cases with dropped conductors.

The situation becomes more complicated when an insulator fails electrically but not mechanically. The background of the problem and the design concepts which resulted in this new product line may be found in victor s product brochure cap and pin replacement insulators which is available from our agents or directly from the factory. Since that time similar failures have occurred on 12 47 kv 34 5 kv 41 8 kv and 69 kv bus installations at many other locations. Causes of insulator failure.

Mechanical failure of a composite insulator a glass or porcelain cap pin or a porcelain long rod insulator will in all cases cause a drop of the conductor if no other insulator is utilized in parallel. In the case of a puncture the arc passes through the body of the insulator. Between the socket cap and the pin of each porcelain insulator. After a period of time and expansion and contraction.

Every porcelain insulator has a porcelain shell and cement between the cap and the pin. The electrical failure of insulator occurs either by puncture or flashover. In other cases less serious failures might occur such as partial damage to discs or housings or shattering of the glass shell which has no immediate. These failures which are apparently due to cement.

The corrugation below the insulator is for the purpose of obtaining longer creepage path between the pin and cap. The pin of the insulator damaged the insulator thread. Failures of pedestal type pin and cap insulators the problem of failure of pedestal type insulators first appeared on a 34 5 kv bus at a reclamation substation in 1962. Before going through testing of insulator we will try to understand different causes of insulator failure because insulator testing ensures the quality of electrical insulator and chances for failure of insulation depend upon.

Insulator failures an overview. The flashover is caused due to the arc discharge between the conductor and the earth through air surrounding the insulator.