The objective of the study was to conduct seismic qualification and fragility testing of a single pole of a 550-kV porcelain disconnect switch. Due to clearance limitations above the shake table, the switch with the main blade in the open position could not be tested in a typical field installation; therefore, several switch configurations were developed for testing. The 550-kV disconnect switch was tested in three configurations: mounted on typical 14-ft-tall supports, mounted on a short 4-in. spacer to simulate flexibility of the top plat es of the supports, and rigidly fixed to the earthquake simulation platform. In the latter two configurations the switch was tested with the main blade in the open and closed positions, and thes e configurations were used for seismic qualification testing of the open-blade switch and in the experimental study for the estimation of the amplification factor.
Triaxial tests of a single pole of the porcelain disconnect switch mounted on elevated supports were conducted by means of an IEEE-compatible time history to determine the dynamic properties and to qualify the switch at the high performance level. The feasibility of seismic qualification testing of tall electrical equi pment with supports removed by introducing an amplification factor due to the supports was also studied experimentally. Triaxial time history tests of a single pole of a porcelain disconnect switch mounted without the tall supports on the simulator platform were conducted to determine the dynamic properties of the pole and to evaluate its seismic response. A seismic quali fication test for the switch in the open-blade position on the earthquake simulator platform (mounted without the tall supports) was performed by using the amplification factor.
The main objectives of the study included static and dynamic testing of switch components (the tall supporting legs and the insulator posts) and determining the feasibility of replacing the blade with an equivalent shorter blade or a concentrated mass for seismic qualification testing of tall
electrical equipment that cannot clear the table. The component testing also included static cantilever tests on the ceramic insulator posts to determine equivalent cantilever loads in failure.
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