KEMA Labs seismic tests on GE bushing Oil-to-Air 345 kV

KEMA Labs has recently tested the bushing Oil-to-Air 345 kV by GE in our High voltage Structural Laboratory in Milan, Italy. The client’s bushing went under seismic test as per IEEE 693 .

In particular, the tested object was mounted on a frame reproducing the operating condition, with a 45-degree inclination. Furthermore, a triaxial seismic test with a Zero Period Acceleration (ZPA) of 2 g in both horizontal directions and 1,6 g in vertical direction was carried out and, as required by the standard, recorded acceleration signals placed at the top of the bushing have been processed (through the double integration method) to obtain maximum displacements during seismic test. Strain gauges for measuring stress or bending moment at the base and accelerometers have been used on the bushing in order to check the capability of withstanding the required seismic event.

The results achieved in our laboratory demonstrate the capability of the bushing to withstand high level performance seismic test required in IEEE 693 standard.

The customer chose KEMA Labs ( CESI Testing, Inspection and Certification Division) due to our long track record and deep range of skills , as well as a portfolio of pollution and salt fog test facilities, which include one of the biggest salt fog chambers ever built (which can test up to 600 kV DC and AC). In particular, the High Voltage Structural Laboratory in Milan operates with a 6 degrees of freedom 4×4 m MultiAxes Shaking Table for Earthquakes Reproduction (MASTER) shaking table for seismic qualifications. In addition, a multi-channel digital system (32 channels/16 bits) controls and records all signals.

As seismic events can affect integrity of these apparatus, the seismic qualification is required by international standards. Therefore, GE trusted KEMA Labs to offer our services for their test object.