In 2015 two 230 kV RIF® bushings were seismically qualified by shake table testing according to IEEE 693-2005. This testing was performed at the Structural Engineering & Earthquake Simulation Laboratory (SEESL) at the University of Buffalo. The test samples were two identical 230 kV RIF® bushings. One bushing was tested for the normal IEEE 693-2005 High Performance Level. To cover a possible future IEEE 693 requirement the second bushing was tested to 2.5 times the IEEE 693-2005 performance level with an extended plateau (15.5Hz) for the High Performance Level. The results of the testing were certified by WEGAI, qualifying the bushing for the IEEE 693-2005 High Performance Level.
In 2022 RHM International asked WEGAI to re-certify the 230 kV RIF® bushing design for the IEEE 693-2018 High Performance Level based on the 2015 shake table with extended plateau test results. The WEGAI review concluded that the IEEE 693-2018 requirements for pre-test functionality testing, static pull testing, pre-test resonant frequency searches, 2.5 times 1.0g time history with extended plateau shake table testing and post-test visual inspection and functionality testing were all met in the 2015 tests and that the 230 kV RIF® bushing could be seismically qualified according to IEEE 693-2018. In addition, since the 230 kV RIF® bushing design is considered the most seismically vulnerable configuration and according to IEEE 693-2018 Section 4.7 all RIF® bushing designs less than 230 kV can also be considered as seismically qualified.
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Shake Table Test Set-Up – 230 kV RIF Bushing
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TRS vs. RRS IEEE High Performance Level Extended (2.5g ZPA)