SEISMIC IDENTIFICATION PLATE FOR THE GSU TRANSFORMER

[subash148]

Dear Forum Members,

My GSU transformer specification mentions that the " The transformer is required to demonstrate design and construction suitable for Seismic Zone 3, in conformance with IEEE Standard 693-2005."

The section 1.3 of IEEE Std 693-2005- IEEE Recommended Practice for Seismic Design of Substations mentions " If any part of this recommended practice is removed, not met, or reduced, then neither the user nor the manufacturer may claim the equipment is in compliance with IEEE Std. 693 and should not attach the seismic identification plate to the equipment."

Say the transformer is designed and constructed as per the IEEE Standard 693-1997. Does the manufacturer require to provide seismic plate to the transformer? Also, what kind of seismic information is required to be displayed on the seismic plate?

SG

 

[prc]

Seismic qualification identification plate shall be designed and attached as per Clause A8 of IEEE 693. 1997&2005 editions are having same type of plate, except the year of standard. I believe it is not the plate that is important, but whether sufficient analysis/tests were done as per the requirements of the standard.

Earlier there was a standard C57.114-1990 Seismic Guide for Transformers and Reactors. This was withdrawn in 1996 and the requirements were added in 693-1997 as Annexure D. Since large transformers weigh anything between 50-500 tonnes, static and dynamic stress analyses are done to prove the seismic withstand strength. Bushings ,most critical are subjected to tests as described in standard. Special mounting provisions are made on foundation to avoid the slipping out of transformer. Years back, these were all that I did, when I had to satisfy a US customer.

 

[subash148]

Thanks PRC. This definitely clears my doubt.
SG