IEEE C37.98-2013 IEEE Standard for Seismic Qualification Testing of Protective Relays and Auxiliaries for Nuclear Facilities.
protective relay: A relay whose function is to detect defective lines or apparatus or other power system conditions of an abnormal or dangerous nature and to initiate appropriate control circuit action.
NOTE—A protective relay may be classified according to its operating principle or pertormance characteristics.
relay capacity level: The acceleration level in gs used to catalog the seismic capacity of the relay, understood to refer to the required response spectra shape as defined in Annex B. Figure B. 1 and not the zero period acceleration (ZPA) of the test response spectrum.
required response spectrum (RRS): The response spectrum issued by the user or the user’s agent as part of the specifications for proof testing, or artificially created to cover future applications. The RRS constitutes a requirement to be met.
response spectrum (as applied to relays): A plot of the peak acceleration response of damped. single- degree-of-freedom bodies at a damping value expressed as a percentage of critical damping of different natural frequencies when these bodies are rigidly mounted on the surface of interest.
safe shutdowii earthquake (SSE): An earthquake that is based upon an evaluation of the maximum earthquake potential considering the local and regional geology and seismology and specific characteristics of local subsurface material. It is that earthquake that produces the maximum vibratory ground motion for which certain structures, systems. and components are designed to remain functional. l’hese structures. systems, and components arc those necessary to ensure the following:
a) integrity of the reactor coolant pressure boundary’
b) Capability to shut down the reactor and maintain ii in a safe shutdown condition
c) Capability to prevent or mitigate the consequences of accidents that could result in potential off-site exposures comparable to the guideline exposures of 10 CFR-C’hapter I, Part 100
test response spectrum (TRS, as applied to relays): The acceleration response spectrum that is constntcted using analysis or derived using spectrum analysis equipment based on the actual motion of the shake table.
transitional mode: The change from the non-operating to the operating mode, caused by switching the input to the relay from the non-operating to the operating input, or vice versa.
triaxial test: The relay under test is subjected to simultaneous independent acceleration in three orthogonal axes (two horizontal and one vertical).
zero period acceleration (ZPA) (ZPA as dellned by IEEE 3441%L2004): The accclcration level of the high frequency, non-amplified portion of the response spectrum. This acceleration corresponds to maximum peak acceleration of the time history used to generate the spectrum.
zero period acceleration (ZPA) (ZPA, as applied to relays): The acceleration level in gs as shown in Annex 11, Figure B.1.IEEE C37.98 pdf download.