scope:

Introduction. This standard specifies the procedures to be used in the seismic testing of relays used in power system facilities. The standard is concerned with the determination of the seismic fragility level of relays and also gives recommendations for proof testing.

Purpose. The purpose of this standard is to establish procedures €or determining the seismic capabilities of protective and auxiliary relays. These procedures employ what has been called fragility testing in ANSI/IEEE Std 344- 1975, Recommended Practices for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations. In order to define the conditions for fragility testing of relays, parameters in three separate areas must be specified. In general they are:

(1)T he electrical settings and inputs to the relay, and other information to define its conditions during the test.

(2) The change in state, deviation in operating characteristics or tolerances, or other change of performance of the relay which constitutes failure.

(3) The seismic vibration environment to be imposed during the test.

Since it is not possible to define the conditions for every conceivable application for all relays, those parameters, which in practice encompass the majority of applications, have been specified in this standard. When the application of the relay is other than as specified under any of (1)(,2 ), and (3), or if it is not practical to apply existing results of fragility tests to that new application, then proof testing must be performed for that new case. The use of these capability data will assist in the selection of relays. One number will be used to catalog the seismic capability of a relay. This number is the zero period acceleration level; and is understood to refer to the standard response spectrum shape as defined in this standard. The capability data will help designers of generating stations, substations, and various other power system installations to incorporate the seismic capabilities of the relays into the overall design of these facilities.

Limitation of Test Results. This standard applies only to the testing of protective and auxiliary relays and does not apply to switchboards, panels, or any structure upon which the relay may be mounted. It is the responsibility of the power system facility designer to combine data on the seismic performance of the relay mounting structure and the relay to arrive at an acceptable equipment design.