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Description / Abstract:
Purpose. The purpose of this standard is to
establish procedures for 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 IE
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) The 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 tocatalog 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.