IEEE C37.82-1987 pdf free.IEEE Standard for the Qualification of Switchgear Assemblies for Class 1E Applications in Nuclear Power Generating Stations.
IEEE C37.82  loading shall be estimated for the application. The qualified life of switchgear components is dependenton the average loading.Considering duty and available power distribution options in nuclear Class 1E systems, theaverage loading rarely, if ever, approaches the continuous current rating of the equipment.
The maximum short-circuit current shall be specified for the application.
In order to provide a basis for qualified life demonstration, circuit breaker mechanical operations shall be specified.Acumulative number of mechanical operations not greater than that corresponding to two maintenance intervals, asdefined in applicable circuit breaker standards, is considered usual.
lt is considered usual that the mechanical loads from incoming cables,conduits,other interfacing hardware,orequipment such as transformers are separately supported or isolated so as not to impose significant mechanical loadingon the switchgear assembly structure.When switchgear assemblies are applied where the service conditions are not within the range given as usual serviceconditions, the applicable service conditions shall be specified and the switchgear assemblies shall be qualified forthese conditions. Where qualification to unusual conditions becomes impractical，improvement of the serviceconditions may be necessary.The DBE that usually applies to switchgear assemblies is a seismic event. Other DBEs，such as the severeenvironmental conditions associated with a loss-of-coolant accident and high-energy line break, are not normallyapplicable.
Due to the seismic variations between sites and building structural differences, seismic loading in the form of requiredresponse spectra shall be specified for each switchgear assembly application.The switchgear assemblies shall bequalified in accordance with ANSI/IEEE Std 344-1975[20].
If DBEs or unusual requirements in addition to the seismic event are applicable to switchgear assemblies, detailedconditions shall be specified and considered.This document describes the methods and requirements for qualifying switchgear assemblies for indoor areas outsideof the containment in nuclear power generating stations. IEEE C37.82 pdf download.