Dynamic qualification of electrical cabinets
The present report deals with the dynamic qualification of electrical cabinets used in energy distribution and telecommunication field (Report No. 3 of Task 6 of Cascade Project). The mechanical loads that can be suffered by an electrical cabinet can derive from the normal operating conditions (i.e. transportation and use) and also from extreme conditions such as the earthquake. These conditions can cause remarkable and costly damages on services and utilities controlled or powered by such equipment. For example, it is not so difficult to imagine the consequences caused by a loss of operating functions of power distribution and monitoring cabinets installed in public utilities, such as a hospital or an electric power generating station. Another example could be the effects deriving from malfunctioning of the telecommunication systems, mainly if they occur during an emergency condition such as that caused by an earthquake. For these reasons, the dynamic qualification of electrical cabinets can become an important step in the risk mitigation. Anyway, as a minimum, it can reduce the direct losses due to equipment damage and additional costs for lost revenue due to service disruptions. The approach to the qualification of electric and electronic boards is faced in this document taking into account the different points of view of all the involved actors, mainly: the Manufacturer, the Qualification Operator and the End User (Industry). A harmonized approach to qualification can provide benefits and cost reduction. Chapters 1 to 3 introduce to the cabinet qualification with general considerations about the product qualification and the main related difficulties. The most widely used Standards are listed and analysed in Chapter 4. Different qualification approaches allowed by the Standards are described in Chapter 5 (i.e., experimental procedures, numerical procedures, mixed procedures and past experience qualification): critical aspects are highlighted and comments and suggestions are provided. Finally, in Chapter 6 a case history of actual qualification processes, based on different approaches, is presented and discussed. The main requirements of the main applicable Standards are reported in the Appendix A, using the same form for all the Standards in order to make easier their comparison. Appendix B lists the most common terms used in the dynamic qualification. The reference documents used in this report are listed in Appendix B.