Dependability in electrical power systems exposed to seismic hazard

Dependability is the overall term used for computer systems and is defined as the “ability to deliver service that can justifiably be trusted.” Strong earthquakes can cause serious problems to the dependability of supply of electrical power systems particularly in exposed and sensitive structures as hospitals and strategic buildings. The paper discusses the need to study the requirements for the design and installation of electrical power systems in buildings subject to seismic hazard. Electrical equipment, which are non-structural building components, must be installed in compliance with the seismic requirements contained in current codes and standards. The failure of the building service may in fact depend on the fault of the electrical systems rather than structural collapses. Mechanical and electrical criteria for the design and the installation are recommended to be graduated according to building occupancy categories (as hospitals, strategic buildings). At least three levels of performance are identified for equipment. A special power distribution, “brush-distribution”, has an horizontal structure suitable for the strategic buildings that are at risk for seismic event. Other general design criteria, such as a the service continuity, the system reliability and the system protection, have a special relevance in these appliances.