Cost optimal surge protective system for low voltage installations

Abstract

Surge protective devices (SPDs) have become an integral part of residential, commercial and industrial power quality applications. A wide selection of surge SPDs are promoted by greater number of manufactures for the protection of electrical and electronic systems damaging effects of electrical transients and lightning. The selection of the appropriate cost effective SPD is great difficult due to some manufactures use different technologies and many manufactures specify their SPD performance differently. One of the difficult tasks encountered when specifying a SPD is identifying and understanding the ratings associated with its application. There are many performance values and ratings associated with an SPD, such as Maximum Continuous Operating Voltage (MCOV), Voltage Protection Rating (VPR), Nominal Discharge Current (In), and Short Circuit Current Rating (SCCR). The most important and misunderstood rating is the Surge Current Rating. In today’s market there are numerous SPDs with surge current ratings ranging from 10 kA through 1000 kA with different prices. The research presents a methodology to select cost optimal surge protection devices for low voltage installations. The procedure for the selection of SPD is considered the steps of risk assessment, IES standard, manufacture technical details, the applied technology and the data bank of SPD available in local market. The cost optimal solution has been obtained by user friendly software considering the risk assessment result, area lightning density, location and the geographical factors.