Development Trend of Residual Current Circuit Breakers

by : Mitja KoprivĂ…?ek - Eti d.d.

The paper deals with the directions of the state-of-the-art changes in the field of residual current circuit breakers, with particular emphasis on standards changes due to new requirements of environment, reliability of operation, operation at high frequencies, and use of voltage-dependent switches.

Protection switches, or residual current devices are in practice a widely used way of protection against indirect contact with live system parts, fire, and direct contact with live components, in various types and installation executions. The following types of installations can be distinguished: housing and similar installations, and industrial installations. And the executions refer first of all to the earthing systems, i.e. TT, TN and IT systems. The field of use of residual current devices is therefore wide and important enough to have to permanently follow the development. The state-of-the-art is defined by the state of standardization, therefore the paper gives in the first place an analysis of standards, with an emphasis on the IEC, EN and SIST standards, and the terminology usually used for individual product is added, too. In the continuation the actually usual use of residual current devices has been represented. The central part of the paper is dedicated to the development trend of these products, where the changes in market requirements should be emphasized, and as a result also the requirements for changes in the standardization area.