Reengineered EMC filters minimize earth leakage currents

TDK CORP. LeaXield active leakage current filter solution minimizes earth leakage currents in converter-based drive systems. Product is designed for applications in variable-speed drives such as those in machine tools, pumps, compressors, conveyance systems, and other pluggable devices. In these systems aggregate earth leakage currents can cause RCDs (residual current devices) to trip at their threshold. As a result, RCDs are either not usable or only with substantial additional outlay. Product is available for load currents of up to 50A at a rated frequency of 50/60Hz and phase-to-phase voltages of up to 520Vac. The active leakage current filter is connected between the RCD and the EMC input filter of the converter in industry-standard three-phase TN power grids and does not require an additional power supply. LeaXield can be utilized for earth leakage currents of up to 1A and can effectively compensate leakage currents over a wide spectral range from 150 Hz to approximately 30kHz.