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Editor's Pick


Low leakage filter

27 December 2014

Schurter has expanded its successful range of FMBC NEO 3-phase filters with a low leakage current series for applications where no high leakage currents are allowed. The new FMBC LL series of filters is designed for rated currents between 7 and 180A. It is ideal for leakage current-critical industrial applications such as drive technology.

Today's electrical industrial installations are increasingly being fitted with residual current devices (RCD) to ensure efficient personal protection. This is also a requirement in certain countries for 3-phase systems, for example plug-in systems up to 32A. The RCD limits the current to earth to a maximum of 30mA. This poses a particular problem in drive technology since the frequency inverters that control the engine generate considerable leakage current. Long motor cables further aggravate the problem since they increase the capacity to earth and hence the currents to earth too. The new series of FMBC LL filters helps reduce the leakage currents and permits compliance with common EMC standards as an efficient input filter.

The compact FMBC LL 3-phase filters have been designed for currents from 7 to 180A at an ambient temperature of 50°C. They have UL approvals for ambient temperatures of +50°C as well as +40°C at a higher rated current. The FMBC LL is approved for rated voltages of 520 VAC. This means that they can be used in high-power systems, such as machines used in an industrial environment. Despite their high output performance, they are still compact and lightweight in design.