– compatible with modern residual current operated devices
By using the new EMC/EMI filters FN 3268 from Schaffner, you can prevent costly downtimes and lost production caused by accidental tripping of AC/DC sensitive residual current operated devices used in conjunction with frequency inverters.
In paper and wood processing plants, the risk of electrically ignited fires due to ground currents is reduced through the use of 300mA residual current operated devices of type B according to VdS guideline 3501. Residual current operated devices with 30mA release current are used for operator safety in energy-saving drive systems of building services. However, the risk of accidental tripping is increased during operation with frequency inverters, because the physical operating principle of frequency inverters and servo drives generates not only leakage currents with the line frequency, but also undesirable ground currents with the set pulse frequency. This leads to accidental tripping of residual current operated devices, which are unable to distinguish between ground currents and real residual currents.
Standard commercial EMC/EMI filters do not suppress the ground currents of the pulse frequency sufficiently, or may even multiply them many times over due to resonance with the line frequency. The filters become saturated, and the required EMC limit values are no longer maintained. Thus reliable functioning of the safeguard and at the same time compliance with the EMC Directive is no longer possible.
The innovative FN 3268 low leakage current EMC/EMI filters from Schaffner suppress undesirable leakage currents especially in drive systems. They ensure compliance with EMC regulations and support full functionality of AC/DC sensitive residual current operated devices.
The FN 3268 filter series is designed for applications with three-phase frequency inverters and servo drives. The rated voltage is 3x520V with rated currents of 7 to 180A at 50°C ambient temperature. Users of the popular FN 3258 series can convert to the new technology easily thanks to the identical external construction.