Common mode chokes (CMCs) are mitigating devices commonly used in VFD applications to reduce EMI interference. A common-mode choke is an inductor with the three-phase conductors wound in the same direction through a common magnetic core, typically toroidal in shape.
When used on VFD output cables it provides a high impedance to any line-to-ground capacitive noise current generated during the fast transition time of the output voltage waveform and does not affect the line-to-line power circuit and takes up less physical space. In contrast, the phase-conductor inductance of a load reactor reduces motor phase voltage (i.e. voltage drop) thus lowering the available motor output torque.
CMC provides both common mode and differential noise attenuation and reduction of PWM VFD voltage overshoots which degrade motor insulation and affect bearings.
Available from 10-280A, 600V in IP20. 16kHz switching frequency.
CMC range 10 to 280A for VFD applications
Brochure with specifications
Common mode choke brochure click above
Sentinel Power Quality has the knowledge and experience
When applied correctly, filters are an important tool in the harmonic mitigation toolbox. However, no form of mitigation is perfect. The secret of success is recognising the pros and cons of all types of active and passive mitigation and being able to apply the most appropriate form of mitigation for any given application.
The engineers at Sentinel Power Quality have been involved in applying active and series passive filters since 2003 to standard and demanding applications.
Contact us with your application details and let us assist you.