VLT® Common Mode Filters MCC 105

Reduce electromagnetic interference and eliminate bearing damage by electrical discharge

VLT® Common Mode Filters MCC 105 (HF-CM) cores are special nanocrystalline magnetic cores which have superior filtering performance compared to regular ferrite cores. They act like a common-mode inductor (between phases and ground).

Installed around the three motor phases (U, V, W), they reduce high-frequency common-mode currents. As a result, high-frequency electromagnetic interference from the motor cable is reduced. However, the core kit should not be used as the sole mitigation measure, and even when the cores are used, the EMC installation rules shall be followed.

Prevent motor bearing currents

The most important function is to reduce high-frequency currents associated with electrical discharges in the motor currents. These discharges contribute to the premature wear-out and failure of motor bearings. By reducing or even eliminating discharges, the wear-out of the bearings is reduced and the lifetime extended. Thus, maintenance and down-time costs are lowered.

Ideal for retrofitting 

Bearing current problems are most often discovered after commissioning. Therefore, the cores have an oval shape which makes them ideal for retrofitting and for installation in restricted places.

Only 5 variants cover the entire VLT® product range making it possible to carry these valuable aids in a service tool kit.

HF-CM selector

The cores can be installed at the frequency converter’s output terminals (U, V, W) or in the motor terminal box. When installed at the frequency converter’s terminals, the HF-CM kit reduces bearing stress and high-frequency electromagnetic interference from the motor cable. The number of cores depends on motor cable length and frequency converter voltage.

Product range 

Available for all power sizes from 0.18 kW to 1.4 MW
 5 core sizes cover the entire VLT® power range