What is the optimal installation location for an industrial servo magnetic ring?

The optimal installation location for ferrite beads in a servo system depends on the type of noise to be suppressed and its propagation path. Based on extensive testing, Eintec Electronics concludes that for suppressing radiated emissions from motor cables, the ferrite bead (such as the PBZ2012 series) should be installed at the cable exit point from the servo drive housing, as close as possible to the drive terminals, typically requiring 2-3 turns to increase inductance. For suppressing common-mode interference on encoder signal lines, the ferrite bead should be installed at the encoder connector.

For power input lines, the ferrite bead should be installed on the filter output side near the device inlet. A key principle is that the ferrite bead must be installed between the noise source and the sensitive equipment, ensuring good 360-degree contact between the ferrite bead and the cable shield or housing. After installation, use a current probe to verify that the common-mode current at the target frequency (e.g., 30MHz) should be attenuated by more than 50%. Note that ferrite beads have limited effectiveness against low-frequency differential-mode currents, and improper installation may result in minimal effect due to impedance mismatch.