Electromagnetic/Induction Noise - Delta VFD-VJ Series User Manual

VFD-VJ Air Cooled | 5. Methods of Anomaly Diagnosis

5-9 Electromagnetic/Induction Noise

If there exist noise sources around Hybrid Servo Drive, they will affect Hybrid Servo Drive through
radiation or the power lines, leading to malfunction of control loop and causing tripping or even
damage of Hybrid Servo Drive. One natural solution is to make Hybrid Servo Drive more immune to
noise. However, it is not economical and the improvement is limited. It is best to resort to methods
that achieve improvements outside Hybrid Servo Drive.
1. Add surge killer on the relay or contact to suppress switching surge between ON/OFF.
2. Shorten the wiring length of the control circuit or serial circuit and separate from the main
circuit wiring.
3. Comply with the wiring regulation for those shielded wire and use isolation amplifier for
long wire.
4. The ground terminal of Hybrid Servo Drive must be connected to ground by following the
associated regulations. It must have its own ground connection and cannot share with
electrical welder and other power equipments.
5. Insert noise filter to the input terminal of Hybrid Servo Drive to prevent the noise entering
from the power lines.
In a word, three-level solutions for electromagnetic noise are "no product", "no spread" and "no
receive".
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