Frequency converters are widely used in many fields. During operation, frequency converters often encounter interference with DCS signals. So, what measures can effectively address this interference problem? Below, we'll introduce some specific solutions.
Proper wiring
To significantly reduce the strength of interference signals, control lines of various devices should be kept as far away as possible from the input and output lines of the frequency converter during wiring. Spatially, control lines should ideally cross the input and output lines of the frequency converter, preferably perpendicularly.
weaken the source of interference
Integrating reactors or filters is costly for low-power frequency converters. We employ a low-cost electromagnetic interference suppression method: passing the motor cable through a ferrite ring increases the impedance of the conductor at the point of passing through, thus blocking electromagnetic interference current. The total inductance and impedance increase with the square of the number of turns as the conductor is wound around the ferrite ring. The motor cable can be passed through the ferrite ring three times. However, it should be noted that the grounding wire connecting the motor and the frequency converter should remain outside the ring.
Shield the line
The connection cable between the frequency converter and the motor should be run through a metal conduit if possible, and the metal conduit should be grounded. Whether the signal cable shield is connected to the common terminal or grounded, it should only be connected at one end; never both ends.
Accurate grounding
The grounding wire should be as thick as possible, and the grounding point should be as close as possible to the frequency converter; the grounding wire should be as far away from the power line as possible; the grounding wire used by the frequency converter must be separate from the grounding wires of other equipment; it is absolutely necessary to avoid connecting the grounding wires of all equipment together before grounding; the grounding terminal of the frequency converter must not be connected to the neutral wire of the power supply.
