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chainflex® motor and servo cables enable variable frequency drives to operate safely and failure-free

Tech Talks by igus helping solve design engineering problems with motion plastics

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tech talk Learn more at enable variable frequency drives to operate safely and failure-free Customers are demanding variable frequency drives (VFD) that are more compact and that come equipped with higher-power motors and more accurate frequency converters. Because of this, the user must consider the electrical characteristics of the system's motor or servo cables to ensure the entire VFD system functions properly. In this tech talk, you will learn about the appropriate insulation material you'll need for your electrical cables, changes happening within the market, and a new product from igus ® that enables modern VFDs to operate safely without failing. Properties of electrical cables Every electrical cable has a certain inductance, capacitance and ohmic resistance depending on its structure and the materials used. The cable's ohmic resistance in an industrial environment depends mainly on the conductivity, cross section and length of the conductor. The capacitive values, on the other hand, are strongly dependent on the insulation material. Therefore, two identical cables with the same length and cross section will have completely different capacitive specifications if their insulation material is not the same. Replacement circuit diagram for a cable element of a two-wire cable of length dx. For a required length, L´ = Inductance, R´= Resistance, G´= Dissipation factor and C´= Capacitance are used for simplicity. Proper insulation material as a central factor for capacitance Today's generation of VFDs change their speeds by changing the frequencies of the drive voltage. If a high- capacitance cable is used, a significant amount of energy is lost for the capacitance of the cable alone. In the worst-case scenario, this could lead to unwanted reflections and voltage overlaps. Many power, motor and servo cables are made with polyvinyl chloride (PVC) insulation because it is cost- effective and easy to process. However, PVC has an extremely high dielectric constant (εr). A higher εr increases the cable's capacitance, requiring more energy to change and discharge the cable. This leads to higher losses and higher switching inaccuracies within the overall system. Safe and reliable cables for high-frequency drives igus ® has been offering chainflex ® motor and servo cables made of high-performance polymers for more than 15 years. These polymers have a lower εr and a high electrical resistance. The cables have been Chainflex ® motor and servo cables dL dR dG dC

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