Soft starter or variable-frequency drive?

The advantages and disadvantages of each in various applications

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Can you talk about the pluses and minuses of using a soft starter or an ac variable-frequency drive (VFD), as well as explaining the applications in which one might be a better fit than the other?Greg Maryniarczyk, test engineer at DLS Electronic Systems: Soft-start drives are used to limit inrush current associated with electric motor startup. Soft-start drives lower the initial voltage by adding solid-state series impedance and ramp up until full speed is achieved. Doing this extends the life of the motor and mechanical components that are connected to it. Large motor electric inrush current also places a high demand on the electrical supply system, which often results…

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Voices: Real Answers

Should I limit programming to ladder logic or use all standards within IEC 61131?

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