Changes to the 2020 NEC include the addition of several paragraphs in section 430.122. These changes will help the user to determine the correct ampacity for conductors used with power conversion equipment. The Adjustable Speed Drive is one type of power conversion equipment that provides a means of adjusting the speed of an electric motor, 100. A Variable Frequency Drive, VFD, is an adjustable speed drive that controls the speed, the RPM, of a motor by controlling the frequency and voltage supplied to a motor. The changes made in 430.122 Conductors – Minimum Size and Ampacity apply to Adjustable Speed Drive Systems.
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