PWM Frequency, Audible Motor Noise, and EMI - PENN Controls - VFD68Bxx - VFD68Cxx - VFD68Dxx - Three‐Phase Motor Speed Controller - VFD68 Three‐Phase Variable Frequency Drive

VFD68 Variable Frequency Drives Technical Bulletin

PENN Controls
Product name
VFD68 Three‐Phase Variable Frequency Drive
Document type
Technical Bulletin
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Using the default setting (P. 72 = 1, frequency = 1 kHz), electromagnetic interference (EMI) radiation and leakage current from the wiring between the VFD68 drive and the motor is low; however, there is a high level of audible motor noise. As the setting for P. 72 increases (up to P. 72 = 15, frequency = 15 kHz), audible motor noise decreases, while EMI radiation and leakage current increases.

If the audible noise from the VFD is too great with P.72 set to 1, increase the setting to 4 and listen to the audible noise. To minimize the EMI radiation, use the smallest number possible for P. 72.