AC Motor and VFD Selection Guide

AC Motor shall be selected according to the type of Load & Application with the kind of cooling for the motor needed and after selecting the motor & identifying the application requirement in terms of torque, you can select various VFDs available in the market for specific applications pertaining to your requirement in different brands.

Do go through their product catalogs once or ask the dealer or manufacturer to suggest you one as per your application and ratings of motor in terms of either HP or KW mentioning constant torque or variable torque requirements, good dealers or manufacturers will suggest you their specific model as per your application.

If you are not suggested by them for the right model or you are not satisfied by their advice then straight away look for General Purpose VFDs in their catalog and select one higher or equivalent rating variable frequency drive for your application.

As a thumb rule, it is 1.5 times AC motor rating with same RPM. But truth is we must match Torque speed Curves and give close look at Peak Operating Torque of DC motor and duty cycle. Once AC motor is selected, VFD can be chosen based on AC motor ratings and application duty.