6 Factors You Must Look Into When Picking a Variable Frequency Drive

If your industrial unit utilizes AC induction or synchronous motors, then you definitely know the importance of controlling the speed of the motor so as to reduce the energy consumption during non-peak load times.

This is where variable frequency drives (VFDs) play a big role in industries in the present times, as they are used to control the speed in accordance to the requirement of the motor and output. But how do you find the right VFDs that specifically meet your application requirement and provide you with maximum energy efficiency and enhanced durability of the motor? We help you with some key factors:

There are two types of application types you will find when considering variable frequency drives. One is Constant Torque (CT) and the other is Variable Torque (VT). One thing you must remember is that both have different ratings. CT ratings are considered for general machine and conveyors while VT ratings are specific to pumps and fans. So, knowing these basic details will help you pick the right one.

You must pick a variable frequency drive that can match the full load current requirement of the motor, which you can check and identify on the motor nameplate. Also, you should know that VFDs create 3-phase power output, even when it is powered with single phase source. So your AC motor should be 3-phase.

Depending on the industrial application and power, the AC motor can experience extra loading during startup, which the drive must be able to handle conveniently. Also, apart from startup time, there are temporary conditions due to which there can be overload which the drive must handle. For extended overload periods over 60 seconds it is better to be equipped with oversized AC motor.

The drives come with a temperature rating and can withstand up to that much temperature generated in the enclosure. If the AC drive generated heat is higher than that, then there must be proper enclosure ventilation and cooling processes.

Most VFDs are designed and rated to operate at altitudes of up to 1000m. Therefore, if you are using the drive at higher altitude than that there could be decrease in cooling process because of denser air. This can be compensated by choosing an oversized drive.

Drives come with standard default carrier frequency. But you must also be able to alter the carrier frequency when there is a change needed in power consumption and heat dissipation.

Along with horsepower, you must also consider these important factors to pick the right and most suitable variable frequency drive for your particular industrial application.