A growers guide to VFD terminology

A Grower’s Guide to VFD Terminology


Understanding VFD terminology helps users to ensure proper application in the field. This article and the attached PDF file details 50 of the most important VFD terms that VFD users should understand to more effectively specify and maintain their drives.

What is a variable frequency drive and how are they used in agriculture?

VFDs are used to regulate the speed of motors by varying the alternating current (AC). The frequency converter also has the ability to control the ramp-up and ramp-down of the motor when starting or stopping. Across the Central Valley and Central Coast of California, VFDs are commonly used in agriculture to control motors that drive deep well turbine pumps and centrifugal pumps to move irrigation water.

Keeping up with all of the terminology surrounding the usage of variable frequency drives can be daunting. Maybe if there were one place where you can look up definitions of these ever-increasing terms it would make it easier to be a power user of variable frequency drives. With the help of excellent resources from Yaskawa, we aim to make you the alpha drive user you always wanted to be.

In the attached PDF file, you will find some real-world definitions of many of the confusing terms thrown around in VFD (variable frequency drive) manuals and technical articles. This PDF contains 50 of the most important VFD terms for today’s variable frequency drive users.

Key Takeaways

  • A VFD consists of 3 primary sections, the rectifier/converter, the DC bus and the inverter.
  • The number of poles in a motor is one of the factors used to determine the motor’s torque/hp and rpm/Hz.
  • Permanent magnet motors are more efficient and smaller than induction motors. However, not all VFDs can operate PM motors.
  • Open and closed loop control allow VFDs to realize the best characteristics of DC drive control without the maintenance and high initial cost of DC motors.
  • Every VFD needs to be configured as to where the command to start the motor will come from

Reference: The ABCs and 123s of Variable Frequency Drives, Date: 5/12/22, Document No. WP.AFD.34

Yaskawa is the leading global manufacturer of low and medium voltage variable frequency drives, servo systems, machine controllers and industrial robots. Yaskawa’s standard products, as well as tailor-made solutions, are well-known and have a high reputation for outstanding quality and reliability.

Local Support for Pump and VFD Needs

As a full-service irrigation company located in Kerman, Paso Robles, Hanford and Bakersfield, Cal-West Rain designs, installs and maintains turn-key irrigation systems for growers of all types and sizes. Our design team and pump department routinely specifies and supplies Yaskawa VFDs, along with other major brands based on the application and customer preference. To learn more, contact Cal-West Rain.

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