AC Variable Frequency Drives (VFD)

AC Drives, also referred to as AC inverters, Variable Speed Drives or Variable Frequency Drives (VFDs), are solid-state devices that are used to control the speed of 3-phase AC motors. Our VFD selection includes high-quality products from FMX, TECO, and WEG. Dynamic Braking Resistors, Dynamic Braking Units, and Line Reactors for both input and output are also available alongside these Variable Frequency Drives. Combined with excellent service and competitive pricing, this allows us to deliver the highest value to our customers.

FMX Tough Drive Series
TD200 Sub-micro VFD Drive

120V 1 phase input up to 1HP / 4.3 FLA
240V 1 phase input up to 3HP / 10.5 FLA
240V 3 phase input up to 3HP / 10.5 FLA
480V 3 phase input up to 3HP / 5.2 FLA

TD400

240V 1 OR 3 phase input up to 3HP / 10.5 FLA
240V 3 phase input up to 40HP / 138 FLA
480V 3 phase input up to 75HP / 145 FLA

TECO E510 - Type 4X

240V 1 or 3 phase input up to 3HP / 10.5 FLA
240V 3 phase input up to 20HP / 64 FLA
480V 3 phase input up to 25HP / 40 FLA

WEG CFW Series

120V 1 phase input up to 1.5HP / 6 FLA
240V 1 phase input up to 3HP / 10 FLA
240V 3 phase input up to 20HP / 56 FLA
480V 3 phase input up to 40HP / 49 FLA
575V 3 phase input up to 10HP / 12 FLA

Available Accessories

Braking Resistors
Braking Units
Line Reactors

What is a Variable Frequency Drive?
Variable Frequency Drives, also referred to as AC Drives, AC inverters, Variable Voltage Drives, or Variable Speed Drives (VSD), are solid-state devices that are used to control the speed of 3-phase AC motors. Their most common application is the control of 3-phase AC induction motors. An AC induction motor’s speed is dependent upon the motor’s physical construction. Specifically, the number of electromagnetic poles distributed in the motor’s stator and the frequency of the AC voltage applied to the motor determine its speed.

A VFD provides a variable frequency voltage waveform to an AC induction motor. Since the motor’s speed is dependent on the frequency of its AC voltage, the drive provides control over motor speed by changing both the voltage and the frequency of the motor’s AC waveform.

Where are VFD Drives Used?
VFDs are used with a large variety of machines due to their ability to reduce system stress on and increase control of motors that otherwise have a fixed speed.

Examples include:

Extruders
Conveyor Belts
Roller Tables
Fans / Exhausters
Centrifugal Pumps
Granulators / Palletizers
Dryers and Rotary Ovens
Process Dosing Pumps
Stirrers / Mixers
Rotary Filters
Winding Machines / Uncoiling Machines

Who Uses AC Drives?
VFDs are used in many industries such as:

Industrial Control
Material Handling
Oil and Gas
Food and Beverage
Mining
Power Generation
Heating and Air
Cement

Selecting a Variable Frequency Drive
It is imperative to know some information about your motor to select the proper AC Drive application. Here are some important factors to determine before making your selection:

Is Your Motor Suitable?

Most AC Drives are designed for 3-phase AC induction motors. Your motor must be a 3-phase, inverter-rated motor. Using a motor that is not inverter-rated can result in motor failure. Inverter-rated means that the motor’s insulation system is adequate for use with an AC Drive.

NOTE: In addition to induction motors, the FMX TD400 is designed to work with some permanent magnet motors.

What is Your Motor Voltage?

Know what voltage your motor requires to operate properly. The output voltage will vary and should match the requirements of your motor. Three AC Drive voltage classes are available to match the following motor voltage classes:

200V Class
400V Class
600V Class

Do You Know Your Full Load Amps?

The Full Load Amps (FLA) rating of the AC Drive must meet or exceed the FLA of the motor. To properly determine your needs, you must size the drive based on Amps:

Identify the Full Load Amps (FLA)* of the motor
Select the AC Drive that meets or exceeds this FLA rating

Full Load Amps (FLA) refers to the current of the motor at its rated load and voltage. It is equal to the amps the motor draws while producing the rated output horsepower. For more information on determining your FLA, view the [Determining Motor FLA app note]

What Voltage Will Be Applied to the AC Drive?

When sizing your AC Drive, you must know the voltage of your power source. Here are the available power options:

NOTE: Remember that although certain Variable Speed Drive models may accept single phase input, they will always provide three-phase output to the motor.

What Environment Will Your Drive Be Installed In?
Ideally, AC Drives will operate in a cooled and clean environment. Failing to keep the AC Drive properly cooled, cleaned, and ventilated can result in failure of the device. We offer three main chassis types with different environmental ratings:

IP20 – Indoor finger-safe protection against solids over 12.5mm, or about half an inch. No protection against liquids.
NEMA 1 – Indoor use primarily to provide protection against contact with the enclosed equipment and against a limited amount of falling dirt.
NEMA 4 – Protection against dust, dirt, and similar small debris and a degree of protection against liquids. Able to be installed outdoors when protected from direct sunlight.

On all AC Drive chassis types, it is critical that the heat sink and fans are kept clean.

Other Considerations
There may be other factors to consider depending on your application when sizing your AC Drive.

Does your application require derating of the AC Drive?
Is your application outside of normal use for the AC Drive?

De-rating
AC Drives may require de-rating to accommodate for:

Using a 3-phase input drive with single phase input
Rapid acceleration/deceleration
Excessive rate of starts and stops
High altitudes
Ambient temperatures (including temperature inside enclosure) exceeding 40°C
Loads that require higher-than-normal starting torques

[Click here for an example on how to de-rate three phase input AC Drives for single phase input using the FMX TD400]

Special Considerations
Some applications operate beyond the normal considerations of AC Motor and/or AC Drive design. These applications can include (but are not limited to) applications with excessive start/stop cycles and fast cycle times, higher than normal starting torque, overhauling, highly regenerative loads, DC motor replacement applications, solar applications, and irregular voltage and/or speed patterns. If your application features these or other special considerations, please contact our technical support staff to ensure that you are choosing the right AC Drive for the job.

FMX
When you see the FMX brand on a product it means you can be assured of high quality and competitive pricing. Most FMX products are produced in the same factories and on the same production lines as many well-known major name brands offered in the market today. All of these products meet or exceed the expected quality and certification requirements in the United States for many industrial applications and undergo stringent testing to ensure they will perform according to standards in the field.

FMX Products Include:

Variable Speed Drives
Miniature Circuit Breakers
Motor Controls
Panel Meters
Relays
Sensors
Signal Lights
Terminal Blocks
Wiring Solutions

More about FMX

TECO
Since their inception in 1956, TECO Electric & Machinery Co., Ltd. has evolved into a major manufacturer with products spanning many industries including the industrial control industry. TECO produces drives compliant with various kinds of stress, position, speed, turning moment, and load for all-round applications.

TECO Products Include:

Variable Speed Drives
Braking Options

More about TECO

WEG
WEG is one of the largest industrial electric control manufacturers, producing more than 21 million units annually and always striving to improve. Attention to detail is the hallmark characteristic at WEG. All products, including their line of AC Drives, are driven by the desire to increase efficiency. WEG manufactures reliable AC Drives with varying module attachments. Depending on the project environment and application, WEG provides a wide variety of product types, sizes, and technology.

WEG Products Include:

Variable Speed Drives
AC Motors
Pushbuttons
Soft Starters

More about WEG