Variable Frequency Drive Systems and Controls

  • Do you have ac motors in your facility?
  • Do these motors need a variable output?
  • Do you use mechanical means to vary the output?

If you answered yes to these questions, you need to install variable frequency drives on these ac motors.
If you are not using VFD’s you are wasting energy and throwing money out the window.

Two Door Cabinet with ABB's NEW ACS 800 AC DriveIn the United States 50% of the total electrical energy generated is consumed by rotating equipment. 65% of this total is consumed by centrifugal or flow related applications such as fans, blowers, compressors, and pumps according to current estimates. Variable speed drive technology offers a cost-effective method to match driver speed to load demands and represents a state-of-the-art opportunity to reduce operating costs and improve overall productivity.

Joliet Technologies is an OEM that engineers, integrates, and custom packages AC Variable Frequency Drives (VFD), DC Variable Speed Drives (VSD) and AC Drive Controllers. Our drive systems integrate top of the line manufacturers, like ABB, Yaskawa, Siemens, WEG, and Fuji, to name a few. Our value added custom drive packages are built to your specifications for your application.

What is a Variable Frequency Drive?

You can divide the world of electronic motor drives into two categories: AC and DC. A motor drive controls the speed, torque, direction and resulting horsepower of a motor. AC drives control AC induction motors. DC drives typically control shunt wound DC motors, which have separate armature and field circuits.

Motor drives are also known as DC Drives, AC Drives, SCR Drives (Silicon Controlled Rectifier Drive), Variable Frequency Drives, Variable Speed Drives, Adjustable Speed Drives, Electric Motor Drives, Electronic Motor Drives, AC Motor Controllers, AC Inverters, Pulse Width Modulation (PWM) Drives and a few other names.

Which Drive is Right for your Application?

The AC Variable Frequency Drive market is huge, due to the great advances in highly reliable AC power electronics and high power microprocessors. The Flux Vector AC Drive, for example, can now be used in many applications that once required the use of DC Drives.

Variable Speed DC Drive.Even though AC Variable Frequency Drives are readily replacing DC Drives and motors, there is still a large base of DC equipment that has to be supported by experienced technicians. Joliet Technologies is well positioned to support customers in the DC market. For example, older machines with multiple existing DC analog drives and motors may be a great candidate for retrofit to newer digital DC drive equipment, reducing life cycle costs and down time.

If speed control is not part of the work scope, Joliet Technologies can provide custom AC drive controllers consisting of contactors, starters, relays, pushbuttons and PLCs. Our engineers can provide all PLC and peripheral programming needs. Panels can be designed by another OEM or we can engineer to your specifications.

DC Variable Speed Drive
Torque control and limiting Brush life commutation maintenance
Wide speed range (under 5000 RPM) Motor high speed limit (high speeds use expensive gear boxes)
Trimming capabilities Expensive large HP motors
Constant HP capabilities Power system harmonics
True 4-quadrant regenerative energy conversion NA
Few distance limitations NA
Cost (especially single phase sizes) NA
AC Variable Frequency Drive
Improved efficiency Distance limitations
Low motor maintenance Large system designs (high HP drive foot prints)
Tight control Cost (encoder feedback)
Digital control Expensive regenerative braking
High speed capabilities Power system harmonics
Reversing capability without extra power elements NA

Variable Speed Drive.Joliet Technologies Custom Panel Shop and On-Site Retrofit Benefits

We have the experience and know how to provide you with the best drive for your application. Joliet Technologies can evaluate your current equipment and recommend either a Retro-Fit or System Replacement. Feel free to contact us with any drive questions you may have.

"Underwriters Laboratories Inc. (UL) is an independent,<br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /> not-for-profit product safety testing and certification organization.<br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /> UL has tested products for public safety for over a century.<br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /> Each year more than 17 billion UL Marks are applied to products worldwide."<br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /> "UL is not affiliated with Joliet Technologies and does not endorse the Web site."Joliet Technologies is a UL (Underwriters Laboratories) 508A Certified, Industrial Control Panels & Industrial Control Panels Certified for Canada shop.

Joliet Technologies is dedicated to provide the highest quality equipment and service. Our experience, expertise and commitment ensures you will be completely satisfied with our products and services. All work is performed following our Quality Assurance System (based on the ISO9001:2008 Standard), assuring you the highest quality.

From system integration to panel fabrication Joliet Technologies provides quality systems and custom control panels for new applications or system upgrades, all in a timely fashion, and at competitive rates.

How to Maintain a VFD

Do you know how to maintain a VFD? Doing so is easier than you might think. By integrating some simple, logical steps into your preventative maintenance program, you can ensure your drives provide many years of trouble-free service.

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Request for Quote

  • Fill out this simple, No Obligation form (should only take a few minutes), and Joliet Technologies will send you a detailed quote.
  • Or, if you have existing documentation of your specifications and application, simply attach them to an e-mail to, and Joliet Technologies will send you a detailed quote.
  • Or, send us an e-mail detailing your specifications and application to, and Joliet Technologies will send you a detailed quote.
  • We will not use your contact information for any other purpose than to communicate with you about your request.

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