Variable Frequency Drives (VFD) in North and South Carolina

Save Energy and Money with Eaton VFD’s

Hahn Mason, Inc. offers a wide variety of motor controllers, in particular – motor starters and adjustable frequency drives. Applications for these types of equipment include variable torque loads, consisting of fans, pumps and blowers, as well as constant torque loads, which consist of conveyors, extruders and more. Motor starters are a great add-on to a motor when the application requires speed and torque control only during motor startup. Whereas adjustable frequency drives control the speed of the motor not only at startup or stopping, but throughout the run cycle. Owners will see more cost savings from energy efficiency on an adjustable frequency drive rather than a motor starter.

Why Work with Hahn Mason for Your VFD Application?

Hahn Mason, Inc. has personnel capable of properly sizing and selecting a specific motor controller based on your application and need. Beyond that, Hahn Mason also has personnel who are certified to start-up and commission Eaton drives throughout North Carolina and South Carolina. This enables us to provide these services in a timely manner for your project. Eaton does provide a standard 2-year warranty on all drives. However, for specific drives, such as HVAC applications, an authorized commissioner of the product who performs the start-up would extend that warranty to 3 years.

Why Choose Eaton for Your Variable Frequency Drives?

As a proud representative of Eaton’s adjustable frequency drives and motor starters, Eaton offers a best-in-class portfolio of drives to fit your application. They are designed for your performance requirements and will save you space, improve safety and work smarter in your building. Specifically to Eaton products, owners could gain up to an extra 10% more energy savings due to features such as Active Energy Control®, an algorithm that monitors the output power performance while reducing the input power requirement for variable torque loads. Other key components that make Eaton a leader in this technology include Sensorless Vector Control, which improves speed regulation, a built-in multi-pump and fan feature, allowing control of multiple pumps or fans from a single process signal without the need for a separate controller, and many more. Hahn Mason has many years of experience with motor controllers and will assist you in sizing and selecting the proper equipment and provide an optimal solution for your HVAC need.

VFD North Carolina

VFD South Carolina

Drives and Motor Starters Offered by Hahn Mason


Adjustable frequency drives are larger in size compared to the motor starter and is used to protect and control the speed of AC induction motors. The rectifier converts the initial facility power (typically 480V, 60Hz) from AC to DC power. From there, the filter and DC bus work together to smooth out the rectified power to provide clean, low ripple DC power to the inverter. The inverter is the last stage, which consists of IGBT’s (insulated-gate bipolar transistors) that act as switching mechanisms in varying widths on the inverter semiconductors, creating a similar sine waveform. This process with the IGBT’s is known as pulse width modulation (PWM), which is how the new AC power is created and sent to the motor as an adjustable frequency. A VFD is typically provided when the following requirements are specified:

  • Complete speed control is required
  • Energy savings is a goal in addition to reducing large startup inrush currents of motors
  • Custom control is needed
  • The project includes fans, blowers, and/or pumps.

Solid-State Motor Starters

A motor starter, also known as a soft starter, is a solid-state device that protects AC electric motors from damage caused by sudden influxes of power by limiting the large initial inrush of current associated with motor start-up. Motor starters reduce voltage or current by incorporating SCR’s (silicon-controlled rectifiers) which restrict or allow current based on it’s off and on state. A project may only need a solid-state drive when the following apply:

  • Speed and torque control are required only during startup (and stop if equipped with soft stop)
  • Reducing large startup inrush currents associated with a large motor is required
  • The mechanical system requires a gentle start to relieve torque spikes and tension associated with normal startup (for example, conveyors, belt-driven systems, gears, and so on)
  • Pumps are used to eliminate pressure surges caused in piping systems when fluid changes direction rapidly

What Do We Need to Know in Order to Generate Your VFD Proposal?

The most important information we would need to know is the following:

  1. Application (variable or constant torque)
  2. Voltage and Phase
  3. Full Load Amps (FLA)
  4. Horsepower
  5. Environmental factors which include:
    • Ambient Temperature
    • Altitude
    • Indoor/Outdoor application
    • Humidity
    • Air Quality
  6. What is the intent of the controls?

Tools You can Use for Your Project:

Contact Hahn-Mason for Your Next VFD Application

For more information on VFDs, contact Hahn-Mason Air Systems today at (704)-523-5000. We are proud to serve you from our 9 local offices and warehouse locations in Charlotte and Charleston.

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