Blog Tag: variable speed motor

A very large number of appliances and motorized equipment that we use utilize electric motors. Some are very tiny and they run small appliances and consumer products like 3D Printers and grinders. Most of these are induction type motors that may have some form of speed controller or are just on/off motors. And, many of them are designed for single voltage use, meaning they are either 120 volt 60 Hz or 240 volt 50 Hz ( like those in Europe ). 

In 1998 General Electric developed a new motor that incorporated a magnetic drive system as opposed to a copper wound motor. These new motors could run forwards or backwards and would operate on 120/240 Volt 50/60 Hz current. First, this allowed them to be used any country in the world and secondly opened the door for development of a wide variety of new devices for many equipment manufacturers. 

In addition to being able to run in both directions, they could be controlled to run at increments of 1% to 100% in 1% increments making them extremely viable for applications where finite speed control was required. In addition, these motors can now be programmed to speed up or slow down based upon the performance requirements of the equipment. For example, if the motors are being used on systems that require different speed profiles for various performance requirements. These new motors can now also be operated by using a App on your phone so they can be controlled from any distance as long as there is wifi available. 

Pure Air Systems, an Indiana based corporation, has been using these new motors in their HEPA based, fan powered air filtration systems since 1999. PAS was one of the first companies to incorporate these motors into their systems replacing the standard induction motors. The new motors provided an entry into the European market and created an entirely new market for these air filtration systems. They could now be used both attached to existing HVAC systems with the ability to match the airflow requirements and also as stand-alone units where air filtration was needed in non-conditioned space.

For more information on our product line please go to our website at: http://www.pureairsystems.com   

In 1985 when Pure Air Systems was formed, the air filtration industry was using standard induction ( copper wound ) AC motors to run the fans that moved the air across the various types of filter media. Most often these fan powered units used HEPA filters as their primary filtration media.  Since HEPA filters have a fair amount of resistance due to their very dense media design,  motors in the range of 1/3 HP to 3/4 HP and larger were used for these applications. For the most part, these motors were all single speed, 120 volt, 60Hz  AC motors. Using any type of speed reduction controller with induction motors was difficult as the reduction in voltage to reduce speed also increased the heat load on the motor and created a hum or whine sound when dialing down the speed. As a result, most of the systems ran at one speed and one voltage.

In the late 90’s General Electric introduced a variable speed motor referred to as an “electrically commutated motor,” or ECM for short. This motor operates on using magnets rather than copper winding’s and can run forward or backward at any speed from 1% to 100% in 1% increments when controlled with a digital controller. Further more, it was designed to operate at 120/240 volt, 50/60Hz so it could be  used anywhere in the world. This new motor technology provided for variable speed control for filtration systems.

When using the standard induction motors the fan ran at one speed, which was high. This made a fair amount of noise and made it difficult to use it in areas that were occupied or where individuals were sleeping, reading or watching TV. The addition of the ECM motors allowed for use of even larger HEPA based air filtration systems to be used anywhere as the speed of the blower can be reduced so that the sound levels from the fan noise are low enough not to disturb people where the system is being used. Even at low speeds, the filtration efficiency’s are very good so moving air slowly over a long period of time is as effective as moving it at high speeds for short periods of time.

Pure Air Systems has over 6 models of HEPA systems designed to provide filtered air in any environment with a high degree of control. These units can be attached to existing ducted  HVAC systems or as stand-alone units. For more information on the complete line of  HEPA and Carbon based air filtration systems please go to our website at: https://www.pureairsystems.com or contact us on our toll-free number: 800-869-8025.