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Permanent Magnet Variable Frequency Motor For Air Compressor


With the motive to reduce the Energy cost in our air compressors, we now introduce Energy-saving Permanent Magnet Motors with our VFD models which decreases Energy consumption substantially to save even more energy as well as money.

Enneng permanent magnet motor uses a motor with a temperature rise lower than 60K, ensuring the compressor has a longer life. The motor is made from rare earth permanent magnet material, which requires a low current due to its high magnetic strength and load torque during motor start-up and operation. The combined use of this motor and permanent magnet rotor achieves soft-start and electricity saving of up to 50%, with the motor's efficiency up to 10%-15% when compared with an asynchronous motor with the same specifications, thus avoiding a powerful mechanical impact on the compressor under the motor's full pressure start and ensuring a longer service life.


Variable speed motors in air compressors, because of the high efficiency at wide speed range, brushless DC motors are widely used at variable speed conditions.

This motor is used in an air compressor system, compared to an asynchronous induction motor system. Thanks to its advantages listed below, which is to be used that have variable requirements provides up to 35% energy saving and improves the compressor’s service life.

1.  High efficiency at variable speed

At a constant speed that both asynchronous motor and permanent magnet DC motors can work at high efficiency. But using an asynchronous motor, when the motor speed is changed, the motor efficiency goes down sharply, but using the permanent magnet DC, at a wide speed range, the motor efficiency keeps at high efficiency.

2. Soft Start and Longevity

The excessive current drawn during the star-delta of the electrical motor (starting current) and the mechanic loads are eliminated thanks to the soft start and stop features of this system. As a result, the longevity of the motor equipment improves and maintenance costs decrease.

3. Economical Run and Constant Output Pressure

Standard air compressors switch to idle when the targeted pressure is achieved and switch to load when the specific low pressure is reached. When the compressor switches to idle, the electrical motor keeps working at its constant speed and does not produce compressed air hence the compressor consumes 30% power of its load run. Pumps with our permanent magnet motor work at an optimum speed (rpm) to meet the real-time air needs and provide a great deal of energy savings as well as produce targeted constant output pressure.

In some cases, because we can’t rule out the possibility of long-run in full load condition, we have to order motors to meet the maximum demands of compressors. But in actual operation, the proportion of light load running time is quite high, which leads to a lot of energy waste. From now on, with our permanent magnet motor system, you can order a motor at rated power, and peak power can meet the full load condition. By the close loop control, the motor speed is variable automatically by your pressure condition. Moreover, we can produce customized motors for our various applications.

For professional compressor case advice, please contact us at sales@enpmsm.com. Our engineers are at your service case by case. You can try to tell us your compressor application, function requirements, efficiency, etc. our permanent magnet motor pumps systems can easily replace the conventional 3 phase asynchronous electric motors with higher efficiency and intelligence.

air compressor motor