Kaeser Introduces New VFD Models with Improved Efficiency

Kaeser Compressors redesigns its Sigma Frequency Control (SFC) 45, 55, 75S, 90S and 110S compressors with advanced SynRM motor-drive combinations. These 60-125 horsepower units offer better part-load efficiency, longer service life and reduced maintenance costs.

Developed in partnership with Siemens and specifically designed to work with Kaeser's SFC models, the SynRM motor-drive combination achieves top-tier IES2 classification, resulting in better specific performance, especially in the part-load conditions that call for variable-speed compressors. 

The compressors do not use aluminum, copper or expensive rare-earth metals in the rotors. Instead, they are made of electrical steel and feature a special profile. With their unique rotor design, the motors run cooler — resulting in lower bearing and winding temperatures and increased motor life. And because there are no magnets in the rotor, motor service is safer and easier.  

To further enhance overall sustainability, SFC T models with the optional integrated refrigerated dryers have been upgraded with R-513A, a non-flammable, non-toxic advanced formulation refrigerant. R-513A has 56% lower global-warming potential (GWP) compared to the current US standard (R-134A). This, combined with Kaeser's advanced heat-exchanger design, reduces refrigerant requirements without compromising dryer performance. 

For more information, visit us.kaeser.com/SFC or call (877) 417-3527 to be connected with your local authorized Kaeser representative.