Nidec SynRA™ Synchronous Motor is an innovative, patent-pending, synchronous motor. The motor offers one of the highest efficiencies available for today’s HVAC and commercial pumping equipment – with ratings at IE4 and IE5. Our judges recognized this intuitiveness by naming the SynRA the 2022 Commercial Comfort Product of the Year in the Motors & Drives category.        

The plug-and-play installation can connect to building automation and meets commercial building owners’ requirements for energy savings — offering a low lifetime cost of operation. This new technology from Nidec’s U.S. MOTORS® brand also allows commercial HVAC contractors or building maintenance staff to easily replace a motor without having to install an entirely new system and controls, saving time and money.  

“SynRA provides the operating benefit of a pure synchronous reluctance motor and suitability benefit from a simple volts/hz drive,” said Chris Couch, market manager, Nidec. “The unique design gives the freedom to replace components individually instead of the entire system, leading to a lower cost of maintenance. The product’s smart building technology results in less wear and tear on blower or pump systems by matching application demands with variable speed.”

SynRA features an aluminum cage, a unique design characteristic in the synchronous motors sector. This feature allows the motor to start like an asynchronous induction motor and transition to synchronous operation. Benefits include no RPM slip, higher peak efficiency, and a flat efficiency curve.

“Both induction and synchronous motors utilize the exact same stator laminations and windings,” said Couch. “The only difference in the two technologies is the rotor construction. A squirrel cage induction motor generates torque through an induced current, resulting from rotor slip, meaning the motor RPM is slightly slower than the stators rotating magnetic field. This induced current generates heat and rotor losses but also allows the motor to run direct-on-line or on a V/Hz drive. An added benefit of utilizing a V/Hz drive is multiple motors are able to run on a single drive, since the drive doesn’t need to know the rotor position to operate thus, simplifying installations.”

The unit’s magnet-free design allows for easy programming and compatibility with existing variable frequency drives (VFDs). A model fully integrated with Nidec’s ID300 PerfectSpeedTM is currently available. When paired with a V/Hz VFD, the SynRA motor achieves the industry-leading efficiencies of IE4 and IE5.  

Research and development on the SynRA was conducted in coordination with Nidec research centers in Taiwan and France. The primary tools included Electrical and Thermal FEA as well as internal electrical analysis tools. That was followed by sample creation in Asia and North America.  

“Testing and evaluation occurred in five different labs around the world (France, Taiwan, Mexico, St. Louis, Chicago) to test different aspects of the design and to do performance verification and correlation to design estimates,” said Couch. “Discussions on design also occurred with contracted university professors throughout the primary design process as well as testing confirmation.”

The 1-10 hp IE4 units are rated at 1,800 RPM, and the 1-15 hp IE5 units are rated at 3,600 RPM.

The units are applicable to numerous applications. The inverter driven VT loads are suitable for pumps, fans, and blowers for HVAC and other systems. Other applications include OEM constant pressure booster pump systems, OEM variable speed hydronic pump systems, and super premium replacement VFD motors.

 The Verdict Is In

The judges selected the SynRA, citing its all-around effectiveness, usefulness, and a list of other benefits.

“The SynRA was my top choice due to its high energy efficiency, ease of retrofit, and compatibility with existing building automation systems and VFDs,” said one judge. “The backwards compatibility and retrofit advantages allow for simple addition of enhanced controllability in both retrofit and new build applications.”

“I appreciate the Nidec unit’s ability to run direct-on-line with a drive and run multiple motors on one drive,” said another judge. “Combined with the plug-and-play control’s integration with the BAS, this provides building owners versatility and flexibility.”