by Brianna Crandall — June 15, 2016 — NovaTorque, a Fremont, California-based producer of electronically commutated permanent magnet (ECPM) electric motors, has introduced 900 RPM versions of its 1.5, 2, 3, and 5 horsepower (hp) models. The new models are said to provide a full load motor-only efficiency rating of 92 to 94 percent compared to about 82 to 87 percent for conventional AC induction motor ratings.
Additionally, NovaTorque motors maintain high efficiency under partial load (AC induction motors do not), making them ideal for variable speed fan applications. The efficiency advantage of a 900 rpm NovaTorque motor versus an 8-pole 900 rpm AC induction motors can grow to 20 points or more at half-rated speed in such applications, which is a 67 percent reduction in motor losses (wasted energy), says the company.
“There are many continuous-duty applications where required fan speed is in the 300 to 500 RPM range. For example, data center cooling applications — where high-flow and low-static pressure is desired — require a large-diameter fan running at a relatively low RPM,” said Scott Johnson, vice president sales, NovaTorque.
“To date, however, low-speed direct drive applications haven’t been practical due to the high cost and low efficiency of 900 RPM 8-pole induction motors,” continued Johnson. “NovaTorque’s 900 RPM ECPM motors change that paradigm with the combination of ultra-high-efficiency across a broad operating range at prices substantially lower than those of 8-pole induction motors.”
NovaTorque 1.5HP PremiumPlus+ electronically commutated permanent magnet (ECPM) motors for variable speed applications are now available in 600 RPM, 900 RPM and 1200 RPM versions.
An additional benefit of NovaTorque’s unique flux focusing stator and rotator technology is the ability to often be one full frame size smaller than conventional induction motors, providing substantial weight and space savings, says the company.
“The 182T/184T size in the 3 Hp 900 RPM motor provides a weight savings of 70 pounds over a conventional induction motor with the same output power and speed,” Johnson said. “The 5 Hp 900 RPM motor provides a weight savings of 100 pounds or more over a comparable conventional induction motor.”
The NovaTorque motor achieves this efficiency gain, and smaller size with an all-ferrite (versus rare earth) magnet design, which provides a substantial cost benefit over conventional permanent magnet motors using costly rare earth materials.
“The combination of higher efficiency and smaller size provides substantial benefits to OEMs and HVAC systems designers who are using low-speed fans to reduce noise due to air cavitation, and other designers seeking cost-effective electric motor solutions,” noted Joe Weber, senior director for product management and marketing, NovaTorque.
NovaTorque motors are packaged in standard NEMA frame sizes and mounting dimensions for easy substitution of AC induction motors. They are said to be compatible with readily available variable frequency drives (VFDs) from most leading manufacturers, including ABB, Yaskawa, Mitsubishi, Siemens, Fuji, Hitachi, Toshiba, Delta, Danfoss, Schneider, Vacon, and others.
