In-house motor design drives ultra energy-efficient compressor

Tests reveal efficiency savings over traditional fixed speed designs

Tests of a new type of compressor which features a patented interior permanent magnetic motor (IPM) have revealed 50% efficiency savings over traditional fixed speed designs, it has been claimed.

Atlas Copco said the breakthrough has been made possible as a result of the in-house development of the IPM motor, the first time it has manufactured such an item for its compressor range.

The vertically mounted, IP66, oil-cooled motor, was specifically designed to match its screw element. It is IE4 certified to the highest levels of motor efficiency, meaning that the GA 7-15 kW VSD+ out-performs comparable fixed speed compressors even at full load.

Atlas Copco said that 25 endurance units tested in the field over the course of the past three years showed that it offered energy savings of up to 50% compared to traditional fixed speed compressors. And the new design was shown to be 15% more efficient than Atlas Copco’s current variable speed drive compressor, while also providing a leap in free air delivery (FAD) of 12%.

Paul Clark, business line manager at Atlas Copco's industrial air division, said the performance of the new design would “convert engineering firms from fixed speed machines”, encouraging them to switch over to variable speed drive compressors.

Instead of the normal horizontal layout, the GA 7-15 VSD+ has a vertical layout that provides a canopy size 55% smaller than existing models. This 610 x 630mm footprint allows it to be placed on the production line, rather than an outside space. Since only two panels need to be removed for servicing, it can even be placed against a wall. As a result, plant managers are able to save floor and work space, as well as easing maintenance access and installation, said the firm.

The new compressor runs at 62 dB(A), thanks to the integration of an ERP 2015 compliant efficient fan motor that reduces electricity consumption and noise levels. The low noise levels are further aided thanks to the compressor having separate compartments for the drive train and cooling system. A full feature version comes with an integrated dryer.

The test results were confirmed by third party verification by independent testing laboratory Laborelec, which substantiated the claims for energy savings.