The ACS DriveIT low-voltage 800-17 four-quadrant motor drive is 80 percent smaller than alternative units, claims the company. They range from 75 to 1,250 horsepower (hp); custom units can be built in sizes up to 4,000 hp. A typical HVAC application for the drives is for chiller control for office buildings. According to the company, the drive eliminates harmonics through Direct Torque Control (DTCâ„¢), removing low-range frequencies up to 1 kHz, as well as handling medium and high frequencies. In the drive, the line voltage actively is switched, with the switching modulated to deliver a sinusoidal line current. The DTC also acts on the line current, compensating voltage variations, to maintain an even waveform.
ABB Inc., 16250 W. Glendale Dr., New Berlin, WI 53151; 800-752-0696; 262-785-8525 (fax); www.abb.com/us.