QT Series   (Variable Speed Control)       The QT Series provides variable speed controI via frequency inverters and a specially developed control system operating with a pressure transducer. The system is designed to maintain a predetermined set pressure against varying demand by regulating the speed and number of pumps operating automatically. The set features power on and enabled L.E.D's with L.C.D display providing many display options and full programming capability. The units are available in one, two and three pump versions up to 2.2kW single phase and 55kW three phase.