• National Electrical Industry

AC Synchronous Motors, 5.5-11 kW

National Electrical Industry (International Marketing Division) offers AC Synchronous Motors in 5.5-11 kW ratings. With global research going on to bring efficiencies to optimum, the PMSM called AC synchronous motor works on same principal of reduction of speed and increase of torque. It works on same principal of speed/torque relation because the gearbox is no magic box to give lower speed and high torque but works on principle of 2?NT = Watts, i.e., 2? are fixed values. Therefore if `N’ (speed is lowered by gearing then `T’ torque goes up and Watts, i.e., motor fitted with gearbox is again constant value. Same principal applies in PMSM technology, i.e., increase of poles of AC motor and thereby decrease of speed result in torque going up. Mechanical transmission, planetary gearbox, helical gearbox or worm gearboxes consume 10-40% energy transmitted through it. These motors eliminate all these transmission losses. High performance PMSMs (AC synchronous motors) are available in 18 poles and 24 poles to give 92% efficiency and 0.98 PF in 3 rating at present. Further one can operate these motors, which have constant torque, efficiency and PF from 2 Hz to 50 Hz, i.e., at any speed. Note: In Europe, one will not find any elevator with gearbox and same principal is also applied in all industrial usage and applications.