Dynamoelectric machine winding arrangements, dynamoelectric machines incorporating same and methods of operating such dynamoelectric machines

摘要

A motor particularly designed and adapted for starting as a high resistance auxiliary winding, low "a" ratio resistance split phase motor and for operating continuously thereafter as low resistance auxiliary winding, high "a" ratio capacitor motor. The motor has a primary winding phase with a number of effective winding turns n.sub.le ; a first auxiliary winding section with a number of effective winding turns n.sub. lesr for having a first positive magnetic effect; and a second section of an auxiliary winding phase having a number of effective winding turns for having a negative magnetic effect; and wherein the first and second sections, when energized at the same time, have a second preselected number of effective winding turns n.sub.less which is less than n.sub. lesr. The ratio of n.sub.less to n.sub.le (defined as "a.sub. s ") is in a first range; and the ratio of n.sub.lesr to n.sub.le (defined as "a.sub.r ") is in a second range. These ranges are chosen to provide good capacitor motor running performance; and to provide good starting and accelerating performance as a resistance split phase motor. During starting conditions, the main winding current is influenced by the ratio "a.sub.s " and its current characteristic causes proper relay operation. The relay opens its contacts at a main winding current condition corresponding to a chosen motor speed. The auxiliary winding is interrelated with the relay contacts so that, during starting conditions, two auxiliary winding sections are energized; but only a first auxiliary winding section is energized after the relay contacts open. In preferred applications, both sections of the auxiliary winding phase are energized during starting conditions and the total auxiliary winding phase presents a relatively high resistance load to the power source while the second section of the auxiliary winding phase shunts a capacitor. When the second section of the auxiliary winding phase is de-energized, the relatively lower resistance first section of the auxiliary winding phase continues to be energized--but through the capacitor. In this mode, efficient running performance usually associated with capacitor motors is attained. The first and second sections of the auxiliary winding phase may be made of the same winding material and may be of the same size (i.e. , diameter). Alternatively, higher resistance per turn materials--for example, such as smaller diameter copper, or other materials may be used for the second winding section.