Internal connections in high-power LV motors are commonly so complex. Why? These windings are designed regularly with a number of parallel circuits, but, because of some reason, the coils are not connected in standard manner . Connections are quite strange and complex, and it is sometimes difficult to record it properly. Usually, technicians are trying to ease the job and do something simpler. Does the standard connection is good substitution for such a complex winding?
No. An example of winding diagram with double-layer concentric winding 72 slots, 4 poles, 4 circuits (24 groups instead of 12; 4 circuits are designed in a special way) is available here.