Repair of a split-phase motor with a damaged winding consists of several operations: taking the winding data, stripping the old windings, insulating the slots, winding the coils and placing them in the slots, connecting the windings, testing, varnishing and baking the winding.
Before the motor is taken apart, the end plates should be marked with a center punch so that they may be reassembled properly. One punch mark should be put on the front end plate and a corresponding mark made on the frame. Two marks should be made on the opposite end plate and also on the frame at that point.
Taking the winding data is one of the most important parts of the operation This action consists of obtaining and recording information concerning the old winding; namely, the number of poles, the pitch of the coil (the number of slots that each coil spans), (fig. 7-31), the number of turns in each coil, the size of the wire in each winding, the type of connection (series or parallel), the type of winding, and slot insulation. See figure 7-32.
This data is taken while removing the old winding from the motor frame. One coil should be cut at a place where the number of turns may be counted. The size of the wire and other data is then entered on the data sheet.
Figure 7-32. - Split-phase motor data sheet.Continue Reading