ALTERNATING-CURRENT WINDING 211 



Fig. 245 illustrates a wound stator for an induction motor, 

 the winding of which has twelve coils laid up in two ranges, exactly 

 similar to Fig. 240. As is the case with the winding of Fig. 240, 

 the winding of Fig. 245 can be arranged as a two-phase six-pole 

 winding or a three-phase eight-pole winding ; the properties of each 

 of these windings being exactly the same as is set forth in 

 Table XVI. 



It will be seen from Fig. 245 that one coil is spread over 

 five slots on one side, i.e. it is a quintuple coil, whereas in Fig. 240 

 this spread was three slots, i.e. a triple coil. Also, there are three 

 conductors in each slot, and thus the number of turns in each coil 

 is 5x3 = 15. As has been stated above, it is too tedious to draw 

 out a winding diagram showing each individual conductor, and 

 such a diagram would be unnecessarily complicated. It is suffi- 

 cient to adhere to the rule of regarding each single radial line in 

 the winding diagram as representing the contents of a single slot 

 in this case, three conductors. 



The winding diagram would be exactly the same as Figs. 243 

 or 244, according as it is two-phase or three-phase, except that the 

 coils shown in these figures should be replaced by coils similar to 

 that of Fig. 246. The actual coil of fifteen turns would be as 

 shown in Fig. 246. 



For ordinary purposes in the winding shop it is not necessary 

 to provide the winder with a complete diagram of the whole 

 winding ; but so long as he has a diagram of the coil element and 

 also a diagram showing the connections between the coils, these 

 are sufficient to carry out the winding form. Thus Fig. 246 

 defines the coil element, and, working to this, the first coil would 

 be wound from slots 1 to 20, 2 to 19, 3 to 18, 4 to 17, 5 to 16, 

 covering five slots on each side. Slots 6 to 10 and 11 to 15 are left 

 for the front range of coils. So long as the first coil is wound 

 correctly, with the required number of conductors in each slot, 

 the remaining coils cannot help but come in their correct positions 

 when they are wound progressively round the armature. 



For connecting up the coils, a diagram in which each of them 

 is shown as a single thick line is sufficient, and this also serves fco 

 make certain the location of each coil. Such a diagram as that 

 given in fig. 247 would be sufficient, and in this diagram each 

 radial line would actually represent fifteen conductors distributed 

 over five slots, that is, one side of a quintuple coil. 



We have adhered to our convention of representing the back 

 range by dotted lines and the front range by full lines, and we 



