Specifications

To draw the main winding diagram, solid lines of equal length and equal distance equal to

number of slots is drawn. Connect the coils as per the Winding Table 4.1.

Arbitrarily assume a particular current direction to the coil sides under the pole pairs. For

the coil sides under North Pole regions, assume downward current direction and vice versa for

the South Pole regions, as shown in Fig. 4.1.

Fig.4.1 - Single Phase AC Lap Main Winding Diagram

AC Wave Winding : Develop a single phase, single layer wave winding for a 4 pole, 24 slot ac

machine.

Solution : Number of coils, C = 12

From equation 3.5, the pole pitch = = 6; and slots per pole per

phase, m = = 6

Slots 1 to 6 and 13 to 18 lie under North pole regions N1 and N2 respectively. Similarly slots

7 to 12 and 19 to 24 lie under South pole regions S1 and S2 respectively. In other words, the

first pole pair covers slots 1 to 12 and the second pole pair covers slots from 13 to 24.

For full pitch winding, angle between the two sides of the same coil is 180

. 180

corresponds to 6 slots.

For ac wave winding, back pitch, Y

= number of coils(or slots) per pole= 6 = front pitch, Y

If one side of the coil is placed in slot no. 1, the other side of the coil should be placed in slot

no. (1 + slots per pole = 1 + 6 =) 7. The finishing end of the coil side at slot no. 7 is connected

to the starting end of the coil side at slot no. (7 + 6 =) 13. Now the other side of the coil side at

slot no. 13 is placed at slot no. (13 + 6 =) 19. Adding 6 to slot no. 19 gives 25, which is slot no.

1, ie., 25 – 24 = 1. But a coil side is already placed at slot no. 1. So add 1 and place the coil side

at slot no. 2. Similarly, add turn by turn back pitch and front pitch and at the end of each round

add Y

+ 1. Table 4.2 gives the complete winding table for a 4 pole 24 slot ac wave wound

machine.

12345678910111213141516

19 20

21 22 23 24

N1 S1 S2N2

Number of slots

Number of Poles