ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. 129 
p = 6; and the pole pitch is equal to: 
171.44 
12 
= 14.28 inches. 
214. Pole Are Ratio.—tThe length of the pole are is indicated 
in Fig. 66 as 8.75 inches; therefore the pole are ratio is 
found to be: 
B70 
14.28 
which is a standard value. 
The two edges of the pole shoes are well rounded off so that 
the magnetic lines will be less dense on this part than in 
0.61, 
Fie. 68.—PoLE WINDING, 400 KVA., 3,500 VoLts 3-PHASE 
ALTERNATOR. 
the middie of the pole shoe, as such a condition favors the 
sinusoidal wave form. 
215. Winding Details.—The pitch on the external diameter 
of the wheel rim is equal to 
40.1 X 3.14 
12 
where 40.1 inches is the diameter given in Fig. 66. 
The width of the pole core being 6 inches, the smallest 
= 10.46 inches 
