ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. 131 
stance, to investigate if the iron and copper sources are 
properly divided. 
218. Normal Magnetic Flux.—<According to Pars. 182 to 
187%, a machine of a certain capacity per revolution should 
have a certain amount of normal magnetic flux, to make 
it a suecessful commercial design. 
>” 
4 
K ' 
In the present case a 0.8, the normal output being 
400 KVA. and the number of revolutions 500. From Fig. 
62, the value of the total fiux for the normal open cireuit 
voltage should be about 55 X 10° magnetic lines; that is, 
5 xX 10° 
the fiux per pole should be about F, = ee = 4.6 x 10° 
lines; while from Equation (33) : 3 
2.3 x 50 x 24x 18 x F, 
10° 3 
2,040 = 
~ which gives 
F? = 4.12 X 10° lines per pole. 
In the above equation 2,040 is the phase E.M.F. in volts; 
2.3 is the value of the form factor corresponding to the 
two slot winding and to the pole are ratio of 0.61, see 
Table 14; and 24 x 18 gives the number of the armature 
conductors per phase. 
219. Actual Flux Value.—tThe actual flux value of 4.12 x 10° 
lines is about 10% smaller than that indicated by Fig. 62; 
consequently it is ceneluded that the number of armature 
conductors has been chosen somewhat higher than usual 
and that the value of the regulation can only be obtained 
by the application of more field ampere turns than is 
usually found in a standard design. 
220. Choice of Lower Flux.—The choice of the somewhat 
lower flux permits the reduction of the iron, but on the 
other hand requires an increase of copper. As will be 
