18 
ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. 
‘DESIGN A REVOLVING FIELD TYPE SINGLE PHASE ALTERNATOR TO THE 
162. 
163. 
164. 
165. 
1 66. 
167. 
THE FOLLOWING SPECIFICATIONS BY ANSWERING 
QUESTIONS 162 To 206. 
Output = 75 KVA. 
Speed = 600 revs. 
Frequency = 60 cycles. 
Terminal pressure = 1,000 volts, 
Load-power, factor, cos Pp = .95. 
The efficiency must not be below 89% at full inductive load. 
The voltage drop shall not exceed 12% at full inductive 
load. 
The temperature rise on any part of the machine shail not 
exceed 75 degrees Fahrenheit. 
For the armature winding the long coil type in open slots 
is to be applied and the armature core is to be made up 
of .02 inch lamine. 
For the poles .04 inch lied are to be applied. 
Determine the necessary number of poles. 
Caleulate the horsepower of the steam engine to which this - 
alternator has to be coupled. 
By means of Fig. 62 of the Instruction Book, determine 
the most suitable total flux to be applied for this single 
phase alternator. It is to be noted that on account of this 
machine being single phase the most suitable flux will 
correspond to an output which is about 30 per cent. higher 
than the actual one. 
An average form factor of k = 2.0 being assumed, calculate 
by means of Equation 35 of the Instruction Book the 
necessary number of armature-ampere-conductors corre- 
sponding to the flux ascertained in the preceding question. 
Calculate the full load current and determine the approxi- 
mate number of total armature conductors. 
The total number of slots, of which only 24 contain the 
armature winding, being fixed at 36, determine the number 
—=—- —_— Se eS 
