30° ALTERNATING GENERATORS AND SYNCHRONOUS MOTORS. 
equals 26,000 lbs. The total weight of the alternator 
.. 1° without exciter will then amount to 38,000 lbs. 
From Fig. 15, the cost of the copper will equal 2,000 shil- 
use lings; the cost of the finished and annealed stampings for 
«ui ov the armature coil will equal 2,400 shillings; and that of 
the castings and auxiliaries 3,300 shillings. The total 
material cost of the alternator will then equal 7%,'700 shil- 
lings. The rates given in Fig. 15 are based on modern 
workshop methods and the standard scale of wages cus- 
Ny 
~*~ mee: 
. we? ai 
R . ie 
‘Ce 
O 700 200 300 40g 300 G00 000 800 G00 7000 
OOTP UT IN KVA. 
Fie. 16.—CurvE oF RATIO BETWEEN MATERIAL AND LABOR COSTS. 
oF STANDARD MEDIUM SPEED, 50 CYycLE, POLYPHASE 
ALTERNATORS. 
tomary and cost of materials in England. Similar curves 
can be readily plotted for costs in other countries. 
From the curve Fig. 16, the ratio between material and labor 
_ cost for the generator under consideration, is about 3 to 1, 
from which the shop labor costs of 2,550 shillings are ob- 
tained, where M and L equal material and labor, respec- 
tively. 
It may be pointed out, that the greater the capacity of the 
secs. aiternator the greater will be the ratio M = L. | 
. 
a * 
