70 



CONSTANT-VOLTAGE TRANSMISSION 



IV. COMPARISON OF COSTS FOR 4-MILE LINES 



NOTE: As the above saving in copper could have been made by 

 using transformers for 6,600 or 11,000 volts, the constant- voltage 

 system would probably not be economical unless the voltage is 

 limited in some way to 2,200 volts, or unless contracts can be 

 made to obtain the required voltage control from the customers' 

 synchronous motors. See Chap. IX. 



