Abstract :
R. B. Williamson: The testing of large generating units after they have been installed in the power station is becoming more common than was formerly the case because the great increase in size has rendered satisfactory factory testing very costly; in many cases it is, in fact, impracticable because the machines are not completely wound and assembled at the factory. There is no doubt that a great deal of money has been expended in the past on unsatisfactory factory tests that could have been made to much greater advantage after installation. Any methods of testing, therefore, that are of advantage when machines have been set up ready for use are worthy of very careful study and we are much indebted to Mr. Johnson for the present paper which shows the application of the retardation method to some of the largest hydroelectric units so far built.
