OPERATING AND MAINTENANCE INSTRUCTIONS 753 



He will know that all operations, such as the starting and stop- 

 ping of generators, handling of switches, etc., will be carried 

 on exactly the same as on any other shift. 



A good example of the result of study and system in oper- 

 ating methods is the comparatively simple matter of starting 

 up a generator. Before the instructions were put into effect the 

 time for starting a unit would vary from 1J to 3 or 4 minutes, 

 depending upon the individual operators and hydraulic attend- 

 ants. A study was made of the various operations and the time 

 taken to start a generator, and it was found that by having the 

 several attendants do their work independently, without waiting 

 for one another and without waiting for verbal instructions, 

 operations could be performed simultaneously which were for- 

 merly done successively. It had been the practice for the gov- 

 ernor man to make an imspection of the unit and for the opera- 

 tor to try out the oil switch, before the disconnectors were 

 closed. These unnecessary precautions were eliminated by in- 

 sisting that every unit and oil switch, in fact every part of the 

 equipment, be ready for immediate service at any moment, unless 

 it was covered by a " hold-off " tag. The operation of starting 

 the unit on the governor also took time, and it is now the practice 

 to start the unit on hand control. The best way of manipulating 

 the gates to get the unit to accelerate more rapidly was observed, 

 and the governor attendants instructed accordingly. 



It has also been made the practice to always start the units 

 quickly. The normal time now taken to start a unit is about 

 sixty seconds. The record time on a stop-watch drill test was 

 forty-one seconds, while in an actual emergency due to the loss of 

 a steam turbine unit on the system, and resulting in frequency 

 disturbance, a unit was paralleled and frequency brought to nor- 

 mal in thirty-five seconds after the disturbance occurred. In 

 another case two units were paralleled and frequency brought to 

 normal 1J minutes after the trouble. 



An important feature of this quick starting is that it must 

 accelerate very quickly at first and pass through the synchronous 

 point very slowly. While the unit is accelerating the operator 

 must send his assistant to close the disconnecting switches and 

 have his synchronizing and voltmeter plugs in position before 

 the unit comes up to speed, so that as soon as the speed passes 

 through the synchronous point he gets his " shot." If he misses 



