748 ORGANIZATION AND OPERATION 



of the departments under consideration, a position is warranted 

 for a man to whom both electric and hydraulic superintendents 

 will report, thus still bringing the responsibility of operation of the 

 two departments under one head. 



As a general rule, for the same capacity installed, a plant 

 having horizontal units can get along with a smaller force than one 

 using vertical units. It is a general practice to maintain one man 

 at all times on each of the different levels or floors of the power- 

 house, such as the switchboard gallery, the main floor and the 

 basement, where with vertical units the turbines proper, as well 

 as the oil pumps and other auxiliaries are located. The man in 

 the basement could, in all probability, be dispensed with in plants 

 using horizontal units. In addition to these men a chief operator 

 should be provided for each shift, whose duties should carry him 

 to all parts of the building. For a very large station the above 

 force may be entirely inadequate, and for small plants the force 

 may be reduced. 



The switching operations are determined by the general method 

 of operation. It is desirable to eliminate all high-tension switch- 

 ing under load, due to the fact that such switching may set up 

 surges which may discharge into the transformers and cause 

 resonance, resulting in internal disturbances in the same. When 

 a line is to be cut into service, the high-tension switches in the 

 main and substation should be closed first, then the low-tension 

 transformer switch in the generating station should be closed, 

 energizing the transformers and the line, after which the low- 

 tension transformer switch in the substation is closed and the load 

 picked up. In case it becomes necessary to open a high-tension 

 switch in a loaded line, the circuit should, if possible, first be 

 parallel with another before opening the switch. If, on the other 

 hand, transformers are to be paralleled on both high- and low- 

 tension sides, the low-tension switch should be closed first, assum- 

 ing that the low-tension bus is energized. Similarly, in cutting 

 out the transformer the low-tension switch should be opened last. 



Operating Records. One of the essential things in connection 

 with the operation of hydro-electric generating stations is the 

 keeping of accurate records. Record sheets should contain only 

 the most important readings, as with complicated forms the 

 attendant generally realizes that a large number of the readings 

 are of no importance and for this reason he becomes very lax in 



