SWITCHING EQUIPMENT 



547 



TABLE L 

 DIRECT CURRENT 



(a) On multiple-circuit feeder panels controlling feeders of small capacity, am- 

 meters are usually omitted. 



(6) On small motors, ammeters are usually not furnished. 



(d) Where there are only two exciters operating in parallel, one voltmeter is used 

 on each exciter equipment. Where there are three or more exciters, two voltmeters 

 are employed and mounted together on a swinging bracket at the end of the board, 

 usually on the same bracket containing the alternating current voltmeters and syn- 

 chronism indicator. One is connected to the bus and the other is arranged to be 

 plugged to any machine to read voltage at any time. In many instances exciters are 

 direct connected or belted to the alternating-current machines, the fields of which they 

 excite, and are not operated in parallel, no separate panels being furnished to control 

 them. In such cases no measuring instruments are furnished, the field ammeter of 

 the alternating current machine taking the place of the exciter ammeter, while 

 there is ordinarily no use of the voltmeter. 



* Where the different types of circuits given in the first column occur In the same 

 board, only one voltmeter need be supplied, providing the scale is suitable for the volt- 

 age of all circuits to be measured. 



t Due to the large number of methods of connecting batteries, no definite instru- 

 ment equipment can be listed to apply to all cases. The above represents a simple 

 equipment for measuring charging and discharge current and voltages as indicated. 



