SWITCHBOARDS AND SWITCHBOARD APPLIANCES. 333 



transmission lines between the point of attachment of the lightning 

 arrester and the bus-bars in the station. 



Synchronous motor panels. A synchronous motor panel is 

 essentially the same thing as the alternating-current panel of a 

 synchronous converter, except that a synchronous motor panel 

 usually includes the switches and rheostats of a small direct-cur- 



High Tension Bus-b&rs \ 



\ I 



* i Hi$ A Tens/on * * 



Switches 



L, 



i i 



r r 



y 



Fig. 284. 



rent generator, the exciter. Thus the right-hand side of Fig. 285 

 shows the essential features of a three-phase synchronous motor- 

 panel, except that the exciter accessories are absent. Figure 280 

 shows the connections of a three-phase synchronous motor (2 A TY 

 2,300 V. 300 K.W.) with its field current supplied from the same 

 exciter that supplies field current to the main generator. This 

 synchronous motor is arranged to be started by inherent induc- 

 tion-motor action, as explained on page 271 and in this case no 

 synchronizing device is used. 



150. Voltage regulators. The simplest device for regulating 

 the voltage of a pair of feeders in a generating station, or for 

 regulating the voltage of alternating-current supply to a rotary 



