POWER PLANTS FOR TELEPHONE OFFICES 



713 



be safely decreased, permitting advantage to be taken of appreciable 

 savings in the cost of battery equipment. 



Simplified Installation 

 The developments just discussed will, it is believed, simplify the 

 work of Installation, although certain of these developments will not 

 necessarily decrease the amount to be done, as some of the work has 



Fig. 8 — Commercial type charging generator driven by synchronous motor. 

 52-kw. output compares with 33 kw. for the larger sized set on the right. 52-kw. 

 "M" type generator in left background belted to gas engine. 



been shifted from installer to factory and some in the reverse direction. 

 The unit ringing control panel assemblies, for example, are being 

 furnished wired in the shop with rows of terminal punchings to which 

 the installer connects the wires from the generators. For charging 

 equipment, the panels at the machines will be connected to a common 

 overhead bus bar system, bus bars being shipped in stock lengths and 

 cut by the installer as needed. 



For small repeater and similar installations a power plant has been 

 developed which can be placed upon shelves on a rack and connected 

 to the power source and to the distributing bus bars. This compares 

 with the former system of installing a number of separate units and 

 wiring them up upon the job. 



