MAINTENANCE 



153 



have a spare telephone on each reserve, which can be temporarily installed while a 

 telephone or the part of it that is out of order is sent to some reliable telephone man 

 for inspection, repair or readjustment. 



In general, telephone trouble may be in connection with (1) signalling or (2) 

 talking and hearing. The generator furnishes current for signalling or ringing the 



Fig. 97 Wiring of No. 1317 telephone set 



bells, sending a current over the line to all bells on its way to the ground. The 

 generated current is intermittent, and jumps to the ground or is greatly weakened 

 by groundings instead of flowing along the line. The batteries furnish current for 

 conversation only. It is possible to talk over a wire even when there are slight 

 grounds through trees or through the line wire touching the ground in dry places, 

 .but it is not possible to signal. 



3 GUIDE TO CLEARING TROUBLE 



Trouble No. I, Bell Cannot ring up anyone; generator handle turns hard; local bell 

 does not ring when generator is turned. 



Cause. Protector burned out or dirty. Line wire grounded or wires crossed (ii 

 metallic) ; improper wiring in set or bushings on generator carbonized. 



