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BELL SYSTEM TECHNICAL JOURNAL 



Direct Metallic Circuit Induction in Untransposed Telephone Circuits 



Magnetic Induction, 1000 Cycles 



Volts Metallic per Ampere of Power Circuit Current per 1000 Feet of Exposure 



* In each case, conductor "N" is a multi-grounded neutral, the other wires being 

 phase conductors. Assumed 50% of the residual current in the neutral and 50% in 

 the ground. 



Electric Induction 

 Volts per Kilovolt Vm/Kv 



t Wires S & S assumed continuous through exposure and grounded. 



Fig. 2 — Effect of relative positions on joint-use pole of power and telephone con- 

 ductors on coefficients of induction for voltages and currents. 



However, by cooperative planning of routes it is frequently practicable 

 to secure lower coupling by avoiding long e.xposures between the main 

 feeds of the two plants. As shown by the illustrative examples this 

 procedure is, where applicable, very beneficial. 



