General considerations in grounding the neutral of power systems: The neutral grounding reactor: Operating performance of a Petersen earth coil: Present day practise in grounding transmission systems: Systems transmitting at generated voltage: Systems transmitting at higher than generated voltage

R. W. Atkinson: I want to say a word with regard to the comparison between the condition of a cable system and an overhead open-wire system with regard to the grounding of the neutral. There is a large and important difference for two reasons. The most important reason is the relative cost of insulation of the cable system as compared with the overhead cable for high voltage. The insulation is a very important part of the transmission system, whereas it is a relatively minor part in the overhead system. You can afford in the overhead system to put on insulation to take care of the voltage rise due to abnormal conditions, and you can afford to put on the insulation to take care of service conditions; whereas the same difference in service conditions costs you a whole lot more in insulation of cable systems. Another difference from the standpoint of operation, is the very much greater electrostatic capacity for the cable system.