Paired-phase bus bars for large polyphase currents

THE design of efficient conductor systems for large alternating currents has always been a problem, and the problem is especially difficult with large low-voltage polyphase currents, such as are found in feeder distribution systems for industrial plants. Special conductor shapes and arrangements have been proposed in the past and have proved satisfactory for some applications, but all have had their limitations. A new method of arranging bus bars, named paired phasing, has now been developed and has been found to be superior to conventional arrangements for transmitting polyphase currents in the range of 1,000 amperes and above, at 600 volts and less.