| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the need for laying a neutral line separately from a trunk, drastically simplifying a layout operation, and reduce costs by using a cable-shield layer along the trunk of a power distribution line as the neutral line of a three-phase four-line system power distribution line. SOLUTION: A bypass cable 14 with three cable-shield layers is connected to three trunks 12 via a pull-down cable 15 for a trunk, and at the same time the cable-shield layer of the bypass cable 14 is electrically connected to the neutral line 13. In this case, a wire shield where thirty soft copper wires with a diameter of approximately 1.0 mm are wound in crosswise direction as a shield layer is used. Then, with the connection between the cable-shielding layer and the neutral line 13, the neutral line 13 is connected to a switcher 17 being inserted between the bypass cable 14 and the pull-down cable 15 by a pull-down cable 19 for the neutral line, thus eliminating the need for newly laying the bypass cable for the neutral line, simplifying the laying operation, and reducing costs. |
