| 摘要 |
PURPOSE:To allow one operator to handle a conduction testing for a low voltage circuit without shuttling between the substation and the job site by controlling d.c. voltage between an a.c. power source neutral conductor and the ground according to the presence of a.c. voltage on a panel board. CONSTITUTION:When an inspection is made to learn to which of several main switches 3 the third lamp panel board, 5 for example, of a plurality of panel boards is connected ina substation, a power switch 9 is turned on and actuates a DC relay 11 to open a b contact 11'. Then, a switch 12b of a DC-DC converter 12 is turned on. Then, while all of the main switches 3 are opened sequentially in the substation, d.c. voltage is detected with a tester 13 or a low voltage detector 14 for each one between the primary and secondary terminals of the neutral line. Those main switches 3 connected to the panel boards other than the third lamp panel boards 5 indicates 0V whereas the one connected to the third lamp panel board 5, d.c. current. This allows only one person to detect the connection state of the panel boards very easily. |
