| 摘要 |
PURPOSE:To make easier the separation of surge suppressor at the time of pressure resistance test by earthing the one terminal of surge suppressor through switch. CONSTITUTION:The one terminal of the surge suppressor 9 is earthed with the interposition of a switch comprising the insulating cylinder 14, the permanent magnet contacts 16 and 16', and the operating handle 17 near the front door, and the other terminal is connected with the one insulated wire 12 on the front side of a box in a 3-phase short circuit manner, on the line side of the main circuit conductor. At the time of pressure resistance test in site, the test can be simply by pulling the handle to break the switch, in contrast with the conventional enclosed switchboard in which CR suppressor is housed requiring for taking conductor out of the back door each time test is made. |
