| 摘要 |
PURPOSE:To facilitate maintenance of a switchboard by exhausting the air by reversing a suction fan, and at the same time, removing dust adhering on a filter by brushing the outer face of the filter. CONSTITUTION:In normal time, the outside air is introduced into a box 1 by a suction fan 9 through a vent 4 and a filter 10 and after cooling electric parts 7, exhausted from an opening of a shielding plate 6 through dust guard plates 20, 5. In maintenance operation, the suction fan 9 is reversed to apply reverse pressure to the filter 10 and at the same time, a wiper 21 is operated. Then, air current in the box 1 is changed as shown by arrows 25-29, and the air is exhausted from the air vent 4 through the filter 10. A wiper rotating rod 22 is actuated by operation of the wiper 21 and a wiper brush 23 attached to it brushes the outer face of the filter 10. Thus, dust clogging the filter 10 is picked up and removed by exhaust air. |
