| 摘要 |
PURPOSE:To reduce inspection work burden for a box type switchboard and to protect dust from entering into it when inspecting the board by mounting a dust-proof filter housing case to the outer surface of an aeration window section with hinges so that the housing case can open and close. CONSTITUTION:A U-shaped framework 16a and a porous board 16b fixed to one end face thereof form a housing case 16 for a dustproof filter 3. Next, the housing case 16 is fitted in the inner side of an inverted U-shaped rim 17 mounted on the outer surface of aeration window section 2a of door 2 via a porous board 4, in a manner that one end section thereof is connected to the rim 17 with a hinge 18 so that the framework 16a can be opened and closed. Further, a stopper 19 that appropriately controls the degree of opening of case 16 is installed in the rim 17. Thus, by slackening a screw 20 to open the case 16 outward, the filter 3 can easily be attached or detached externally without opening the door 2, and thereby an amount of dust that is liable to enter into the distribution board at the time of inspection of the filter can be reduced. |
