| 摘要 |
PROBLEM TO BE SOLVED: To reduce in size and cost and to provide saving in space and maintenance by providing a cooling air channel for passing a cooling air from a cooler via a cooling air port of another end to an exterior, via a main circuit opening/ closing unit from one end of the port. SOLUTION: Air cooled by a blower 11 and a cooler 12 of a cooling device 10 is passed through a first duct 51 and introduced from a cooling air port 80a into a main circuit opening/closing unit 40. The air arrives at a cooling air port 90a of a first phase, passes through a duct 53 for forming a second cooling air channel, and flows into the unit 40. The air is made to flow out of a cooling air port 90c provided at the other end of a third phase to the outside of the unit 40, reach a second duct 54, and return to the device 10. Thus, since the air forcibly cools only the main circuit opening/closing device, a large blower capacity is not necessary, the device 10 can be reduced in size and cost, and a maintenance of the opening/closing unit is facilitated. |
