| 摘要 |
PURPOSE: To provide an enclosed switchboard which contribute to safety by a method wherein a pressure-discharge plate for a bus chamber is installed at the rear of the enclosed switchboard, a bellows-constitution steel-plate passage which is always contracted is installed, the passage is expanded by the pressure of a gas discharged via the pressure-discharge plate in the short circuit of the bus chamber and the gas is discharged to the upper part. CONSTITUTION: A bus-chamber pressure discharge plate 20 is installed on the side of a rear door 21 from a bus chamber 19, and a bellows-constitution steel- plate passage 22 is installed on the front of the bus-chamber pressure-discharge plate 20. The passage 22 is expanded by an abnormal pressure at the inside of the bus chamber, it is moved up to a position 22a, and it is stopped at the safe position 22a by a safety pole 23. When the passage 22 is expanded to the position 22a, a gas which is generated in a short circuit can be discharged smoothly, and the safety of an enclosed switchboard can be enhanced. |
