| 摘要 |
PROBLEM TO BE SOLVED: To provide a tap change-over unit under load high in reliability of operation in a small-sized and simple constitution. SOLUTION: In the tap change-over unit under load comprising a change-over switch for changing over a plurality of taps having a tap winding of a transformer from one tap to an adjacent tap and a tap selector provided with a mobile contact selecting a fixed contact connected to the tap at a required position, a change-over switch is attached to a drive shaft 146 rotated by drive force given from outside, has a wheel 252 having a plurality of grooves 252a and 252b of prescribed widths in the direction of the plate thickness along a circumferential direction, a vacuum valve is provided to correspond to the grooves 252a and 252b of the wheel 252 and an opening and closing mechanism 230 for opening and closing the vacuum valve in response to existence of the grooves 252a and 252b accompanying rotation of the wheel 252 is provided between the wheel 252 and the vacuum valve.
|
