| 摘要 |
<p>The earthing switch includes a conductive arm (2) which is pivoted at one end and which carries a movable contact (21) at the other end. Current loop produce self-cancelling forces acting on the movable contact when a short circuit occurs. The fixed contact (18) is carried by a U-shaped holder (17) and is connected to the 2 arms of the U by a conductor and insulator respectively. When the switch is closed, the movable contact engages the fixed contact neat the insulated arm of the U to form a current loop from the controlled circuit to the movable contact vie the centre of the base of the U and the other (conductive) arm.</p> |
