| 摘要 |
<p>A fault-current protection switch comprising a summating current transformer (10), to whose secondary winding (11) is connected the trip coil (26) both directly and also via an electronic circuit (13), so that both a.c. and d.c. fault currents, and a.c. fault currents with d.c. components can be detected and used for switching off a mains circuit.</p> |
