| 摘要 |
<p>1. Earth fault current circuit breaker, the core of the core balance transformer (4) of which is premagnetised by a quiescent current derived from the system to be monitored by way of a feed circuit (8), wherein a variation of the magnetic flux in the core due to a fault current so changes the electrical resistance of the tripping circuit (9) that there can flow therein a current causing the tripping relay (3) to operate, characterised in that provision is made in the feed circuit (8) or in the tripping circuit (9) for suppressing the first half-cycle of the premagnetising current after restoration of the mains supply.</p> |
