<p>In one aspect, the invention provides a residual current device (RCD) for protecting a circuit by tripping in response to an imbalance signal representative of residual current imbalance in the circuit. The RCD trips the circuit when the imbalance signal exceeds a predetermined threshold rating. The RCD comprises test means for increasing the imbalance signal so as to test operation of the RCD against the rating. In another aspect the RCD comprises: a current transformer for generating an imbalance sense current in a sense coil in response to a current imbalance in an electric supply; and a degaussing coil for substantially removing remanence in the current transformer by application of a degaussing signal to the degaussing coil.</p>
申请公布号
WO2004042882(A1)
申请公布日期
2004.05.21
申请号
WO2003GB04833
申请日期
2003.11.10
申请人
EATON ELECTRIC LIMITED;JACKSON, JONATHAN, KEITH;WILLIAMS, ANDREW