The residual current operated protector should be tested regularly

however

the operation characteristic test will cause a large area of power cut.In this paper

a device for judging the operation effectiveness of residual current operated protector without power cut-off is presented. The data of the residual current operated protector are obtained through the standard specification by the device

and the data sampled by the monitoring terminal itself are compared

whether the data collected by the residual current operated protector is normal or not and whether there is the situation of rejecting or misoperation are analyzed and judged. The validity of the method is tested through practical application and test.