Patent ID: 8339275

Claim:
An apparatus for inducing tracing signals in a branch circuit conveying a power signal, said branch circuit having an associated circuit interrupter, and for detecting the induced tracing signals to identify the branch circuit, comprising: a controllable transmitter circuit configured to induce one or more tracing signals in the branch circuit; a phase detector circuit configured to detect a known phase point of a power signal conveyed on the branch circuit; a transmitter controller that causes the controllable transmitter circuit to induce the one or more tracing signals in the branch circuit at predefined times that are measured with respect to the detected known phase point of the power signal conveyed on the branch circuit; and a detector circuit configured to detect the known phase point of the power signal conveyed on the branch circuit, the detector circuit including a detector controller operable to determine a time window of predetermined duration sufficient to encompass the tracing signal at only the predetermined times that are measured with respect to the known phase point of the power signal conveyed on the branch circuit and to generate an indicator signal when the tracing signal is detected during the time window.