Open conductor detector system

An open phase conductor detector system consisting of one or more transmitters and a receiver which communicate through the distribution line neutral conductor is described. The design holds a promise to provide reliable protection for most down and open 5 to 35 kV distribution phase conductors in contact with high impedance surfaces. The transmitter(s) detects the open phase conductor by monitoring the phase conductor voltage using redundant inputs. When an open phase conductor is detected, the transmitter injects a signal to the distribution line neutral conductor by means of a coupling current transformer. The signal is frequency and duration coded. The receiver decodes the signal and generates a trip signal which may activate a breaker, a ground switch, or a recloser, causing isolation of the distribution line with the open (downed) phase conductor. The system is presently implemented for single distribution lines. A prototype open conductor detector system has been constructed and field tested on a Georgia Power Company distribution system