Patent ID: 7606298

Claim:
A method of testing a power line carrier pick-up coil while the pick-up coil is connected to an energized first power distribution bus in a power distribution network, the method comprising: creating a connection between a first pick-up coil to a power line carrier receiver to communicate analog signals conveyed by power line carrier from a power line carrier transmitter at a remote location over a first phase of the first power distribution bus, the analog signal conveyed from a point of injection on a secondary side of a transformer across the transformer to a primary side of the transformer; through a closed breaker; through a primary fuse; over a feeder bus; through a closed substation breaker and to the first pick-up coil; receiving analog signals at the first pick-up coil and conveying the analog signals to the power line carrier receiver; initiating a pick-up coil test to include testing of the first pick-up coil while the first power distribution bus remains energized; applying a set of at least two test inputs, each test input have a test frequency such that at least two different test frequencies are applied to the connection between the first pick-up coil and the power line carrier receiver and monitoring the response from the first pick-up coil on the connection between the first pick-up coil and the power line carrier receiver, the set of at least two test frequencies including at least one closest test frequency that is the closest of the various test frequencies to an expected resonance frequency for the first pick-up coil; and comparing: a response of the first pick-up coil to a closest test frequency with; a set of responses to a set of at least one test frequency that is not the closest test frequency to determine whether the first pick-up coil is exhibiting resonant behavior.