Patent ID: 7944654

Claim:
A multi-pole circuit breaker for a power distribution system having multiple line conductors carrying AC currents that are out of phase with each other from a source to a load, comprising a first current sensor adapted to be coupled to both of said line conductors and to said neutral conductor and producing a first output signal indicative of the sum of the electrical currents flowing in said line conductors from source to load, a ground fault detection circuit receiving said first output signal and producing a trip signal in response to the detection of a ground fault, a second current sensor comprising a coil wound on a hollow core with both of said line conductors passing through said hollow core in a manner that the electrical currents in said line conductors induce in said coil a second output signal that is a function of the difference of the electrical currents in said line conductors, and an arcing fault detection circuit receiving said second output signal and including a processor programmed to analyze said second output signal and produce a trip signal in response to the detection of an arcing fault.