Abstract: A method for monitoring a circuit breaker, a system and an internet of things using the same are disclosed. The method includes measuring at least two operating condition related parameters of the circuit breaker during operation of the circuit breaker; obtaining first data representing a vector having at least two components respectively representing the at least two measurements of the at least two parameters; judging location of the vector represented by the obtained data with respect to a vector space having an envelope separating healthy and unhealthy status of the circuit breaker, where the envelope has at least one portion of curvature; and generating a signal indicating the health status of the circuit breaker in consideration of the location of the vector if it is outside of the envelope.