There is provided a current sensor for monitoring electrical disturbances on an electrical circuit having an electrical conductor. The current sensor comprises a magnetic flux sensor for sensing a magnetic flux generated by a current flowing in the electrical conductor and for providing a signal representative of the current; and a processor for acquiring the signal from the magnetic flux sensor, for detecting an electrical disturbance on the current and for providing electrical disturbance data. The current sensor may also comprise a ring-shaped magnetic structure for receiving the electrical conductor and an opening within the ring-shaped magnetic structure for receiving the magnetic flux sensor. The magnetic flux sensor being for sensing a magnetic flux generated in the magnetic structure by the current in the electrical conductor.