METHODS, DEVICES AND SYSTEMS FOR DETECTING AN INSULATION FAULT IN AN ELECTRICAL INSTALLATION

A method for detecting an isolation fault in an electrical installation comprises:measuring an AC electrical voltage between phase conductors of an electrical load to be monitored and ground, and an electric fault current flowing between said electrical load and ground;identifying, in the measured electrical voltage, at least one first component oscillating at the predefined first frequency and one second component oscillating at the predefined second frequency;calculating an impedance of the electrical fault from the measurements and an impedance of the electrical installation from the identified first and second components;selecting a predetermined case from a predefined list; andidentifying an operating condition of the electrical installation on the basis of the selected predetermined case.