Wireless current sensor designed for measuring an electrical current flowing in an electrical conductor, said wireless current sensor comprising: - a current transformer comprising a core designed to be arranged around said electrical conductor forming a primary of said transformer, and a winding made around the core and forming a secondary of said transformer in order to retrieve an electrical power when an electrical current flows in the electrical conductor, - an electronic circuit connected to the secondary of the transformer, the electronic circuit comprising: - means for storing the generated electrical power, - means for measuring the electrical current flowing in the electrical conductor comprising a microcontroller supplied by the electrical power stored in the means for storing electrical power and for generating measurement data of the electrical current flowing in the electrical conductor, - a wireless data transceiver (E/R) coupled to said microcontroller for sending the measurement data, characterized in that the current sensor comprises: - at least two distinct operating modes, the two operating modes differing from one another by the measurement data generated by the microcontroller and sent by the data transceiver (E/R) and by the duration of measurement of the electrical current flowing in the electrical conductor, - means for determining the transition from one operating mode to the other taking account of a value of said measured electrical current. - a current transformer comprising a core designed to be arranged around said electrical conductor forming a primary of said transformer, and a winding made around the core and forming a secondary of said transformer in order to retrieve an electrical power when an electrical current flows in the electrical conductor, - an electronic circuit connected to the secondary of the transformer, the electronic circuit comprising: - means for storing the generated electrical power, - means for measuring the electrical current flowing in the electrical conductor comprising a microcontroller supplied by the electrical power stored in the means for storing electrical power and for generating measurement data of the electrical current flowing in the electrical conductor, - a wireless data transceiver (E/R) coupled to said microcontroller for sending the measurement data, - means for storing the generated electrical power, - means for measuring the electrical current flowing in the electrical conductor comprising a microcontroller supplied by the electrical power stored in the means for storing electrical power and for generating measurement data of the electrical current flowing in the electrical conductor, - a wireless data transceiver (E/R) coupled to said microcontroller for sending the measurement data, - at least two distinct operating modes, the two operating modes differing from one another by the measurement data generated by the microcontroller and sent by the data transceiver (E/R) and by the duration of measurement of the electrical current flowing in the electrical conductor, - means for determining the transition from one operating mode to the other taking account of a value of said measured electrical current.