Single phase circuit breaker with an electrical power conversion system for converting a high voltage from a HV electrical power supply phase to a low voltage, wherein the electrical power conversion system comprises: at least one power converter, at least one RC network comprising a plurality of resistive components (R1, R2, R3) and a plurality of capacitive components (C1, C2, C3) electrically connected in series, wherein the at least one RC network is in series connection with the at least one power converter, wherein the power converter has a rectifier for rectifying a current provided by the RC network, and the at least one RC network and at least one power converter are arranged to be connected across a line potential of the HV electrical power supply phase, charcterised in that, the electrical power conversion system further comprises a voltage sense module, wherein the voltage sense module: comprises a resistive component and a capacitive component connected in series with each other and with the at least one power converter, is arranged to correct a phase shift introduced by the RC network, such that the voltage output of the voltage sense module is in phase with the line voltage signal of the HV network phase, is adapted to measure a current flowing through the RC network and to convert the current to a sensor voltage value for the circuit breaker electronics, thus providing a system for monitoring the status of the phase-ground voltage and further comprises a voltage loss correction module, wherein the voltage loss correction module is adapted to correct the sensor voltage value based on voltage losses caused by the power converter, the single phase circuit breaker further characterized in that it has an on-board micro-processor control and wireless connectivity, has configurable protection, multi-phase operation functions, on-board event history and can be integrated into a SCADA system for remote control. at least one power converter, at least one RC network comprising a plurality of resistive components (R1, R2, R3) and a plurality of capacitive components (C1, C2, C3) electrically connected in series, wherein the at least one RC network is in series connection with the at least one power converter, wherein the power converter has a rectifier for rectifying a current provided by the RC network, and the at least one RC network and at least one power converter are arranged to be connected across a line potential of the HV electrical power supply phase, the electrical power conversion system further comprises a voltage sense module, wherein the voltage sense module: comprises a resistive component and a capacitive component connected in series with each other and with the at least one power converter, is arranged to correct a phase shift introduced by the RC network, such that the voltage output of the voltage sense module is in phase with the line voltage signal of the HV network phase, is adapted to measure a current flowing through the RC network and to convert the current to a sensor voltage value for the circuit breaker electronics, thus providing a system for monitoring the status of the phase-ground voltage and further comprises a voltage loss correction module, wherein the voltage loss correction module is adapted to correct the sensor voltage value based on voltage losses caused by the power converter,