The invention relates to a motor drive comprising a rectifier bridge for connection with mains, a converter bridge configured to be connected with an elevator motor and an intermediate DC circuit in-between, whereby between a positive and a negative branch of the intermediate DC circuit at least one capacitor and/or battery is connected,whereby at the mains side of the rectifier bridge a controlled main relay with contacts is arranged, which are configured to connect or disconnect the rectifier bridge with the corresponding mains phase, characterized in that the motor drive comprises a charging circuit being connected between the mains and the rectifier bridge and/or intermediate DC circuit, which charging circuit comprises at least one charging switch connected in series with at least one current limiting component, and which motor drive comprises a voltage sensor connected between the positive and the negative branch of the intermediate DC circuit, which voltage sensor is connected to a fault evaluation circuit comprising at least one reference value and a comparator, which evaluation circuit is configured compare the actual sensor signal of the voltage sensor to the reference value and to operate the main relay dependent on the comparison result.