Abstract: In a method for detecting a motor phase fault of a motor arrangement, the motor phases of which are connected to a drive circuit having a DC voltage intermediate circuit and an inverter. A motor phase voltage at at least one of the motor phases with respect to a reference potential is captured while the inverter is switched off; and a voltage profile of the captured motor phase voltage is used to determine whether there is a motor phase fault on one of the motor phases of the motor arrangement.

Abstract: A drive circuit for driving an electronically commutated motor contains a DC voltage intermediate circuit, and an inverter which is connected to the latter and has a bridge circuit containing a plurality of transistors, to which the motor phases of a motor configuration containing the motor can be connected. For detecting an insulation fault in the motor configuration, a positive or negative transistor of the inverter is switched on, while all other transistors of the inverter are switched off before all transistors of the inverter are switched off. A motor phase voltage of a selected motor phase of the motor phases with respect to a reference potential is then captured, while all transistors of the inverter remain switched off in order to determine whether there is an insulation fault on the motor phase on a basis of a voltage profile of the motor phase voltage.

Abstract: A drive circuit for driving an electronically commutated motor includes an AC terminal to which a power supply grid is connectable, a rectifier connected on the input side to the AC terminal, an inverter connected on the input side to the rectifier and to which the motor phases of the motor are connectable, and an intermediate DC voltage circuit between the rectifier and the inverter. An EMC filter includes a capacitive feedback coupling having at least one Y-capacitor connected between one pole of the intermediate DC voltage circuit and protective ground and overall incorporating stronger insulation than basic insulation.

Abstract: A drive circuit for driving an electronically commutated motor contains a DC voltage intermediate circuit, and an inverter which is connected to the latter and has a bridge circuit containing a plurality of circuit breakers, to which the motor phases of a motor configuration containing the motor can be connected. For detecting an insulation fault in the motor configuration, a positive or negative circuit breaker of the inverter is switched on, while all other circuit breakers of the inverter are switched off before all circuit breakers of the inverter are switched off. A motor phase voltage of a selected motor phase of the motor phases with respect to a reference potential is then captured, while all circuit breakers of the inverter remain switched off in order to determine whether there is an insulation fault on the motor phase on a basis of a voltage profile of the motor phase voltage.

Abstract: In a method for detecting a motor phase fault of a motor arrangement, the motor phases of which are connected to a drive circuit having a DC voltage intermediate circuit and an inverter. A motor phase voltage at at least one of the motor phases with respect to a reference potential is captured while the inverter is switched off; and a voltage profile of the captured motor phase voltage is used to determine whether there is a motor phase fault on one of the motor phases of the motor arrangement.