Elevator comprising - an elevator motor - a motor drive for the elevator motor having a frequency converter comprising a rectifier bridge , an inverter bridge and a DC link in between, which frequency converter is controlled via a controller , the rectifier bridge being connected to AC mains via three feed lines (38a-c) comprising chokes (44a,b), and the rectifier bridge being realised via controllable semiconductor switches (17a-f), - an isolation relay being located between the feed lines (38a-c) and AC mains , - a backup power supply at least for emergency drive operation, - an emergency control for performing an automatic emergency drive, - the backup power supply is via a first switch connectable with only a first of said feed lines (38a-c), characterized in that - a second and/or third (38b,c) of said feed lines (38a-c) is via a second switch (54a,b) connectable as power supply to a car door arrangement , while the second and third feed lines (38b,c) are separated from AC mains with the isolation relay , and - the first switch as well as the second switch (54a,b) are controlled by the emergency control , and in that the elevator comprises: - a first feedback circuit configured to provide to the emergency control first information indicating the switching state of the isolation relay , - a second feedback circuit which is configured to provide to the emergency control second information indicating switching state of the first switch , and in that the emergency control is configured to selectively allow or prevent the emergency drive operation on the basis of the first information and the second information. - an elevator motor - a motor drive for the elevator motor having a frequency converter comprising a rectifier bridge , an inverter bridge and a DC link in between, which frequency converter is controlled via a controller , the rectifier bridge being connected to AC mains via three feed lines (38a-c) comprising chokes (44a,b), and the rectifier bridge being realised via controllable semiconductor switches (17a-f), - an isolation relay being located between the feed lines (38a-c) and AC mains , - a backup power supply at least for emergency drive operation, - an emergency control for performing an automatic emergency drive, - the backup power supply is via a first switch connectable with only a first of said feed lines (38a-c), - a second and/or third (38b,c) of said feed lines (38a-c) is via a second switch (54a,b) connectable as power supply to a car door arrangement , while the second and third feed lines (38b,c) are separated from AC mains with the isolation relay , and - the first switch as well as the second switch (54a,b) are controlled by the emergency control , - a first feedback circuit configured to provide to the emergency control first information indicating the switching state of the isolation relay , - a second feedback circuit which is configured to provide to the emergency control second information indicating switching state of the first switch , and in that the emergency control is configured to selectively allow or prevent the emergency drive operation on the basis of the first information and the second information. <EOS>