Patent ID: 11697574

Abstract:
The invention relates to an elevator comprising at least one elevator car moved by at least one elevator motor, which elevator motor is driven by a frequency converter controlled by a control device of the elevator, the frequency converter comprising a rectifier bridge, an inverter bridge and a DC link connected in-between, the inverter bridge being connected to the elevator motor and the rectifier bridge being connected to AC mains via three phase supply lines comprising an LCL-filter and a mains switch. The elevator further comprises a backup power supply and a safety device of the control device, which in case of a mains power failure is configured to switch off the mains switch and to connect the backup power supply to the DC link and/or to at least one phase supply line, whereby the rectifier bridge is a bidirectional rectifier bridge being configured to convert DC supplied to the DC link from the backup power supply to an AC voltage supplied to at least two of the phase supply lines connected with at least one load circuit. An earth fault protection circuit for the load circuit is connected between earth and a common terminal of the capacitors of the LCL filter for monitoring an earth fault indicating signal, and which earth fault protection circuit is configured to issue an earth fault signal and/or initiating earth fault safety measures, dependent on the earth fault indicating signal.