Elevator And Method For Performing A Manual Emergency Drive During Power Outage In An Elevator

Abstract: The invention relates to an elevator (10) comprising a manual active dynamic braking function, which elevator comprises an elevator control (46) for operating at least one elevator car (14) in at least one elevator driveway between landing floors in response to elevator calls, an AC elevator motor ( 12), which is able to generate power in a generator mode, a motor drive ( 22) connected to the elevator control (46) for the regulation of the speed of the elevator motor (14), comprising a frequency converter (24), whereby the frequency converter (24) of the motor drive ( 22) comprises a rectifier bridge (26) and an inverter bridge (32) with semiconductor switch circuits (70a - 70f), which rectifier bridge (26) and inverter bridge (32) are connected via a DC link (34), the motor drive ( 22) further comprising a drive controller (42) at least to control the semiconductor switches (72) of the semiconductor switch circuits (70a - 7 Of) of the inverter bridge (32) to regulate the elevator motor (12) to a reference speed, whereby the semiconductor switch circuits (70a - 70f) of the inverter bridge (32) are provided with diodes (74) connected anti-parallel to the semiconductor switches (72), the motor drive (22) comprises a safety logic (44) for cutting off control pulses to the semiconductor switches (72), at least during power outage, - at least one elevator brake (20a, 20b) is located in connection with the elevator motor ( 12) and/or with a traction sheave of the elevator motor (12), a manual brake release lever (50) is functionally linked (54) to the elevator brake (20a, 20b), movable between a rest position and at least one operating position to release the elevator brake (20a, 20b) manually. According to the invention the motor drive (22) comprises a bypass switch (56) being arranged to operate the safety logic (44), as to enable dynamical braking of the elevator motor (12) by connecting the semiconductors (72) of the semiconductor switch circuits (70a - 70f) of the inverter bridge (32) with the drive controller (42), and the motor drive (22) comprises a DC supply circuit (60) connected with the DC link (34), which is arranged to feed DC power at least to the drive controller (42) and to the bypass switch (56) to enable dynamic braking control of the semiconductor switches (72). The manual brake release lever (50) is functionally connected with the bypass switch (56) and (50) is arranged to operate the bypass switch (56), when it is moved away from its rest position. Alternatively the elevator (10) comprises a manual actuator (64), such as a key switch, disposed in the same location with the manual brake release lever (50), whereby the manual actuator (64) is arranged to operate the manual bypass switch (56).

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