摘要 |
A method and detection system monitors the speed of an elevator car and, in case of excess speed caused by brake failure of a motor brake or shaft fracture of a drive pulley shaft, a safety circuit is opened and the detection system is transferred from a normal operational state (State 1) to a retardation state (State 2) in which it is monitored whether the elevator car is retarded after defined speed presets. After a successful retardation, the detection system is transferred to a state of standstill monitoring (State 3) in which it is monitored whether the elevator car leaves its standstill position. If the presets of State 2 or State 3 are not fulfilled, the detection system is transferred to a braking state of the brake (State 4) in which a brake which fixes the elevator car is activated.
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