ELEVATOR SAFETY MONITORING SYSTEM, ELEVATOR SYSTEM, ELEVATOR DRIVE UNIT, AND METHOD FOR OPERATING AN ELEVATOR

摘要

An elevator safety monitoring system, an elevator system (100), an elevator drive unit (35), and a method for operating an elevator are presented. The elevator safety monitoring system comprises an elevator car absolute position and speed feedback device (60), a safety monitor (40) connected to the absolute position and speed feedback device (60), and a safety zone (104) extending inside an elevator shaft (12). The safety zone (104) is associated with an allowable maximum speed (412) of an elevator car (10), wherein the allowable maximum speed (412) is lower than a rated speed (411) of an elevator car (10) outside the safety zone (104), wherein the safety monitor (40) is configured to determine a slowdown failure of the elevator car (10) approaching the safety zone (104), and, upon the determination of the slowdown failure, command an actuator to decelerate the elevator car (10) to the allowable maximum speed (412).