Elevator load bearing member wear and failure detection

摘要

An elevator load bearing member ( 22 ) monitoring device ( 20 ) has a controller ( 30 ) that applies a first signal ( 40 ) and a second signal ( 50 ) to at least one tension member ( 24 ) in the belt. The first signal ( 40 ) in one example has a plurality of pulses ( 42 ) of a selected amplitude and duration. The second signal ( 50 ) includes a series of pulses ( 52 ) having a second, shorter duration and lower amplitude. The first signal is useful for providing information regarding a wear condition of the load bearing member. The controller utilizes a response to the second signal to determine a failure condition such as a broken load bearing member.