Hello everyone, I'm Andy, an R&D engineer at Delinbao Elevator. Here's my technical presentation for elevator professionals.

              Technical Insights on Elevator Door Malfunctions Involving Repeated Opening and Closing Cycles

Elevator Light Curtain Malfunction: There are two installation methods for elevator light curtains. The first involves mounting the light curtain on the car door panel so it moves with the door. The advantage is simple installation without occupying shaft width space. The disadvantage is that frequent movement can cause internal damage to the light curtain wires, leading to poor contact. This results in signal loss during door movement, sending an erroneous signal to the elevator. The second method involves mounting the light curtain fixed to the elevator car. The advantage is that the signal cable remains stationary, preventing damage. The disadvantage is that replacement becomes more complex later on. Elevator light curtains have a limited lifespan. They operate by transmitting infrared signals from one end and receiving them at the other. When any infrared emitter is blocked, it signals the elevator that an obstruction is present, triggering the door-opening sequence. After prolonged use (e.g., over five years), infrared signal strength degrades, necessitating timely replacement.

Another scenario occurs when the elevator's light curtain detects an obstruction during the closing process. In this case, inspect the elevator's closing path to determine if any obstructions are blocking the sensor.