With the advancement of science and technology, the level of design, manufacturing, installation, inspection, repair, maintenance, and use of passenger elevator technology and management has been continuously improved, and the reliability of its operation has increased significantly. But in the maintenance, there are still some typical elevator stop failures, among which the failure of the safety circuit causes the elevator to fail the most.

1. The elevator stops due to phase failure

When the three-phase power supply is out of phase, the phase sequence relay will act to cut off the safety circuit and stop the elevator. This kind of failure is mostly caused by elevators controlled by relay logic. Because it is an old-fashioned elevator, the power switch is mostly knife-type, and the current of the elevator running and starting is very large. After a period of operation, if the maintenance personnel do not check in time, the fuse and the screw connection are easily blown, and the elevator loses the phase, causing the elevator to stop, ranging from shutting down the person to the accident. Maintenance personnel should conduct frequent inspections, find suspicious points, and repair them in time. If there are hot and sparks, they should be replaced immediately. It is recommended that the user replace the knife switch with an air switch of equivalent capacity. The elevators currently designed do not have power limit switches, and the safety circuit can be slightly modified, that is, add upper and lower limit electrical switches in series in the safety circuit, and remove the original limit switches.

2. The elevator stop caused by the disconnection of the rope pulley switch

Like a traction rope, the overspeed governor rope also stretches during use. Due to the action of the heavy hammer of the rope-raising wheel in the pit, the rope-raising switch is deflected until the switch is turned off and the ladder stops.

For this kind of failure, the maintenance personnel must check once a month for newly installed elevators. After one year of operation, check once every three months, so that the trouble can be prevented before it happens. Due to the poor sealing of the hall door and the wall hole in the hoistway, the elevator running downwards caused the safety gear to switch, and some speed limiter switches were also linked together. The fundamental solution to this type of failure is to prevent rats. Anti-rodent measures such as spraying appropriate rat medicines in the corners of the computer room and pit can be taken to reduce the occurrence of failures.

3. Failures caused by interlocking doors

According to the design requirements of the elevator: the elevator can start running only after the hall door and car door of each floor are closed. If any floor door or car door is not closed, the elevator cannot run. Because the door lock contacts are accumulated with dust and poor contact, it will cause sparks and cause the elevator to stop. It is good and bad, but the fault is not known. Because the engagement depth between the lock hook and the door lock block is too small, the door lock contact is not fully compressed, resulting in poor contact. The increase in contact pressure can avoid poor contact. Because the gap between the lock hook and the block is too large, if passengers pull the door outside the hall door, the rope break switch of the hall door will be disconnected and the elevator will suddenly stop during operation.

Such failures require maintenance personnel to frequently check the door lock contacts, gaps, whether the hall door wire rope is stretched, whether the door connecting rod is loose, and whether the door lock block hook is deformed or damaged. Find problems and eliminate them in time to reduce unnecessary elevator shutdown failures. In reality, the elevator stops running and people are locked in the car from time to time. As the elevator was shut down, the people in the car panicked, kicked and clashed randomly, causing damage to the elevator or personal injury or death. Therefore, reducing Passenger Elevator Factory stop failures is a very important issue for manufacturers.