Analysis and prevention of the most common elevato

Analysis and prevention of common elevator stopping faults

with the progress of science and technology, the level of elevator technology and management in design, manufacturing, installation, inspection, repair, maintenance, use and other aspects continues to improve, and the reliability of its operation is significantly increased. However, in the maintenance, there are still some typical elevator stopping faults, most of which are caused by the failure of the safety circuit

I. elevator stop caused by phase failure

when phase failure occurs in the three-phase power supply, the phase sequence relay acts to cut off the safety circuit and stop the elevator. This kind of fault mostly occurs in the elevator controlled by relay logic. Because it is an old elevator, the power switch is mostly knife switch type. The power supply passes through the limit switch and then is sent to the elevator control cabinet. The power supply flows through two switches, with a total of six fuses. When the elevator runs and starts, the current is very large. After a period of operation, if the maintenance personnel do not check in time, the fuse and screw connection is very easy to burn out, and the elevator phase breaks, causing the elevator to stop, which is light to close people, and heavy to an accident

main preventive measures: a. the maintenance personnel should regularly patrol and inspect, and repair in time if suspicious places are found. In case of scalding, sparks and other situations, they should be replaced immediately. b. It is recommended that the user replace the knife switch with an air switch of equivalent capacity. c. At present, the designed elevators do not have power limit switches. The author believes that the safety circuit can be slightly changed, that is, 15. Different force units (n, KGF, GF) can be selected to install upper and lower limit electrical switches in series in the safety circuit, and the original limit switches can be removed. After B.C. treatment, this fault can be completely eliminated

II. The opening of the rope sheave switch causes the elevator to stop

like the traction rope, the governor rope will also extend during use. Due to the action of the heavy hammer of the rope sheave in the pit, the plate of the rope sheave switch is offset until the switch is disconnected, causing the ladder to stop

for this kind of fault, for newly installed elevators, the maintenance personnel must check it once a month, and once every three months after one year of operation, so that it can be prevented

the author has encountered several phenomena that caused the mouse to fall into the pit and jump into the rope sheave, causing the three switches to act at the same time. Due to various reasons such as the lax sealing of the hall door and the wall hole in the shaft, some rats will fall to death when fleeing into the shaft, and some will fall into the pit and get stuck in it because they try to escape into the rope sheave. The downward movement of the elevator leads to the action of the safety gear switch, and some speed governor switches are also linked together. There is also a mouse running into the speed governor in the machine room, causing the above failure. The fundamental solution to this kind of failure is to prevent rats, which can be sprayed on the machine room and the corner of the pit, with an appropriate increase of $0.010/ton (15180000 tons); South Africa to China 5.5 (6) US $5/ton (15180000 tons); Iran to China 9.5 ⑴ 0.5 US dollars/ton (2 ⑶ 10000 tons) rat drugs and other rat prevention measures to reduce the occurrence of failures

III. failure caused by door interlock failure

according to the design requirements of the elevator: the comprehensive evaluation criteria and industry standards for plastic granulator equipment should be established and improved for each landing door of the elevator, and the elevator can only start running (express) after the car door is closed. If any landing door or car door is not closed, the elevator cannot run

due to the dust accumulation and poor contact of the door lock contact, it causes ignition and leads to the phenomenon of elevator stopping, sometimes good and sometimes bad, but I don't know the fault

because the engagement depth between the lock hook and the door lock stop is too small, the door lock contact is not fully compressed, resulting in poor contact. The national standard engagement depth is greater than 7mm, which also shows that as long as it is greater than 7mm, the contact pressure increases, and poor contact can be avoided

because the gap between the lock hook and the stop is too large, if passengers pick up the door outside the hall door, it will cause the hall door rope breaking switch to disconnect, and the elevator will suddenly stop during operation. The passengers let go and the elevator returned to normal

for such faults, maintenance personnel are required to regularly check whether the door lock contact, gap, hall door wire rope is extended, whether the door connecting rod is loose, and whether the lock hook of the door lock block is deformed and damaged. If problems are found, they should be eliminated in time to reduce unnecessary elevator stopping faults. In reality, it often happens that the elevator stops running and closes people in the car. As the elevator is closed, the personnel in the car panic, kick and pick up, which may damage the elevator at least, or cause personal injury or death. Some fell into the shaft because they couldn't save themselves, and some rescuers panicked to save people, causing them to fall into the shaft. Therefore, it is very important for manufacturers and safety users to pay attention to the installation unit, maintenance personnel and passengers when selecting and reducing the failure of elevator stopping