How To Prevent Elevator Failure

With the advancement of science and technology, the level of design, manufacture, installation, inspection, maintenance, maintenance and use of elevator technology and management has been continuously improved, and the reliability of its operation has been significantly increased. However, in the maintenance, there are still some typical stall failures, of which the elevator can't run the most because of the unreasonable safety loop.

One, phase failure caused by the ladder

When phase failure occurs in the three-phase power supply, the phase sequence relay action cuts off the safety circuit and stops the elevator. This kind of fault is mostly in the elevator logic control elevator, because it is an old-fashioned elevator, the power switch is mostly guillotine type, the power supply passes through the limit switch, and then sent to the elevator control cabinet, the two switches through which the power flows, a total of six fuses. The elevator runs, starts, and the current is very large. After a period of operation, if the maintenance personnel do not check in time, the fuse and screw connection can be easily burned, the elevator is phased off, and the elevator stops.

 The main preventive measures:

a. Maintenance personnel should inspect and inspect frequently, find suspicious areas, repair in time, and hot and sparking situations should be replaced immediately.

b. It is recommended that the user replace the blade switch with a comparable capacity air switch.

c. The elevators that are designed now have no power limit switches. I believe that slight changes can be made to the safety circuit, that is, installing upper and lower limit electrical switches in series in the safety circuit and removing the original limit switches.

 After b.c. processing, this fault can be completely eliminated.

 Second, the riser switch is disconnected and cause a stop

 Like a rope, speed governor ropes will also elongate during use. Due to the effect of the lifting of the bottom pit sheave wheel, the sheave pulley switch hits the plate until the switch is disconnected, causing the elevator to stop.

 In this kind of failure, for newly installed elevators, maintenance personnel are required to check once a month, once a year, and once every three months, so that they can prevent problems. The author encountered several phenomena that resulted in rats being dropped in the pit and slamming into the sheaves to cause three switches to move at the same time. Due to lax airtightness of the hall door and various holes in the hoistway, some rats will crash when they enter the hoistway, and some will fall into the pit because they try to escape and enter the sheave, and the elevator will run down. Causes the safety gear to open and close, and some speed limiter switches work together. There is also a rat in the engine room into the speed limiter, causing the above failures. To solve this type of failure is to prevent rats, can be taken in the engine room, the bottom corner of the pit sprinkled with appropriate mouse drugs and other rat-proof measures to reduce the occurrence of failure. Third, the failure of the door interlock failure

According to the design requirement of the elevator, the elevator can only be started and operated (express train) after each floor door and car door of the elevator are closed. If any floor hall door or car door is not closed, the elevator cannot run.

 Because the door lock contact is dusty and poorly contacted, it causes a fire, which leads to the phenomenon of stopping the ladder. It is good or bad, but I do not know where the fault is.

 Because the depth of engagement of the lock hook and the door lock stopper is too small, the door lock contacts are not fully compressed, resulting in poor contact. The national standard meshing depth is greater than 7mm. From this point of view, as long as the contact pressure is larger than 7mm, the contact failure can be avoided.

 Because the clearance between the hook and the stopper is too large, if the passenger is slamming the door outside the hall door, it will cause the breakage switch of the hall door to be broken and the elevator will suddenly stop during the operation. The passengers let go and the elevator returned to normal.

 Such failures require maintenance personnel to constantly check the door lock contacts, clearances, whether the hall door rope is extended, whether the door links are loosened, and whether the door lock block lock hooks are deformed or damaged. Find problems, eliminate them in time, and reduce unnecessary stop failures. In reality, situations occur when elevators stop running and people are kept in the car. Because elevators are closed, people in the car are panic-stricken and indiscriminately kicking and scrambling. Light elevators damage the elevators, causing heavy casualties. Some will fall into the well because they will not self-rescue, and some rescue personnel panic to save people and cause themselves to fall into the well. Therefore, reducing stop failures is a very important issue for manufacturers, installation units, maintenance personnel and occupants.

Sicher Elevator Co., Ltd.

ADD: NO.1 Sicher Rd, Lianshi Industry Park, Huzhou City, Zhejiang ,China

Contact: Mr. Alex 

Mobile:  +8618868756006

Tel: +86-571-56370866

Fax: +86-571-56192822