Elevator electrical access common failure cases

Elevator electrical access common failure cases
 
At present, China's construction industry is in full swing, high-rise buildings are being built more and more. With the increase of high-rise buildings, elevators are becoming more and more widely used. The electrical fault of elevator is an important factor that causes the safe operation of elevator, so it is necessary to analyze and discuss the electrical fault of elevator, find out the cause of the fault, and take targeted measures and maintenance methods to promote the safe operation of elevator.
 
　　1,the main types and causes of elevator electrical system failure
 
　　1.1 Faults caused by insulation of electrical components
 
 As an important part of the whole elevator electrical system, the electrical components of the elevator will be wet and aging during frequent work. These problems will further cause the elevator electrical components insulation breakdown or operation failure, and even lead to the entire elevator electrical system short circuit or break, which will lead to serious elevator electrical system safety accidents.
 
　　1.2 Faults caused by broken or shorted contacts of electrical components such as contactors, relays, switches, etc
 
 The main control circuits of elevator electrical system are generally composed of contactors, relays, switches and other line components, and the contacts of these components are prone to short-circuit or broken-circuit problems in the elevator's long and frequent work. On the one hand, the arc or high current in the elevator electrical system easily ablation of the contacts of these components and make them adhesion phenomenon, thus causing the electrical system to short circuit;
 
　　1.3 Faults caused by automatic door mechanism and door interlock circuit
 
 The first step in the normal workflow of the elevator is to switch all the doors, layer doors, so the door chain and automatic switching door mechanism circuit to a large extent affect the operation of the elevator. The main cause of this kind of elevator electrical system failure is that the elevator electrical system components have improper position adjustment or poor contact contact and other problems.
 
　　1.4 Faults caused by electromagnetic interference
 
 The types of electromagnetic interference of elevator electrical system are mainly the following kinds, namely input line noise, power supply noise, static noise: input line noise interference is due to the input line and electrical system has a common ground line, so that the input line noise will invade the electrical system, resulting in the elevator electrical system misoperation or operation error; In addition, the supply voltage in the long power supply lead transmission will occur voltage drop, and the electromagnetic induction phenomenon will produce a large noise interference to the electrical system, resulting in the loss of microcomputer data and electrical control system misoperation or operational errors; Although these electrostatic currents are very small, even negligible, but these static voltage is very high, and may even reach tens of thousands of volts, so once the operator or passenger contact the microcomputer panel, the body's high potential charge will quickly transfer to the elevator electrical system with low potential charge, which will lead to discharge phenomenon, which in turn will cause a great deal of discharge current noise interference.
 
　　1.5 Elevator roof or bottom failure caused by relay
 
 Relay caused by the elevator roof or bottom failure frequently occurs for the following three main reasons: If the elevator electrical system slow car circuit damage or failure and other problems, then the elevator electrical system slow car contactor can not absorb, so that the elevator motor can not be in the fast release and brake release stage for the elevator to effectively brake, resulting in the elevator directly across the stratosphere, causing the elevator bottom or roof and other safety accidents; Then the contactor will have a delay release problem. When the elevator is in the fast release stage, this problem will lead to more serious elevator bottom or roof accident, if the elevator electrical system contactor in the slow car deceleration stage short circuit or break the problem, then the elevator system slow car deceleration contactor will not be able to absorb the problem. This will lead to the elevator in the slow-down operation stage of the elevator's torque is not enough, which leads to a serious elevator roof or bottom accident.
 
　　2,elevator electrical fault maintenance methods
 
　　2.1 Static resistance measurement method
 
For static resistance measurement method is mainly the application of resistance gear position to carry out set-up work, with the help of the universal meter this tool to set. For the detection of electrical control circuit resistance to choose the power loss situation, because the structure of electrical components is A PN structure, forward and reverse resistance values will exist in different numbers of values, each electrical component will have a certain number of resistance, in the relevant testing work will be possible to have a resistance of zero or positive infinite situation, through the resistance to carry out detection can be accurately judged on the elevator electrical control system failure.
 
　　2.2 Use the elevator operation process
 
 In the analysis of the cause of the elevator electrical fault, as a maintenance fault staff should have a detailed understanding of the elevator electrical control system circuit principles and elevator operation process. Elevator as an operating tool, its operation is up and down, the complete process is open door, level, speed change, operation, start, close, orientation and layer number selection cycle process. Each link of the elevator has set up different control circuits, through the use of elevator operation technology, the failure analysis, to find out the cause of failure, the use of effective treatment methods to deal with the work.
 
　　2.3 Short-circuit to find
 
 Elevator electrical control circuit is mainly composed of several parts, mainly relays, contactors and switches and other parts, when the system failure, analysis of the cause of possible failure, the analysis focus on contactors, relays on some contacts, through the adoption of wires, contacts short work, if the elevator electrical fault disappears in the power state, it means that the electrical components of the contacts have been damaged, the need for electrical components replacement. When using the short circuit method to find, it is necessary to take full note that the short wiring should be removed immediately after the test is completed for the fault point, and the short wiring should not be used as a contact.
 
　　2.4 Potential measurement
 
 Potential measurement, as an effective detection method used in the event of failure of elevator electrical system, is used to carry out measurement work at both ends of electrical components and electronic equipment while maintaining power. In general, if the electrical can achieve operational operation requires that the current can be in a closed circuit, the entire current flow from high potential to low potential, are following this current direction. As a staff member to repair the electrical system for each potential point to choose the use of a meter to carry out measurement work, the specific location of the fault to find out, analysis of the specific changes in current value, find the cause of the failure, the fault to determine.
 
　　2.5 Break method
 
 If there are some faults in the elevator electrical control circuit, the performance of the failure lies in the elevator does not appear external call instructions or internal selection of the situation when there is a stop layer problem, you can judge the electrical control circuit contact contacts or relay shorting problems. For this failure, you can choose to take a short circuit method for maintenance, the possible failure of the contact to disconnect, if the system can function properly on the right judgment. The circuit break method is mainly used in the electrical control circuit of the "and" logic relationship.
 
　　2.6 Alternatives
 
 For the elevator electrical control system circuit board or a certain point in the operation of certain failures, as an access personnel can be faulty circuit board or components to replace, by replacing the old components or circuit boards, elevator electrical failure disappeared to indicate that the judgment is correct. This approach increases the speed of fault finding and ensures timely replacement in the event of a failure by providing spare parts in the elevator.
 
　　3,enhance the elevator control system troubleshooting and prevention of the recommendations
 
　　3.1 Strengthen the safety responsibility awareness of maintenance personnel
 
 Elevator fault maintenance personnel as the main person in charge of fault maintenance, the main work is to carry out daily maintenance and maintenance of the elevator electrical system control system, to ensure the normal operation of the elevator work. Therefore, we must strengthen the maintenance personnel's sense of safety responsibility, improve the quality of fault service work, fully ensure that the maintenance work can be carried out smoothly to deal with the fault in a timely manner. Enterprises should carry out related safety education and training for the fault-control personnel of elevator control system, and make employees' awareness of safety responsibility obviously improve through safety education activities, and realize their responsibilities through a series of safety activities.
 
　　3.2 Increase daily inspection and maintenance efforts
 
 As an elevator electrical control system maintenance personnel should increase the daily inspection and maintenance efforts, under the conditions allowed by multiple maintenance to ensure the effectiveness of the control system operation. By increasing the daily inspection and maintenance efforts can find the problems of the system in a timely manner, the performance of over-aging components for timely replacement, to ensure the normal and effective operation of elevator electrical control system. By arranging a professional maintenance team to fully ensure the smooth progress of daily maintenance work.
 
　　4,conclusion
 
 Elevator, as a very important transportation tool, has been deeply into the daily work, life in all aspects, is an important part of modern society. In order to ensure the safe operation of the elevator, it is necessary to carry out an in-depth