Elevator control system malfunctions and causes
1, automatic gate mechanism and door lock circuit failure
All halls, car door because a pre-requisite for elevator operation, interlock system if a failure occurs, the lift will not run. This type of fault is determined by various electrical components, including the automatic door lock contacts bad or improper adjustment.
Investee 2, electric components caused by insulation faults
Electronic and electric components insulated in the long run there by the aging, failure, insulation breakdown caused by damp or for other reasons, resulting in elevator fault caused by electrical system for open circuit or short circuit.
3, components such as relays, contactors, switches, contacts of open circuit or short circuit fault caused by
Made out of relays, contactor control circuits, the fault occurs in the relay contacts, contacts through current or arc erosion, contacts are adhesions can cause a short circuit. If the contacts are dust blocked or Reed contact loses its elasticity will result in circuit breaker, open circuit or short circuit the contacts will make the elevator control circuit failure cause the elevator to malfunction.
4, failures caused by electromagnetic interference,
With the rapid development of computer technology, in particular, greatly reduce the cost of computer applied to elevator control, even with multi-microcomputer serial communication call signals, driven partly by variable voltage (VVVF) speed control system has become a popular standard design of elevator. Frequency in recent years has become the fashion, instead using resistance speed regulation of DC machine. The wide use of computer on the higher reliability of the elevator control system consisting of the demand, mainly anti-jamming reliability. Noise during the operation of the elevator, the main external factors: temperature, humidity, dust, vibration, shock fluctuation of voltage, current, frequency, power, high-frequency interference of the inverter itself, operator errors and changes in load, and so on. In the presence of these disturbances, the elevator will generate an error and fault, Elevator, electromagnetic interference has the following three forms:
(1) power supply noise: it is primarily from the power supply and the power supply line (including the ground wire) to break into the system. Especially when the system with other change often produced when load-sharing power supplies power supply noise. When the power supply lead is long, transmission pressure drops, EMF will generate noise, affecting the normal operation of the system, power supply noise can cause your computer lose part or most of the information, errors or malfunction.
(2) intrusive noise from the input line. When the input lines with their own systems or other systems there is common ground, will enter into the noise, sometimes even using quarantine measures, will still be subject to the input line coupling effect of electromagnetic induction, if when the input signal is very small, easily make errors and malfunction of the system.
(3) static: it is caused by friction, frictional static electricity, is minimal but the voltage of up to tens of thousands of volts. Materials provided by the IEEE reliability Physics Symposium shows that blanket walking man charged up to a maximum of 39KV on a bench next to the person charged can be up to 3KV, so when there is a high potential people exposure to a computer Board, charge-discharge to the system on the human body, sharp noises caused by the discharge current, system, and may even cause damage to the electronic components.
Interference prevention measures must be adopted in view of the above situation, anti-interference measures themselves should be correct and reliable, or a failure of the elevator will occur.
(4) electrical electronic components damaged or location adjustment improper caused of fault: elevator of electrical system, especially control circuit, structure complex, once occurred accident, to quickly excluded fault, single by experience also is enough of, this on requirements maintenance personnel must master electrical control circuit of work principle and the control link of work process, clear all electrical electronic components Zhijian of mutual relationship and role, understand the electrical components of installation location, only such, to accurate to judge fault of occurred points, and quickly be excluded. On this basis if someone and their practical work experience summary and application for rapid troubleshooting and reduces the loss of useful because certain faults in the operation regularly.